Risk factors and gender disparity of cognitive impairment among cancer and neurological diseases regarding rural West Texas

Abstract

Background

The prevalence of Alzheimer's disease or dementia is rising among the elderly population in the United States and globally. Sociodemographic, cancer, and neurological disorders are associated with cognitive impairment of people living in rural communities.

Objective

This study identified the association of cognitive impairment with cancer and neurological disorders of the elderly in Cochran and Parmer Counties of rural West Texas.

Methods

Pearson's chi-squared, two-sample independent proportions, binary logistic regression, and multivariable logistic regression methods were utilized to analyze data.

Results

Individuals aged 70 and above experiencing memory loss in Cochran and Parmer Counties had a statistically significant association with cognitive impairment (p < 0.001). In Parmer County, females diagnosed with breast cancer demonstrated a significant relationship with cognitive impairment (p < 0.05). Neurological factors, including muscle strength, cerebellar function, ability to rise from a chair, and Romberg test results, were significantly associated with an increased risk of cognitive impairments among females in both counties. After adjusting for covariates, males aged 60–69 in Parmer County, as well as memory loss among both genders, were significantly associated with cognitive impairment (p < 0.001). Additionally, females with cognitive impairment in Cochran County exhibited higher dependence on mental health services compared to males (p < 0.05).

Conclusions

Examining the association between cognitive impairment or Alzheimer's disease and cancer and neurological disorders is important for developing interventions aimed at reducing their prevalence in underserved rural West Texas Counties.

Keywords

Alzheimer's disease cancer cognitive impairment FRONTIER database rural West Texas

Introduction

Alzheimer's disease (AD) is the most common type of cognitive impairment, accounting for 60–70% of cases and impacting millions of elderly worldwide.^1,2 In AD, tau protein becomes hyperphosphorylated, forming neurofibrillary tangles that disrupt microtubules and leading to axonal degeneration. Neurofibrillary tangles and senile plaques start accumulating 10–20 years before cognitive decline. Early symptoms include memory loss, mood swings, anxiety, poor financial judgment, and reduced decision-making abilities. Advanced AD necessitates full-time care due to severe cognitive impairment such as confusion, disorientation, language and motor issues, and lack of environmental responsiveness.³ Other less common types of dementia such as vascular dementia, Lewy body dementia, and frontotemporal dementia are also known to affect elderly populations. These neurological conditions whether inherited or occurring sporadically, are distinguished by the progressive decline in neuronal structure and function, culminating in cell death and cognitive impairment.⁴

Cognitive impairment has increasingly been observed among elderly populations, with a prevalence rate of 5–29% among those 65 and above in Western countries.⁵ It is estimated that over 57 million individuals worldwide are affected by a form of cognitive impairment, with this figure anticipated to double approximately every 20 years.^5–7 Texas is among the regions with this expected growing trend of cognitive impairment. According to the Alzheimer's Association, nearly half a million Texans aged 65 and older have AD.⁸ Approximately 17% of Texans aged 45 and older report experiencing subjective cognitive decline. Additionally, the cost of AD to the state Medicaid program amounts to $4.3 billion with these costs projected to increase further in the upcoming years.⁸ These trends underscore the relevance of assessing primary risk factors for AD, which include advanced age, family history of AD, genetic predisposition, head trauma, cancer, neurological disorders, and medical conditions such as cardiovascular disease, diabetes, and obesity.^9,10

In this study our focus will be on cancer and neurological disorders as risk factors of cognitive impairment. In fact, research indicates a potential positive association between cancer and cognitive impairment, suggesting that these conditions may share certain risk factors due to overlapping genetical and biological pathways, including cell cycle deregulation.⁸^,10–22 Furthermore, cancer itself can negatively impact brain function; primary and metastatic brain tumors may result in dementia by altering or destroying brain tissue, leading to various symptoms.^9,10 While some studies report evidence supporting a positive association between cancer and cognitive impairment, other findings indicate an inverse relationship.^23–25 For instance, one systematic review and meta-analysis found that colorectal cancer was associated with a reduced risk for all-cause dementia and lung cancer with a reduced risk for AD.²⁶

Research also indicates that neurological symptoms such as parkinsonism frequently occur with cognitive impairment. Conditions including AD, Parkinson's disease, progressive supranuclear palsy, corticobasal degeneration, and tau-positive frontotemporal lobar degeneration may result in cognitive impairment and parkinsonism. Common manifestations include resting tremors, rigidity, and bradykinesia. The onset of these neurological features relative to cognitive impairment varies. Espay and Litvan demonstrated that parkinsonism could precede, coincide with, or follow cognitive impairment resulting from frontotemporal dementia.²⁷ Their findings indicate that individuals with classic progressive supranuclear palsy who display early postural instability and falls, vertical gaze slowing, or supranuclear pseudobulbar parkinsonism are strongly correlated with frontotemporal dementia or its early onset. Conversely, patients experiencing gait or speech freezing without accompanying rigidity, tremor, or sustained response to levodopa, and lacking dementia or ophthalmoplegia within five years, are less strongly associated with frontotemporal dementia or its late onset.

To date, no research addresses the association between cancer and cognitive impairment or the link between cognitive impairment and neurological symptoms in Cochran and Parmer Counties. This initial study aims to identify risk factors related to cancer and neurological disorders, and to evaluate their connection with cognitive impairment in residents of rural West Texas Counties, specifically Cochran and Parmer Counties. The research will analyze sociodemographic data, cancer types, and neurological symptoms to provide more insights into the complex association that exists between cancer, neurologic symptoms, and cognitive impairment or AD within these populations. Cochran County has a population of 2547 and Parmer County 9869. Both are in rural West Texas with notable differences including average household income ($65,575 in Parmer vs. $41,597 in Cochran), poverty rates (9.5% in Parmer vs. 25.8% in Cochran), cognitive difficulty rates (4.2% in Parmer, 8.7% in Cochran), and higher education attainment (18.4% with bachelor's degree or higher in Parmer, 8.5% in Cochran).²⁸

Methods

Data source and study population

A cross-sectional survey was conducted, using convenience sampling methods, among individuals receiving medical care in hospital settings across two major rural counties in West Texas: Cochran and Parmer. A significant portion of the participants reside in isolated rural regions, where access to affordable healthcare and social services is very limited. By utilizing the data collected from this study, initiatives can be developed to effectively control diseases and preserve cognitive abilities over the long term. Project FRONTIER has conducted some research, focused on adults aged 40 years and older, residing in rural communities of West Texas to gain an enhanced understanding of the typical progression of chronic long-term illnesses and their impacts on cognitive, physical, social, and interpersonal well-being. The project has a broader spectrum aim to continue collecting information from the rural West Texas underserved residents to better understand their chronic disease risk factors and to develop intervention models to reduce the risk factors of cognitive impairment. Ultimately, these efforts aim to improve the overall health outcomes of residents in rural West Texas, as noted by FRONTIER in 2006 (Table 1).

Table 1.

Sociodemographic of participants by counties in rural West Texas.

Sociodemographic features	Cochran county	Parmer county
Total population	2547	9869
Older people (65 or above)	16.8%	15.3%
Income and earnings ($)	41,597	65,575
Poverty	25.8%	9.5%
Education (bachelor's degree or higher)	8.5%	18.4%
Health (cognitive difficulty)	8.7%	4.2%
Health insurance without healthcare coverage	19.3%	24.2%
Race and ethnicity (Hispanic or Latino of any race)	1627 (63.87%)	6504 (65.90%)

Sources: https://www.census.gov/acs/www/data/data-tables-and-tools/data-profiles/.²⁸

Sample size and power calculation

The sample size for this study was determined by using G∗Power software (version 3.1.9.7).²⁹ Using logistic regression, it was determined that 197 subjects are required for the study based on a higher percentage of normal cognition than cognitive impairment, assuming 20% individuals higher in normal cognition than cognitive impairment, alpha (α) = 0.05, power = 80%, and a two-sided testing procedure. In most cases, the study samples were large enough for cross-tabulations; however, some cases had small sample sizes, and these cases were dropped from the statistical analysis.

Study participants

Participants in the study were from two major rural West Texas counties, age 40 and above; data were gathered from Project FRONTIER. A questionnaire was developed and provided for hospital participants who visited from Cochran County and Parmer County for their regular health checkups. The questionnaire pattern was binary type (yes or no). Individuals responded to the questions indicating whether they were in normal cognition or experiencing cognitive impairment. The individuals were conscious of cognitive impairment prior to their treatment. Their consciousness of cognitive impairment may be based on interactions reported by physicians or nurses during prior hospital visits, suggesting that patients may have confirmed cognitive concerns with their physicians or nurses. Cognitive status was not reported subjectively, patients visited the hospital for their regular routine health checkup and to maintain healthy lifestyle in West Texas Counties. Data were collected from a recorded digital hospital data frame of the patients who already have health insurance. No methods were used to determine cognitive impairment at the time of study data collection during their visit.

The number of study participations selected in each county is shown in Figure 1. A subtotal of 622 participants is from Cochran County, 683 from Parmer County out of a total of 1305 participants.

Figure 1.

Flow of participants through study.

Data were collected from the Project FRONTIER database, which consists of N = 1305 records. The data were collected during annual resident health check-ups conducted in hospital settings across two major West Texas Counties: Cochran (N1 = 622) and Parmer (N2 = 683). Among the participants, Cochran County (n = 622) had 199 (32.0%) males and 423 (68.0%) female participants. In Parmer County (n = 683), there were 206 (30.2%) male participants and 477 (69.8%) female participants.

Statistical analysis

Data were cleaned and organized for statistical analysis. Descriptive and inferential statistics were employed by using the IBM SPSS (Statistical Package for Social Sciences) software (version 29.0).³⁰ Justification of power and sample size is crucial for conducting meaningful research and it was considered. A summary of statistics was evaluated for sociodemographic, cancer, and neurological disorder for both male and female elderly participants living in rural West Texas Counties. The variables were summarized using number (n) and percent (%). Statistical inference on the null and alternative hypotheses for the proportion of males and females was used to detect significant differences between the counties. Cross-tabulations were used to enumerate the number of responses that meet specific characteristics in each cell frequency, and their results were used for univariate analysis. We used binary logistic regression for bivariate analysis (where the dependent variable was dichotomous outcomes, such as “no/yes” for normal cognition and cognitive impairment; and each independent variable from sociodemographic, cancer, and neurological variables). The odds ratio and its 95% confidence intervals (CI) were calculated. A multivariable logistic regression was performed for statistical analysis after adjusting the covariates, and their adjusted odds ratios and 95% confidence intervals were reported. The p-value (less than 0.05) was used considering the statistical level of significance, alpha (α) = 0.05 to determine if there was an association between risk factors, and the occurrence of cognitive impairment, were reported. To visualize data, bar graphs of the responses of certain variables with no or yes by cognitive impairment were displayed.

Results

This study investigated baseline characteristics such as sociodemographic, cancer and neurological disorders for the elderly participants living within two major counties of rural West Texas. Participants were evaluated based on their binary responses to questions associated with their sociodemographic, cancer and neurological variables relating to whether they had normal cognition or were experiencing cognitive impairment with respect to gender differences. The goal of this study was to detect the relationships between cognitive impairment and risk factors (sociodemographic, cancer, and neurological disorders), so that one can build intervention models to reduce the occurrences of early-stage diseases which lead to AD or dementia and promote a healthy lifestyle in the counties of West Texas. For the detection of significant risk factors, the hypotheses (null: no relationships between risk and outcome variable; and alternative: there is a relationship between risk and outcome variable) were considered.

Table 2 demonstrates the gender differences in Cochran County and Parmer County with their sociodemographic, cancer, and neurological variables. The independent variables considered were age, education, BMI, income, insurance, race/ethnicity, prostrate, colon & rectum, melanoma of the skin, cervix, breast (female), thyroid, uterus, kidney & renal pelvis, memory loss, mental health service, stroke, decreased upward gaze, involuntary movements, sensory intact (hands/feet), muscle strength, cerebellar, reflexes, rising from chair (without using arms), Romberg test result-normal, parkinsonism-tremor, gait-spastic, stiff, narrow, gait-wide-based, unstable, and gait-shuffling. The dependent variable considered is cognitive impairment which is binary in nature (yes or no). Statistical analyses such as cross-tabulation and two-sample proportions tests were carried out to compare the differences in the variables within the counties. The p-value of each variable between genders was calculated to compare with the level of significance, α at 5% or 1% to detect statistically significant variables.

Table 2.

Univariate analysis of baseline characteristics by gender within rural West Texas Counties.

Variables	Cochran County			Parmer County
Variables	Male (n = 199)n (%)	Female (n = 423)n (%)	p	Male (n = 206)n (%)	Female (n = 477)n (%)	p
Sociodemographic
Age group
40–49	38(19.1)	116(27.4)	0.025*	39(18.9)	122(25.6)	0.060
50–59	56(28.1)	124(29.3)	0.763	54(26.2)	127(26.6)	0.911
60–69	50(25.1)	83(19.6)	0.118	52(25.2)	109(22.9)	0.499
70+	55(27.6)	100(23.6)	0.282	61(29.6)	119(24.9)	0.204
Education
None	122(61.3)	275(65.0)	0.369	150(72.8)	342(71.7)	0.765
Certificate	53(26.6)	113(26.7)	0.983	29(14.1)	83(17.4)	0.282
Bachelor	16(8.0)	21(4.9)	0.130	22(10.7)	35(7.3)	0.147
Master	6(3.0)	9(2.1)	0.501	4(1.9)	15(3.1)	0.380
BMI
18.5–24.9	43(21.6)	79(18.7)	0.390	22(10.7)	84(17.6)	0.022*
25–29.9	92(46.2)	140(33.1)	0.002**	92(44.7)	168(35.2)	0.019*
30 and above	58(29.1)	195(46.1)	0.001**	90(43.7)	219(45.9)	0.592
Income
≤$19,999	129(64.8)	292(69.0)	0.295	103(50.0)	160(33.5)	0.001**
$20,000-$39,999	28(14.1)	39(9.2)	0.069	17(8.3)	45(9.4)	0.621
$40,000+	9(4.5)	8(1.9)	0.060	3(1.5)	10(2.1)	0.574
Insurance
No	52(26.1)	140(33.1)	0.079	47(22.8)	135(28.3)	0.137
Yes	147(73.9)	282(66.7)	0.070	159(77.2)	342(71.7)	0.137
Race/ethnicity
Hispanic	82(41.2)	165(39.0)	0.601	84(40.8)	189(39.6)	0.778
Non-Hispanic whites	102(51.3)	217(51.3)	0.992	119(57.8)	283(59.3)	0.703
Cancer
Prostate
No	18(9.0)	45(10.6)	0.539	21(10.2)	65(13.6)	0.215
Yes	8(4.0)	0(0.0)	0.001**	6(2.9)	0(0.0)	0.001**
Colon & rectum
No	21(10.6)	44(10.4)	0.954	26(12.6)	59(12.4)	0.927
Yes	5(2.5)	1(0.2)	0.007**	1(0.5)	6(1.3)	0.358
Melanoma of the skin
No	21(10.6)	39(9.2)	0.599	14(6.8)	46(9.6)	0.228
Yes	5(2.5)	6(1.4)	0.334	13(6.3)	19(3.9)	0.186
Cervix
No	26(13.1)	42(9.9)	0.242	27(13.1)	60(12.6)	0.849
Yes	0(0.0)	3(0.7)	0.234	0(0.0)	5(1.0)	0.140
Breast (female)
No	26(13.1)	34(8.0)	0.048	27(13.1)	44(9.2)	0.127
Yes	0(0.0)	11(2.6)	0.022*	0(0.0)	21(4.4)	0.002**
Thyroid
No	25(12.6)	43(0.1)	0.371	27(13.1)	64(13.7)	0.912
Yes	1(0.5)	2(0.5)	0.960	0(0.0)	1(0.2)	0.510
Uterus
No	26(13.1)	36()	0.077	27(13.1)	55(11.5)	0.561
Yes	0(0.0)	9()	0.038*	0(0.0)	10(2.1)	0.036*
Kidney & renal pelvis
No	25(12.6)	43(0.1)	0.371	26(12.6)	65(13.6)	0.723
Yes	1(0.5)	2(0.5)	0.960	1(0.5)	0(0.0)	0.128
Neurological
Memory loss
No	137(68.8)	327(77.3)	0.024*	167(81.1)	406(85.1)	0.187
Yes	61(30.7)	92(21.7)	0.016*	30(14.6)	45(9.4)	0.049
Mental health service
No	81(40.7)	179(42.3)	0.704	110(53.4)	219(45.9)	0.072
Yes	0(0.0)	11(2.6)	0.022*	0(0.0)	6(1.3)	0.106
Stroke
No	77(38.7)	184(43.5)	0.237	89(43.2)	194(40.7)	0.537
Yes	1(0.5)	1(0.2)	0.584	1(0.5)	3(0.6)	0.821
Decreased upward gaze
No	186(93.5)	403(95.3)	0.669	153(74.3)	367(76.9)	0.453
Yes	5(2.5)	5(1.2)	0.218	3(1.5)	2(0.4)	0.144
Involuntary movements
No	185(92.9)	394(93.1)	0.934	155(75.2)	363(76.1)	0.810
Yes	6(3.0)	13(3.1)	0.968	1(0.5)	1(0.2)	0.540
Sensory intact (hands/feet)
No	161(80.9)	358(84.6)	0.243	151(73.3)	362(75.9)	0.472
Yes	3(1.5)	5(1.2)	0.736	5(2.4)	7(1.5)	0.381
Muscle strength
No	173(86.9)	159(37.6)	0.001**	145(70.4)	346(72.5)	0.566
Yes	18(9.0)	48(11.3)	0.384	11(5.3)	23(4.8)	0.775
Cerebellar
No	190(95.5)	397(93.9)	0.412	146(70.9)	356(74.6)	0.307
Yes	1(0.5)	6(1.4)	0.312	10(4.9)	12(2.5)	0.112
Reflexes
No	186(93.5)	402(95.0)	0.422	151(73.3)	365(76.5)	0.369
Yes	5(2.5)	4(0.9)	0.127	5(2.4)	4(0.8)	0.095
Rising from chair (without using arms)
No	44(22.1)	81(19.1)	0.389	7(3.4)	15(3.1)	0.863
Yes	147(73.9)	325(76.8)	0.420	149(72.3)	354(74.2)	0.608
Romberg test result-normal
No	21(10.6)	58(13.7)	0.269	10(4.9)	15(3.1)	0.275
Yes	169(84.9)	344(81.3)	0.271	145(70.4)	353(74.0)	0.329
Parkinsonism – tremor
No	187(93.9)	401(94.8)	0.671	154(74.9)	366(76.7)	0.579
Yes	4(2.0)	6(1.4)	0.584	2(0.9)	3(0.6)	0.630
Gait – spastic, stiff, narrow
No	175(87.9)	380(89.8)	0.477	154(74.9)	366(76.7)	0.579
Yes	13(6.5)	26(6.1)	0.853	2(0.9)	2(0.4)	0.386
Gait – wide-based, unstable
No	180(90.5)	377(89.1)	0.613	154(74.9)	366(76.7)	0.579
Yes	9(4.5)	26(6.1)	0.412	2(0.9)	2(0.4)	0.386
Gait – shuffling
No	178(89.4)	376(88.9)	0.835	155(75.2)	368(77.1)	0.589
Yes	9(4.5)	26(6.1)	0.412	1(0.5)	0(0.0)	0.128
Cognitive Impairment
No	127(63.8)	302(71.4)	0.056	142(68.9)	381(79.9)	0.002**
Yes	72(36.2)	119(28.1)	0.042*	62(30.1)	82(17.2)	0.001**

n: sample size; %: percentage; p: p-value; *p < 0.05, **p < 0.01; BMI: body mass index, percentages are presented within parentheses.

Table 2 illustrates the baseline characteristics of study participants by gender across two West Texas Counties. Of the 1305 participants, 405 (31.0%) were males and 900 (69.0%) were females. Among the sociodemographic, cancer, and neurological variables, significant statistical differences were obtained between the number of male and female individuals in the 40–49 age group category (p < 0.05) in Cochran County. In Cochran and Parmer Counties, the significant differences (p < 0.05) between male and female individuals were obtained those who had a BMI between 25 and 29.9. The significant difference (p < 0.001) in the number of male and female individuals who had a BMI above 30 was found in Cochran County. Prostrate, breast, and uterus cancer were found to be significantly different (p < 0.005) in the number of male and female individuals for both counties.

Table 3 exhibits the results of bivariate analysis for the variables using binary logistic regression with outcome or dependent variable cognitive awareness (normal or cognitive impairment) and explanatory or independent risk variable. The male individuals in age group 60–69 were found to be significantly associated with cognitive impairment for Cochran County (OR: 2.1, 95% CI: (1.0, 4.3)); and both male and female individuals in the same age group were found to be significantly associated with cognitive impairment in Parmer Counties (OR: 4.0, 95% CI: (1.2, 13.1); OR: 3.1, 95% CI: (1.3, 7.1)). A significant association with cognitive impairment was also found for age group 70 and over for Cochran County (male, OR: 4.8, 95% CI: (1.9, 12.5)) and female OR: 5.1, 95% CI: (2.6, 9.7), and Parmer County (male, OR: 9.7, 95% CI: (3.1, 30.8) and female OR: 5.6, 95% CI: (2.6, 12.2)).

Table 3.

Bivariate analysis of factors associated with the prevalence of cognitive impairment by gender.

Variables	Cochran County		Parmer County
Variables	Male (n = 199)OR (95% CI)	Female (n = 423)OR (95% CI)	Male (n = 206)OR (95% CI)	Female (n = 477)OR (95% CI)
Sociodemographic
Age group
40–49	(ref)
50–59	1.6(0.6–4.3)	2.2*(1.2–4.3)	1.4(0.4–5.2)	1.8(0.8–4.2)
60–69	1.8(0.7–4.7)	2.1*(1.0–4.3)	4.0*(1.2–13.1)	3.1**(1.3–7.1)
70+	4.8**(1.9–12.5)	5.1**(2.6–9.7)	9.7**(3.1–30.8)	5.6**(2.6–12.2)
Education
None	(ref)
Certificate	0.6(0.3–1.2)	0.8(0.5–1.3)	0.4(0.1–1.1)	0.8(0.4–1.4)
Bachelor	0.1(0.0–0.7)	0.5(0.2–1.6)	0.5(0.1–1.4)	0.2(0.1–1.1)
BMI
18.5–24.9	(ref)
25–29.9	0.9(0.4–1.9)	0.8(0.4–1.4)	1.1(0.4–3.0)	1.2(0.6–2.3)
30+	0.7(0.3–1.6)	0.8(0.5–1.4)	0.7(0.3–1.9)	0.7(0.4–1.4)
Income
≤$19,999	(ref)
$20,000-$39,999	0.6(0.3–1.5)	0.7(0.3–1.7)	0.6(0.2–2.4)	0.8(0.3–2.1)
$40,000+	0.5(0.1–2.3)	0.9(0.2–4.7)	1.5(0.1–17.0)	–
Insurance
No	(ref)
Yes	2.0(1.0–4.1)	1.7*(1.1–2.7)	1.5(0.7–3.1)	1.1(0.6–1.7)
Race/ethnicity
Hispanic	(ref)
Non-Hispanic whites	1.7(0.9–3.2)	1.0(0.6–1.5)	1.9*(1.1–3.6)	1.1(0.7–1.8)
Cancer
Prostate
No	(ref)
Yes	2.6(0.5–14.6)	1.2(0.7–2.5)	6.4(0.9–45.9)	0.9(0.5–1.8)
Colon & rectum
No	(ref)
Yes	0.4(0.0–4.3)	–	–	–
Melanoma of the skin
No	(ref)
Yes	–	1.7(0.3–10.6)	0.4(0.1–2.1)	1.9(0.6–7.1)
Cervix
No	(ref)
Yes	1.1(0.5–2.6)	1.6(0.1–19.6)	0.8(0.4–1.9)	–
Breast(female)
No	(ref)
Yes	1.1(0.5–2.6)	2.2(0.5–9.7)	0.8(0.4–1.9)	3.8*(1.0–13.9)
Thyroid
No	(ref)
Yes	–	3.3(0.2–57.6)	0.8(0.4–1.9)	–
Uterus
No	(ref)
Yes	1.1(0.5–2.6)	0.3(0.0–2.9)	0.8(0.4–1.9)	–
Kidney & renal pelvis
No	(ref)
Yes	–	–	–	0.8(0.3–1.9)
Neurological
Memory loss
No	(ref)
Yes	11.4**(5.2–24.7)	20.9**(11.5–38.4)	50.1**(11.2–223.7)	83.6**(28.2–247.9)
Mental health service
No	(ref)
Yes	–	2.4*(0.7–8.8)	–	0.9(0.1–8.7)
Decreased upward gaze
No	(ref)
Yes	2.5(0.4–15.6)	3.8(0.6–23.3)	–	–
Involuntary movements
No	(ref)
Yes	3.4(0.6–19.3)	4.3*(1.4–13.4)	–	2.7(0.5–14.6)
Sensory intact (hands/feet)
No	(ref)
Yes	1.6(0.7–3.4)	2.9**(1.6–5.5)	8.9(0.9–81.4)	0.9(0.1–7.3)
Muscle strength
No	(ref)
Yes	1.7(0.7–4.6)	2.4**(1.3–4.4)	1.2(0.3–4.3)	4.6**(1.9–11.1)
Cerebellar
No	(ref)
Yes	–	13.2*(1.5–113.9)	3.4(0.9–12.5)	4.0*(1.2–12.9)
Reflexes
No	(ref)
Yes	1.1(0.2–6.8)	7.7(0.8–75.2)	3.2(0.5–19.8)	16.4*(1.7–160.4)
Rising from chair (without using arms)
No	(ref)
Yes	4.1(2.0–8.3)	2.7**(1.6–4.5)	2.9(0.6–13.4)	9.1**(3.1–26.5)
Romberg test result-normal
No	(ref)
Yes	3.1*(1.3–7.9)	3.7**(2.1–6.6)	3.3(0.0–12.4)	5.1**(1.8–14.8)
Parkinsonism – tremor
No	(ref)
Yes	0.5(0.1–5.3)	1.3(0.2–7.0)	–	–
Gait – spastic, stiff, narrow
No	(ref)
Yes	6.2**(1.6–23.5)	3.2**(1.4–7.2)	2.1(0.1–33.9)	5.3(0.3–85.3)
Gait – wide-based, unstable
No	(ref)
Yes	1.3(0.3–5.1)	2.3*(1.0–5.1)	–	–
Gait – shuffling
No	(ref)
Yes	3.5(0.9–14.7)	6.5**(2.8–15.5)	–	–

− indicates that data were not available due to small size or missing due to nonresponse; n: sample size; %: percentage; p: p-value; *p < 0.05, **p < 0.01; ref: referent group; OR: odds ratio; CI: confidence interval; BMI: body mass index.

Health insurance coverage is very important to maintain a quality of life. It protects individuals from financial risks associated with physical and psychological disorders, and the expenses for the treatment of unexpected situations like accidents or person's health illnesses and disease related to short term and long-term health complications. It was found that individuals in Cochran County had higher cognitive difficulty (8.7%) than Parmer County (4.2%), and there were more older people (65 or above) living in Cochran County (16.8%) than in Parmer County (15.3%).²⁸ The females who have health insurance in Cochran County were found to be significantly associated with cognitive impairment (OR: 1.7, 95% CI: (1.1, 2.7)). The females with breast cancer in Parmer County were found to be significantly associated with cognitive impairment (OR: 3.8, 95% CI: (1.0, 13.9)). The male and female individuals with neurological disorder such as memory loss were found to be significantly associated with cognitive impairment in both counties. The females with muscle strength (OR: 2.4, 95% CI: (1.3, 4.4), OR: 4.6, 95% CI: (1.9, 11.1)), cerebellar (OR: 13.2, 95% CI: (1.5, 113.9), OR: 4.0, 95% CI: (1.2, 12.9)), rising from chair (OR: 2.7, 95% CI: (1.6, 4.5), OR: 9.1, 95% CI: (3.1, 26.5)), Romberg test result (OR: 3.7, 95% CI: (2.1, 6.6), OR: 5.1, 95% CI: (1.8, 14.8)) in both Cochran and Parmer Counties, respectively were found to be significantly associated with cognitive impairment. The males (OR: 6.2, 95% CI: (1.6, 23.5)) and females (OR: 3.2, 95% CI: (1.4, 7.2)) with gait-spastic, stiff, narrow in Cochran County were found to be significantly associated with cognitive impairment. The female individuals in gait-wide-based, unstable (OR: 2.3, 95% CI: (1.0, 5.3)) and gait shuffling (OR: 6.5, 95% CI: (2.8, 15.5)) in Cochran County were found to be significantly associated with cognitive impairment.

Table 4 illustrates the results of multivariable analysis for the variables using a binary logistic regression with dichotomous outcome or dependent variables of cognitive awareness (normal or cognitive impairment) and explanatory or independent risk factors. All the independent variables were considered in the logistic regression model and after controlling the covariates the following independent variables were selected in the final model: age, education, BMI, income, insurance, race/ethnicity, prostrate, colon & rectum, memory loss, mental health service, decreased upward gaze, involuntary movements, sensory intact (hands/feet), muscle strength, cerebellar, reflexes, rising from chair (without using arms), Romberg test result-normal, parkinsonism-tremor, gait-spastic, stiff, narrow, gait-wide-based, unstable, and gait-shuffling. Statistical analysis results such as adjusted odds ratio (OR^δ) and its 95% CI were reported in Table 4 to compare gender differences in terms of risk factors between the counties. The p-value was used to compare with the level of significance, α at 5%, to detect statistically significant risk variable.

Table 4.

Multivariable analysis of factors associated with cognitive impairment by gender after adjustment for covariates.

Variables	Cochran County		Parmer County
Variables	Male (n = 199)OR^δ (95% CI)	Female (n = 423)OR^δ (95% CI)	Male (n = 206)OR^δ (95% CI)	Female (n = 477)OR^δ (95% CI)
Sociodemographic
Age group
40–49	(ref)
50–59	0.9(0.2–4.3)	5.0(1.0–25.9)	4.5(0.4–46.9)	0.6(0.0–7.8)
60–69	0.9(0.2–4.9)	3.3(0.5–20.9)	41.5**(2.9–584.2)	3.0(0.4–25.1)
70+	1.4(0.2–8.1)	0.6(0.0–17.5)	–	5.7(0.2–197.1)
Education
None	(ref)
Certificate	0.5(0.2–1.8)	2.2(0.4–12.9)	2.9(0.3–33.1)	0.9(0.1–15.3)
Bachelor	0.1*(0.0–0.9)	–	17.4(0.4–861.5)	–
BMI
18.5–24.9	(ref)
25–29.9	2.3(0.5–11.1)	0.6(0.1–5.4)	0.4(0.0–8.0)	0.4(0.0–11.4)
30+	1.7(0.3–9.4)	1.1(0.2–8.3)	0.1(0.0–2.1)	0.9(0.0–16.5)
Income
≤$19,999	(ref)
$20,000-$39,999	0.3(0.0–2.2)	16.54(0.9–298.5)	1.9(0.2–16.4)	2.5(0.2–35.1)
$40,000+	0.6(0.1–5.8)	–	13.9(0.3–552.4)	–
Insurance
No	(ref)
Yes	0.9(0.2–3.8)	0.4(0.1–1.6)	0.7(0.1–4.3)	0.9(0.2–5.3)
Race/ethnicity
Hispanic	(ref)
Non-Hispanic whites	1.0(0.3–3.4)	10.1(0.7–1.37.2)	–	–
Cancer
Prostate
No	(ref)
Yes	1.8(0.6–55.8)	–	0.1(0.0–2.9)	–
Colon & rectum
No	(ref)
Yes	0.6(0.0–31.2)	–	–	–
Neurological
Memory loss
No	(ref)
Yes	10.7**(2.9–38.6)	10.9**(1.9–63.9)	–	–
Mental health service
No	(ref)
Yes	–	11.3*(1.0–126.9)	–	–
Decreased upward gaze
No	(ref)
Yes	0.6(0.0–16.6)	–	–	–
Involuntary movements
No	(ref)
Yes	1.3(0.0–54.6)	–	–	–
Sensory intact (hands/feet)
No	(ref)
Yes	0.9(0.1–7.7)	0.6(0.0–15.8)	–	–
Muscle strength
No	(ref)
Yes	1.4(0.1–28.1)	3.1(0.3–35.9)	–	–
Cerebellar
No	(ref)
Yes	–	0.4(0.0–83.1)	–	–
Reflexes
No	(ref)
Yes	0.7(0.0–47.8)	–	–	–
Rising from chair (without using arms)
No	(ref)	2.0(0.4–10.7)	–	–
Yes	0.6(0.1–4.2)
Romberg test result-normal
No	(ref)
Yes	0.6(0.1–5.0)	0.4(0.0–4.1)	–	–
Parkinsonism – tremor
No	(ref)
Yes	0.5(0.0–69.7)	–	–	–
Gait – spastic, stiff, narrow
No	(ref)
Yes	9.3(0.8–109.9)	1.5(0.0–119.0)	–	–
Gait – wide-based, unstable
No	(ref)
Yes	1.1(0.1–20.7)	–	–	–
Gait – shuffling
No	(ref)
Yes	3.5(0.9–14.7)	–	–	–

There was a significant relationship between the age group 60–69 and cognitive impairment for males in Parmer County, OR^δ: 41.5, 95% CI: (2.9, 584.2). Male bachelor's degree holders were less likelihood of developing cognitive impairment (OR^δ: 0.1, 95% CI: (0.0, 0.9)) than male and female certificate degree holders (OR^δ: 0.5, 95% CI: (0.2, 1.8) and OR^δ: 2.2, 95% CI: (0.4, 12.9)) in Cochran County. The participants those who were obese in Parmer County had a less likelihood of cognitive impairment (OR^δ: 0.1, 95% CI: (0.0, 2.1) and OR^δ: 0.9, 95% CI: (0.0, 16.5)) than that of Cochran County (OR^δ: 1.7, 95% CI: (0.3, 9.4) and OR^δ: 1.1, 95% CI: (0.2, 8.3)) but they were not found statistically significant.

Male individuals who had income at least $20,000 have found to be a lower risk (OR^δ: 0.3, 95% CI: (0.0, 2.2) and OR^δ: 0.6, 95% CI: (0.1, 5.8)) of developing Cognitive impairment than the males in Parmer County (OR^δ: 0.1.9, 95% CI: (0.2, 16.4) and OR^δ: 13.9, 95% CI: (0.3, 552.4)) but they were not found statistically significant. Individuals having health insurance services were found to have a low likelihood of developing cognitive impairment in both counties, but they were not found statistically significant.

Memory loss in male and female individuals living in Cochran County were found to be highly significant (OR^δ: 10.7, 95% CI: (2.9, 38.6) and OR^δ: 10.9, 95% CI: (1.9, 63.9)). Mental health service in females was found to be significant in Cochran County (OR^δ: 11.3, 95% CI: (1.0, 126.9)).

Figure 2 portrays a visual representation of the cognitive impairment of males and females living in Cochran and Parmer Counties. It was observed that there was a higher number of female individuals compared to male counterparts in each county. The highest number of male individuals was observed in Parmer County (n = 206) compared to Cochran County (n = 199). The cognitive impairment of male individuals represents 36.2% of the total 199 participants in Cochran County. Similarly, of the 206 male individuals in Parmer County, 30.1% of individuals were cognitively impaired. On the other hand, the female individuals in Parmer County had the highest participation (n = 477) with relatively a lower percentage of cognitive impairment (17.2%) compared to Cochran County (28.1%), respectively. The females had a relatively higher percentage of cognitive impairment compared with male counterparts in the counties.

Figure 2.

Comparison of cognitive impairment between males and females in counties. Gender-specific cognitive decline within two rural West Texas counties. The percent of participants belongs on the y-axis, and gender and cognitive impairment are on the x-axis of the graph. Each of the bars indicates the number of participants. Project FRONTIER collected data from two counties, (2006–2018): Cochran County (for males, number of participants n = 199, cognitive decline n = 72; for females, number of participants n = 423, cognitive decline n = 119), Parmer County (for males, number of participants n = 206, cognitive decline n = 62; for females, number of participants n = 477, cognitive decline n = 82).

Figure 3 describes memory loss by males and females. Cognitive impairment is assessed by the number of responses to questions. The response ‘No’ is defined as no memory loss or slight inconsistent forgetfulness. Yes1 is defined as consistent slight forgetfulness, partial recollection. Yes2 is defined as moderate memory loss, more marked for recent events; and Yes3 is for severe memory loss, only highly learned material. The highest responded observed for Yes1 in females is Cochran County than the females in Parmer County. The males were lower memory loss for Yes1 and Yes3 than females in both counties. The females were slightly lower memory loss for Yes2 compared to male counterparts.

Figure 3.

Cognitive impairment assessed with questions in rural West Texas. Gender-specific cognitive status within two rural West Texas counties. The number of participants belongs to the y-axis and genders are on the x-axis of the graph. Project FRONTIER collected data from two counties, (2006–2018). On the x-axis, the term No is defined with no memory loss or slight inconsistent forgetfulness; Yes1 is defined as consistent slight forgetfulness, partial recollection; Yes2 is defined as moderate memory loss, more marked for recent events; and Yes3 is for severe memory loss, only highly learned material. Cochran County by male gender (no cognitive impairment, n = 137, and cognitive impairments based on yes responses, n = 46, 14, 1; by female gender (no cognitive impairment, n = 327, and cognitive impairments based on yes responses, n = 81, 9, 2). Similarly, for Parmer County by male gender (no cognitive impairment, n = 167, and cognitive impairments based on yes responses, n = 25, 4, 1; by female gender (no cognitive impairment, n = 406, and cognitive impairments based on yes responses, n = 39, 3, 3).

Figure 4 displays the distribution of memory loss responses with age groups 40–49, 50–59, 60–69, and 70+ in the counties. It was noticeable that a large proportion of female individuals in Cochran County who had suffered memory loss with consistent slight forgetfulness, and partial recollection compared to males in Cochran County. Those who had moderate memory loss, more marked for recent events, were observed higher in males than females in Cochran County. The female individuals with severe memory loss, only highly learned material, were higher than males in Cochran County. It was observed that a large proportion of female individuals in Parmer County who had suffered memory loss with consistent slight forgetfulness, and partial recollection compared to males in the same county. The higher number of males with moderate memory loss, more marked for recent events observed than females in Parmer County. The higher number of females with severe memory loss, only highly learned material was observed than males in Parmer County.

Figure 4.

Memory loss assessed with questions in rural West Texas. Gender and age-specific memory loss in two rural West Texas counties. The number of responses belong on the y-axis, and age, gender, and county are on the x-axis of the graph. Project FRONTIER collected data from two counties, (2006–2018). On the x-axis, the term No is defined with no memory loss or slight inconsistent forgetfulness; Yes1 is defined as consistent slight forgetfulness, partial recollection; Yes2 is defined as moderate memory loss, more marked for recent events; and Yes3 is for severe memory loss, only highly learned material. Cochran County by male gender (no memory loss, n = 137, and memory loss with age groups based on yes1 responses, n = 6, 11, 11, 18; yes2 responses, n = 1, 4, 3, 6; yes3 responses, n = 0, 0, 0, 1; by female gender (no memory loss, n = 327, and memory loss with age groups based on yes1 responses, n = 9, 21, 15, 36; yes2 responses, n = 1, 1, 0, 7; yes3 responses, n = 0, 0, 1, 1. Similarly, for Parmer County by male gender (no memory loss, n = 167, and memory loss with age groups based on yes1 responses, n = 1, 3, 5, 16; yes2 responses, n = 0, 1, 0, 3; yes3 responses, n = 0, 0, 0, 1; by female gender (no memory loss, n = 406, and memory loss with age groups based on yes1 responses, n = 4, 6, 10, 19; yes2 responses, n = 0, 0, 0, 3; yes3 responses, n = 1, 0, 1, 1.

The males in Cochran County with age groups 60–69 and 70+ were observed (n = 29) the higher number than Parmer County (n = 21) who suffered with consistent slight forgetfulness, partial recollection. The similar trend was observed with age groups 60–69 and 70+ who suffered with moderate memory loss, more marked for recent events in Cochran County (n = 9) and Parmer County (n = 3). Comparing with the female individuals between the counties with age groups 60–69 and 70+, the higher individuals were observed in Cochran County (n = 51) who suffered with consistent slight forgetfulness, partial recollection than Parmer County (n = 29), similarly, the higher individuals were observed in Cochran County (n = 7) who had moderate memory loss, more marked for recent events than Parmer County (n = 3). There were two female individuals with age groups 60–69 and 70+ in Cochran County who had severe memory loss, only highly learned material than one female individual in Parmer County.

Figure 5 exhibits a visual comparison of males and females in cognitive impairment with classifications AACI = age-associated cognitive impairment, CIND = cognitive impairment no dementia, MCI = mild cognitive impairment, and dementia between the two counties. The male individuals in Cochran County had a large proportion of CIND (n = 9), MCI (n = 46), and dementia (n = 9) compared to male individuals, CIND (n = 7), MCI (n = 32), and dementia (n = 5) in Parmer County. The proportion of females in Cochran County had higher cognitive impairment AACI (n = 28), CIND (n = 13), MCI (n = 72), and dementia (n = 6) compared to the females in Parmer County, AACI (n = 15), CIND (n = 6), MCI (n = 58), and dementia (n = 3).

Figure 5.

Cognitive classifications measured by gender. Gender-specific cognitive classifications measured within two rural West Texas counties. The number of participants belong on the y-axis and cognitive measurement classifications (normal, AACI = age-associated cognitive impairment, CIND = cognitive impairment no dementia, MCI = mild cognitive impairment, and dementia) on the x-axis of the graph. Project FRONTIER collected data from two counties, (2006–2018). The Cochran and Parmer Counties on the cognitive measurement levels for male responses, normal (n = 127, 142), AACI (n = 8, 18), CIND (n = 9, 7), MCI (n = 46, 32), and dementia (n = 9, 5), respectively. Similarly, the Cochran and Parmer Counties on the cognitive measurement levels for female responses, normal (n = 302, 381), AACI (n = 28, 15), CIND (n = 13, 6), MCI (n = 72, 58), and dementia (n = 6, 3), respectively.

Discussion

This study investigated cancer and neurological related cognitive impairment in Cochran and Parmer Counties, with the aim of addressing health outcomes in West Texas. The goal of this study aligned with Project FRONTIER mission, which began in 2006 as a long-term study of adults aged 40 and over in rural West Texas and examined chronic, physical, mental, and cognitive health issues. By collecting health and demographic data from 2006–2018 in underserved counties, the project aimed to identify factors associated with disease progression and inform interventions intended to reduce dementia risk in these populations.^31,32

The analysis of data from Project FRONTIER highlighted notable findings. Cochran County showed significant gender differences in the 40–49 age group category, in the prevalence of BMI both overweight (25–29.9) and obese (30 and above), prostate cancer, colon and rectum cancer, female breast cancer, uterus cancer, and neurological symptoms such as memory loss, cognitive impairment, muscle strength, and use of mental health services. Parmer County also revealed notable gender disparity in the prevalence of BMI 18.5–24.9 and overweight (25–29.9), in annual income ≤ 19,999, prostate cancer, female breast cancer, uterus cancer, and cognitive impairment. Prostate cancer prevalence among males was higher in Cochran County (4%) than in Parmer County (2.9%). Female breast cancer rates were higher in Parmer County (4.4%) compared to Cochran County (2.6%). Significant associations with cognitive impairment were observed for the following variables: individuals aged 50 and over in Cochran County and 60 and over in Parmer County, health insurance coverage among females in Cochran County, the non-Hispanic white race/ethnicity group in Parmer County, female breast cancer prevalence in Parmer County, utilization of mental health services by females in Cochran County, and several neurological factors. Neurological factors such as memory loss in males and females in both counties, involuntary movements among females in Cochran County, muscle strength and cerebellar symptoms in females, difficulty rising from a chair, Romberg test results in both Cochran and Parmer Counties, gait abnormalities including spastic, stiff, and narrow gait in both males and females in Cochran County, and wide-based, unstable, or shuffling gait among females in Cochran County were all found to have significant associations with cognitive impairment. After adjusting for covariates, male aged 60–69 in Parmer County, memory loss among males and females in Cochran County, and female use of mental health services in Cochran County were linked to cognitive impairment. Males with bachelor's degree in Cochran County, were associated with lower odds of cognitive impairment.

The data in Table 2 indicates gender differences in sociodemographic factors, cancer prevalence, and neurological disorders. Our results on sociodemographic base on gender revealed that in Parmer County, differences between genders were identified in sociodemographic variables such as age 40–49, reported at 27.4% for females and 19.1% for males showing that more females fell in this age group as reported in the US census data.²⁸ Annual income of $19,999 or less also showed a notable difference by gender, with 50.0% of males and 33.5% of females falling into this category. The findings indicate that men in Parmer County have lower incomes and may be facing socioeconomic challenges, including limited access to quality employment opportunities and reduced healthcare coverage.²⁸

Gender differences in cognitive impairment were observed in both counties: Parmer County had a larger gap (12.9%) between males (30.1%) and females (17.2%), while Cochran County's gap was 8.1% (males 36.2%, females 28.1%). The data indicate that males exhibit a higher prevalence of cognitive impairment than females in both counties. These findings are consistent with those of Levine et al., who observed that females had superior baseline performance in global cognition, executive function, and memory.³³ Our study included younger females (aged 40 and above) who may possess greater cognitive reserve compared to males within the same age range, which could account for the lower incidence of cognitive impairment among women in both Cochran and Parmer Counties. However, it is important to note that the sex differences in cognitive impairment remain unclear. Notably, Levine et al. have also reported that women experienced a more rapid decline in global cognitive reserve than men, though this trend did not extend to memory.³³ Furthermore, some research suggesting a higher prevalence of cognitive impairment among females posits that increased longevity in women results in a faster rate of decline once mild cognitive impairment develops, relative to men.^34,35

Both counties reported the same prevalence of uterus cancer (2.1%) while female breast cancer rates were higher in Parmer County (4.4%) than in Cochran County (2.6%). There was a higher prevalence of prostate cancer among males in Cochran County (4%) compared to Parmer County (2.9%). In Cochran County, there was a gender disparity in cancer with a higher prevalence of colon and rectum cancer among males 2.5% compared to 0.2% among females. These findings on colon and rectum cancer are consistent with the results found by White et al., who reported a higher prevalence of colorectal cancer among men.³⁶ While the present study did not examine the causes of these disparities, White et al. suggested that a combination of biological factors and gender-specific behaviors, such as lower screening participation, increased health risk behaviors like alcohol consumption, and a higher likelihood of tobacco use among men, may contribute to the increased risk.^36,37

The results of bivariate analysis of factors associated with the prevalence of cognitive impairment by gender in Table 3 revealed that age, race/ethnicity, cancer, health insurance coverage, and neurological factors all showed significant associations with cognitive impairment. The data revealed that in Cochran County, females aged 50 and above and males aged 70 and above exhibited higher prevalence rates compared to individuals aged 40–49. Similarly, in Parmer County, individuals aged 60 and above demonstrated increased prevalence relative to the 40–49 age group. Overall, the prevalence of cognitive decline was found to rise with advancing age, reaching its highest level among those aged 70 and above in both counties. These results are consistent with other studies that showed higher cognitive decline prevalence among older adults.^9,34,38 This trend shows that advanced age is an important factor in the development of dementia.

In Cochran County, individuals aged 50–59 demonstrated a statistically significant association with cognitive impairment, occurring a decade earlier than in Parmer County, where significance was observed in those aged 60 and above. This ten-year disparity may be due to less favorable social determinants of health in Cochran County compared to Parmer County. Data from the US Census Bureau indicates that Cochran County experiences higher rates of cognitive difficulty, greater poverty levels, lower educational attainment, and reduced average household income relative to Parmer County.²⁸ Nevertheless, these factors do not fully account for the observed difference. The present study did not investigate these variables; therefore, further research is warranted to examine the underlying causes of the ten-year gap between Cochran and Parmer Counties.

This study indicated that race/ethnicity is associated with statistically significant differences in the prevalence of cognitive impairment. In Parmer County, non-Hispanic White male individuals had higher odds of cognitive impairment compared to Hispanic individuals (OR: 1.9, 95% CI: (1.1, 3.6)). Luo et al. reported comparable observations, noting an increase in the rate of cognitive impairment among non-Hispanic White respondents from 5.2% in 1997 to 6.1% in 2015; while no significant trends were found in other groups. Luo et al. adjusted for covariates and found that Asian, non-Hispanic Black, Hispanic, and Native American respondents were more likely than non-Hispanic White respondents to report cognitive impairment.³⁹

Several prior studies demonstrated a significant association between cancer and cognitive impairment,^40–43 often attributable to the direct effects of cancer or combined with other comorbidities.^44–48 Factors such as decreased cerebral blood flow, micro embolism related to heart failure, and hypertension may contribute to cognitive decline in both the general population and women diagnosed with breast cancer.^46,47,49,50 While this study did not isolate the specific impact of these comorbidities on dementia onset, our findings indicated that women with breast cancer in Parmer County exhibited a higher likelihood of having cognitive impairment compared to women without breast cancer (OR: 3.8, 95% CI: (1.0, 13.9)). Conversely, many other studies consistently showed findings that are different from ours.^51–55 For instance, a meta-analysis study conducted by Bao et al. showed that out of the 13 studies analyzed, 7 explored the risk of dementia among breast cancer patients and revealed a lower risk (OR: 0.56, 95% CI: 0.27,1.18).⁵²

This study underscored the significance of health insurance and its association with cognitive impairment. In Cochran County, females with health insurance had higher odds of cognitive impairment compared to those without insurance (OR: 1.7, 95% CI: (1.1, 2.7)). One possible explanation is that individuals with insurance may have more frequent interactions with healthcare providers, increasing opportunities for diagnosis of cognitive impairment, whereas those without insurance might have reduced access to diagnostic services.⁵³ These findings indicate that health insurance can play a role in facilitating detection of cognitive impairment and may affect healthcare utilization among women in Cochran County.

Furthermore, females utilizing mental health services within Cochran County exhibited higher odds of having cognitive impairment compared to those who did not use these services (OR^δ: 2.4, 95% CI: (0.7, 8.8)). Access to health insurance is therefore likely to enable earlier diagnosis and better management of cognitive impairment, while those without insurance may only seek care at advanced stages of impairment, when therapeutic interventions are limited.⁵³

We found that neurological factors including memory loss in both males and females across both counties, involuntary movements in females in Cochran County, cerebellar symptoms in females in both counties, as well as gait disorders, specifically, spastic, stiff, narrow gait in males and females in Cochran County, and wide-based, unstable, or shuffling gait in females in Cochran County to be associated with cognitive impairment. These findings are consistent with the report by Espay and Litvan, which discussed the overlapping clinical characteristics found in various causes of cognitive impairment.²⁷ The report indicated that motor and cognitive phenotypes associated with frontotemporal dementia could be understood as existing along a spectrum of clinical, pathological, and genetic disorders, forming a continuum between dementia and parkinsonism. Our findings are also consistent with previous studies that have explored various forms of dementia and determined their association with distinct neurological symptoms.^3,27 For example, memory loss is characteristic of AD, while vascular dementia is often linked to residual sensory and physical deficit, and frontotemporal dementia may present parkinsonism related symptoms like slowed movement, stiffness, and balance issues.^3,27,47

After adjusting for covariates as shown in Table 4, being male and aged 60–69 in Parmer County was associated with cognitive impairment (OR^δ: 41.5, 95% CI: (2.9, 584.2)). These results align with existing literature indicating that advanced age increases the risk of cognitive impairment, and that males may possess lower cognitive reserve compared to females.^33,47 This age group within the male population is predominantly represented among individuals with lower income and limited access to health insurance and healthcare services.⁹ Notably, our analysis found that 50% of males aged 40 and above in Parmer County reported annual incomes below $20,000, a proportion higher than their female counterparts. The combination of these factors, as well as additional cardiovascular, neurovascular, and other chronic disorders identified as dementia risk factors in this age group, may account for these findings.⁷

Memory loss among both male and female residents of Cochran County demonstrated a significant association with cognitive impairment (OR^δ: 10.7, 95% CI: (2.9–38.6)) for males; (OR^δ: 10.9, 95% CI: (1.9–63.9)) for females. Other research confirmed that memory loss is frequently an early sign of AD, the most common type of dementia.³ Other forms, such as vascular, frontotemporal, and Lewy body dementias, also feature memory loss along with other neurological symptoms.^37,47

The males in Cochran County with a bachelor's degree or higher had significantly lower odds of cognitive decline than those without formal education (OR^δ: 0.1, 95% CI: (0.0, 0.9)). These findings on the relationship between education and cognitive impairment are consistent with previous research which concluded that higher education reduces the odds of cognitive impairment.¹² These results also support the cognitive reserve hypothesis, which posits that factors like education, occupation, and lifestyle enhance resilience to cognitive decline.⁵⁵ However, Rusmaully et al. did not find an association between education and neurodegeneration or vascular pathologies.³⁴ Additional research should be conducted to explore the impact of education on cognitive impairment.

Strengths

It is an initial study conducted by using data from Project FRONTIER to analyze sociodemographic, cancer, and neurological disorder variables for Cochran and Parmer Counties in rural West Texas. This study focused on individuals aged 40 and above residing in rural West Texas Counties and was conducted upon receiving approval from the Institutional Review Board (IRB) at TTUHSC, Lubbock, TX-79430. Gender disparities across counties were assessed using proportion tests, and p-values were used to determine the statistical significance. Binary logistic regression was used for bivariate analysis to identify risk factors considering odds ratios and the respective 95% confidence interval. Multivariable logistic regression was subsequently conducted to isolate high-risk factors, adjusting covariates to eliminate confounding effects, and their adjusted odds ratios and respective 95% CI were reported. By focusing on underrepresented rural populations of West Texas, our findings offer valuable insights that not only guide local health interventions but also enhance the broader understanding of AD risk in diverse communities. This study's results will be shared with rural West Texas communities and local Public Health Departments to benefit patients, physicians, students, and public health workers. The results will also be presented at TTUHSC events and national conferences to inform about cognitive impairment risk factors.

Limitations

The study faced some limitations. The results mentioned in this study are limited to people who have access to medical care/insurance, and the analysis is restricted to those participants who were captured in the FRONTIER study. Individuals who had more access to hospital visits may have different characteristics or experiences compared to those who had less accessibility, leading to potential sampling errors. This project used convenience sampling methods that could lead to some bias in the results. Moreover, due to small sample sizes or missing participants, county-specific data for multiple variables were unavailable, which precluded any statistical analysis. The high difference in gender participation within the sample may be attributed to a greater health consciousness among females compared to males. We did not include data on biomarkers, stages of cancer in our study population which would all have contributed to a better understanding of the relationship between cancer and cognitive impairment additionally. This study did not address cancer treatment or the effects of dose reduction or discontinuation, which could influence the efficacy of curative-intent therapies. Decisions regarding dose adjustment or therapy cessation are typically made by health care providers based on individual patient assessments and considerations of treatment efficacy. Project FRONTIER did not collect any longitudinal data from participants.

Conclusions

Various studies have reported mixed outcomes regarding the association between cancer, its treatment, and cognitive impairment; some found an increased risk, while others did not observe differences. In this study, females in Parmer County diagnosed with breast cancer were found to have a significant relationship with cognitive impairment, whereas other cancers did not show statistically significant associations, due to limited data. This research identified notable neurological symptoms associated with cognitive impairment as it relates to AD and other dementias for both males and females in rural West Texas. These findings may serve as an initial contribution for presentation to local rural West Texas communities and health departments, aiming to inform about the prevalence of cognitive impairment and its association with cancer and neurological disorders. Additionally, the study's limitations support the development of further research that will consider the impact of genetic factors, cancer stages and its treatment on the development of cognitive impairment. It remains unclear whether cognitive impairment stems from treatment, the cancer itself, neurological and/or psychological factors. More research using standard tools to assess these factors is needed. Systematic screening for depression, anxiety, and fatigue is crucial, as these can mimic or contribute to cognitive issues. Comprehensive evaluations, including medical history, cancer type and stage, treatment methods, and timing can help distinguish between cognitive changes due to psychological factors and those related directly to cancer or its treatment.^56,57 Collecting and analyzing these data will improve identification of the underlying causes of cognitive deficits.

Footnotes

Acknowledgements

The authors acknowledge the researchers, staff, and participants of Project FRONTIER for their continued data collection and their valuable contribution. The authors would like to thank the Texas Tech University Health Sciences Center for approving the IRB application and allowing access to the database on two rural West Texas counties and providing relevant information that significantly improved the statistical data analysis as well as to present of the findings.

ORCID iDs

Hafiz Khan

Lamourdia Dayamba

Aamrin Rafiq

Ethical considerations

The Texas Tech University Health Sciences Center's Institutional Review Board (TTUHSC IRB) has evaluated and approved the study protocol. Project FRONTIER's approval date was January 30, 2006, and the IRB number was L06–028. The Julia Jones Matthews School of Population and Public Health's Department of Public Health as well as its other schools within TTUHSC rigorously adheres to the highest ethical standards.

Consent to participate

This study used deidentified data from participants who consented to Project FRONTIER during data collection.

Consent for publication

Not applicable.

Author contribution(s)

Hafiz Khan: Conceptualization; Data curation; Methodology; Statistical analysis; Supervision; Writing – original draft; Writing – review & editing.

Lamourdia Dayamba: Data curation; Statistical analysis; Writing – original draft; Writing – review & editing.

Aamrin Rafiq: Data curation; Statistical analysis; Writing – original draft; Writing – review & editing.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Data availability statement

It would be enlightened to the readers that the data supporting the findings of this study may not be available upon request as the institution strictly follows high ethical standards and is committed to maintaining the confidentiality of participants’ information. We appreciate their understanding and respect for the ethical guidelines of the institution.

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