Assessment of Predictive Response Factors to Intragastric Balloon Therapy for the Treatment of Obesity

Abstract

Background:

Obesity is a worldwide epidemic that is difficult to control with non-invasive treatments, which usually present poor results. In this context, the intragastric balloon (IGB) is an important tool that presents a mean body weight loss (BWL) estimated at approximately 12%, although individual responses are highly variable.

Objectives:

This study assesses whether there are factors that can predict responses to IGB therapy either before or early after placement of the device.

Materials and Methods:

A total of 50 obese patients underwent insertion of IGB placed endoscopically, and patients were monitored for 6 months. The evaluated predictive factors involved general characteristics and psychological, social, and dyspeptic aspects, and the preliminary results obtained in the first month after balloon placement.

Results:

The mean weight loss was 11.5%, and 48% of the participants presented BWL >10%. Among the factors analyzed before IGB placement, only advanced age (P = .04) and higher scores obtained in the social relationships domain of a shorter version of the World Health Organization's Quality of Life questionnaire (P = .02) were significant. Analysis of the factors evaluated after IGB placement revealed that the BWL amounts observed in week 2 (P = .001) and week 4 (P < .001) and the intensity of dyspeptic symptoms in week 2 (P < .001) were positive predictive factors.

Conclusions:

The assessment of predictive factors may help to manage patients with IGB.

Introduction

Obesity is a chronic disease that has reached epidemic proportions. Its incidence has been increasing in most countries, especially in the past 20 years.^1,2 This disease is a public health problem of great importance, with an estimated 30% increase in overall mortality for each 5 kg/m² increase in body mass index (BMI) >25 kg/m².³ Additionally, there are several comorbidities associated with obesity, ranging from cardiovascular diseases to neoplastic disorders, which lead to decreased productivity and quality of life of patients.⁴

Obesity treatment is complex and multidisciplinary and has been considered a major challenge in clinical practice. Pharmacological and behavioral treatments present limited efficacy and durability.⁵ Although effective, bariatric surgery presents major adverse event rates up to 25% and mortality rates up to 2%.^6,7 In this context, intragastric balloon (IGB) therapy is an option for obesity treatment because it is a minimally invasive, effective, and reversible procedure. This device acts by inducing satiety while reducing gastric capacity, resulting in reduced food intake.⁸ A meta-analysis showed a mean body weight loss (BWL) of 12.2%, a BMI loss of 5.7 kg/m², and excess BWL of 32% after 6 months of IGB use.⁹

Despite good outcomes for the IGB observed in a group of patients, the responses are highly variable between individuals. A recent study revealed that 17% of patients did not achieve the minimum stipulated loss of 20% of excess body weight.¹⁰ The success of IGB therapy depends on multiple factors, including personal motivation, behavior, and social support.

This study aimed to assess several factors that could predict responses to IGB before its placement and in the first month of its use. The evaluated predictive factors involve general characteristics and psychological, social, and dyspeptic aspects and the preliminary results obtained in the first month after balloon placement.

Materials and Methods

Subjects

Fifty obese (BMI ≥30 kg/m²), nondiabetic individuals with metabolic syndrome treated in the State Institute of Diabetes and Endocrinology of Rio de Janeiro were evaluated in this longitudinal study. The number of participants was set for convenience. All patients were <50 years of age, and all women presented regular menstrual cycles. The presence of metabolic syndrome was defined according to the International Diabetes Federation,¹¹ with one mandatory criterion (waist circumference >90 cm for men and >80 cm for women) and at least two of the following criteria: (1) triglyceride levels ≥150 mg/dL (or use of a specific treatment to reduce triglyceride levels); (2) high-density lipoprotein (HDL) <40 mg/dL in men and <50 mg/dL in women (or use of a specific treatment for HDL); (3) systolic blood pressure ≥130 mmHg and diastolic blood pressure ≥85 mmHg (or use of a specific treatment for high blood pressure); and (4) fasting glucose levels ≥100 mg/dL.

The exclusion criteria included diagnosis of type 1 or type 2 diabetes mellitus, pregnancy or a plan to become pregnant in the next 6 months, previous gastric surgery, hiatal hernia ≥5 cm, coagulation disorders, lesion in the upper digestive tract with potential for bleeding, alcoholism or drug use, or advanced liver disease.

The study protocol was approved by the Institutional Research Ethics Committee, and all participants signed a consent form that was prepared in accordance with the Declaration of Helsinki. The study is registered at ClinicalTrials.gov (Identifier: NCT01598233).

Methods

The silicon IGB (Silimed, Rio de Janeiro, Brazil) was placed endoscopically in patients deeply sedated with propofol, midazolam, and meperidine. Under endoscopic visualization, the IGB was positioned in the gastric fundus and was filled with 650 mL of saline (0.9% NaCl) and 20 mL of methylene blue. Immediately after the procedure, all patients received intravenous administration of ondansetron and omeprazole. Oral ondansetron was regularly administered for 1 week and omeprazole throughout the entire period that the balloon was placed in the patient's stomach. All patients were discharged within a maximum of 12 hours, with most of them being discharged within the first 6 hours.

Patients received a liquid diet in the first week after IGB placement, followed by a week of pureed diet. After 2 weeks, patients were instructed to maintain a diet of 1200 kcal/day. Except for the cases where an earlier removal was required, the IGB was removed endoscopically after 6 months with the patients under deep sedation.

Patients were monitored before IGB placement and during frequent medical visits that occurred at weeks 1, 2, 4, 8, 16, and 24 after the procedure. Anthropometric measurements were assessed at each visit and included body weight (in kilograms), BMI (calculated by body weight divided by height squared, expressed in kg/m²), waist circumference (measured at half of the distance between the iliac crest and costal margin, expressed in centimeters) and waist–hip ratio (hip circumference measured at the widest point around the greater trochanter). The success of BWL was defined as >10% until the removal of the IGB. The desire for the treatment was considered for the analysis of the results.

Dyspepsia (indigestion) symptoms were assessed before and 1 and 2 weeks after IGB placement with the Porto Alegre Dyspeptic Symptoms Questionnaire (PADYQ). This instrument was developed by a Brazilian group and has been validated.¹² The scores range from 0 to 44, where a patient with a score >7 is considered to have dyspepsia.

Symptoms of anxiety and depression were assessed with the Hospital Anxiety and Depression Scale, which was completed by the patient before IGB placement.¹³ This scale excludes somatic symptoms and consists of 14 questions: seven assess anxiety, and seven assess depression. Each item can be scored from 0 to 3, and the maximum score on the scale is 21. The Beck Depression Inventory was also used to measure the severity of depression symptoms. It consists of 21 questions, each with four choices corresponding to increasing levels of intensity of depression.¹⁴ Both scales have been translated and validated in Brazil.

Quality of life was assessed before the procedure using a shorter version of the World Health Organization's Quality of Life (WHOQOL-bref) questionnaire, which is a simplified psychometric instrument created by the World Health Organization (WHO) from the original version (WHOQOL-100) to assess quality of life. This questionnaire is a self-explanatory instrument and addresses how individuals rate their quality of life, status of health, and other aspects of their lives. This tool consists of 26 questions. Two are general questions, and the other 24 are related to four domains: physical health, psychological health, social relationships, and environment. Each domain of the instrument identifies a specific focus of attention for the individual's quality of life. The WHOQOL-bref has been translated and validated for the Portuguese.¹⁵ The results range from 1 to 5 and have the following meanings: needs improvement (1 to 2.9), average (3 to 3.9), good (4 to 4.9), and very good (5).

Among the eating disorders, binge eating disorder was specifically analyzed in this study. Binge eating severity was assessed with the Portuguese version of the Binge Eating Scale.¹⁶

Statistical analysis

Analyses were performed using IBM SPSS Statistics for Macintosh v20.0 (IBM Corp., Armonk, NY). In the descriptive analysis, categorical variables are expressed as percentages and their frequencies, and numerical variables are expressed as means ± standard deviations (SD). The Kolmogorov–Smirnov test indicated that all numeric variables were normally distributed. A parametric t-test was used to compare numerical variables between groups. The Spearman correlation coefficient was used to study the correlations between numerical variables. The chi-square or Fisher exact tests were used to evaluate categorical variables. For the model of binary logistic regression, the Nagelkerke coefficient of determination was used. A P value of <.05 was considered statistically significant.

Results

The study population consisted of 40 women and 10 men. The general characteristics of the individuals before IGB placement are shown in Table 1. The distribution of the participants according to their BMIs was as follows: 12 participants were classified as obese class I (BMI = 30–34.9 kg/m²), 16 were classified as obese class II (BMI = 35–35.9 kg/m²), and 22 were classified as obese class III (BMI >40 kg/m²). All patients were sedentary and were instructed on a diet of 1200 kcal/day. None of the participants were smokers or consumed >20 g of alcohol per day.

Table 1.

General Data

General information
Age (years)	34.6 ± 7.0
Ethnicity (Caucasian/non-Caucasian)	17/33
Sex (male/female)	10/40
Body mass index (kg/m²)	40.08 ± 6.3
Waist circumference (cm):
Male	124 ± 13.1
Female	112 ± 16.3
Waist/hip ratio	0.90 ± 0.07
Psychological disorders
Anxiety (HADS)	22 (44%)
Depression (HADS)	19 (38%)
Depression (Beck)	14 (28%)
Binge eating	16 (32%)
PADYQ
Dyspepsia	21 (42%)
Quality of life (WHOQOL-bref)
Global	2.67 ± 0.93
Physical health	3.13 ± 0.72
Psychological health	3.22 ± 0.69
Social relationships	3.40 ± 0.73
Environment	3.01 ± 0.53

HADS, Hospital Anxiety and Depression Scale; PADYQ, The Porto Alegre Dyspeptic Symptoms Questionnaire; WHOQOL-bref, shorter version of the World Health Organization's Quality of Life questionnaire.

Forty of the total participants kept the IGB for 6 months. Among the participants who had an early removal of the device, four had it removed due to intolerance to the device, four because of balloon rupture, one due to the diagnosis of cervical neoplasia that required a surgical procedure, and one due to the occurrence of gaseous balloon distension.¹⁷ Only one patient had the IGB placed for <1 month (the device was removed in the first week). On average, the IGB was placed for 85 days among the patients who had early removal of the device.

The mean BWL was 11.5% ± 8.22%. Twenty-four patients (48%) lost >10% of their body weight, which was considered as successful therapy. Among those patients who achieved success, seven (29%) lost >20% of their initial body weight. However, 11 patients (22%) lost <5% of their body weight, and 15 (30%) lost between 5% and 9.9% of their body weight.

The evaluation of the predictive factors before IGB placement revealed that age (P = .04) and the social relationships domain of the WHOQOL-bref (P = .02) were the only important factors to predict BWL >10% with this device. The analysis of the groups based on the achievement of the final goal revealed that older patients (mean age 36.8 ± 6.72 versus 32.8 ± 6.95 years) and patients with stronger social relationships (mean 3.64 ± 0.59 versus 3.17 ± 0.79 score) presented higher rates of success. There was no difference in baseline BMI between patients who achieved BWL >10% (mean BMI: 41.24 ± 6.31 kg/m²) and those who had not (mean BMI: 39.18 ± 6.29 kg/m²). Patients with BWL >10% also presented a trend (P = .09) toward higher scores in the Binge Eating Scale (17.1 ± 7.33 versus 12.6 ± 7.05 points).

The evaluation of percentage of BWL revealed that the social relationships domain of the WHOQOL-bref was the only domain that reached statistical significance (r = 0.311; P = .03). There was a trend (P = .07) toward greater BWL in women (mean: 12.5% ± 8.38%) compared with that in men (7.31% ± 6.27%). There was no difference in mean BMI between sexes (40.3 ± 6.74 kg/m² for women and 39.3 ± 4.28 kg/m²for men).

There was no significant association of the factors assessed before IGB placement and early removal with the presence of depression assessed by the Beck criteria; only a trend was apparent (P = .08).

Tables 2 and 3 show the predictive factors after IGB placement that reached significance (P < .10) for BWL >10% and for device removal, respectively. A BWL >5% observed at week 4 was also correlated with BWL >10% at the end of the study period (P = .04). Among the 41 patients who lost >5% of their body weight in the first month, 56% had achieved BWL >10% when the device was removed. Among the eight who lost <5% of their body weight in the first month, seven (87%) did not achieve success.

Table 2.

Relationship Between Predictors After Intragastric Balloon Placement and Weight Loss >10%

	Weight loss
Predictors	<10%	>10%	P value
Weight loss at week 1	3.63% ± 1.46%	4.37% ± 1.29%	.067
Weight loss at week 2	3.93% ± 1.39%	5.60% ± 1.98%	.001
Weight loss at week 4	5.44% ± 1.86%	7.82% ± 2.23%	<.001
PADYQ nausea at week 2 (score)	3.04% ± 3.70%	5.64 ± 4.54	.036
PADYQ vomit at week 2 (score)	1.04 ± 1.42	2.18 ± 1.46	.010
PADYQ total at week 2 (score)	17.24 ± 8.75	24.09 ± 10.44	<.001

Statistically significant values shown in bold.

Table 3.

Relationship Between Predictors After Intragastric Balloon Placement and Early Withdrawal

	Early withdrawal
Predictors	No	Yes	P value
Weight loss at week 1	3.84% ± 1.41%	4.74% ± 1.22%	.073
Weight loss at week 2	4.49% ± 1.79%	5.90% ± 1.94%	.042
Weight loss at week 4	6.32% ± 2.36%	7.86% ± 2.04%	.077
PADYQ vomit at week 1 (score)	2.28 ± 0.82	3.25 ± 0.88	.005
PADYQ satiety at week 1 (score)	3.67 ± 0.88	4.00 ± 0.77	.017

The percent of BWL was correlated with the following predictive factors after IGB placement: BWL at week 1(r = 0.304; P = .03), BWL at week 2 (r = 0.516; P < .001), BWL at week 4 (r = 0.694; P < .001), nausea at week 2 (r = 0.393; P = .006), vomiting at week 2 (r = 0.455; P = .001), and total dyspepsia score (r = 0.380; P = .008). Patients who achieved BWL >5% at week 4 reached a percent of BWL greater than those who did not obtain the index (12.8% ± 7.73% versus 4.5% ± 7.48%; P = .008).

A binary logistic regression analysis was performed to create a model to explain the factors involved in BWL >10% (Table 4). Therefore, the independent variables that were statistically significant in the univariate analysis were used (BWL at weeks 1, 2, and 4; PADYQ vomiting; PADYQ pain; and PADYQ nausea at week 2). Taking into account the six independent variables simultaneously, the model was statistically significant in predicting BWL >10% (χ² = 21.80; df = 6; N = 47; R² Nagelkerke = 0.50; P = .007). These findings indicate that approximately 50% of the variance in whether patients experienced BWL >10% can be predicted from the linear combination of these six independent variables. Table 4 gives the odds ratios for each variable. These results indicate that the odds of having BWL >10% increase approximately 100% for each unit increase in BWL at week 4 (odds ratio [OR] 2.039; 95% confidence interval 1.089–3.816; P = .026).

Table 4.

Binary Logistic Regression Analysis to Predict Weight Loss >10%

Variables	β	Odds ratio	95% CI	P value
Weight loss at week 1	−0.49	0.613	0.266–1.411	.249
Weight loss at week 2	0.31	1.363	0.625– 2.971	.436
Weight loss at week 4	0.71	2.039	1.089–3.816	.026
PADYQ vomit at week2	0.53	1.702	0.821–3.53	.153
PADYQ pain at week 2	0.24	1.271	0.983–1.644	.068
PADYQ nausea at week 2	−0.18	0.835	0.623–1.119	.227
Constant	−5.4	0.005		.003

β, regression coefficient; CI, confidence interval.

Discussion

Based on the information available in the literature, this clinical trial is the most comprehensive prospective study that evaluated the capacity of individual factors to predict responses to IGB therapy. Several factors in different fields were assessed both before and during the first month after the device placement, encompassing physical and psychological aspects.

The mean BWL observed in this study was 11.5%, which is consistent with findings obtained in a previous IGB meta-analysis (12.2%).⁹ The variability of individual response reflects results observed in clinical practice, with 29% of patients presenting >20% weight loss and 22% presenting <5% weight loss. The early removal rate was higher than expected (20% of patients) compared with the rate reported in a previous meta-analysis (4.2%).⁹ Some factors may explain this discrepancy: (1) the volume of liquid was near the maximum capacity of the balloon (670 mL), which increases intolerance and causes greater tension in the wall of the device; (2) a different IGB brand was used; and (3) the patients were of lower socioeconomic status with lower social support, and might have been unable to rest properly in cases of intolerance. To reduce the impact on the study, the intention to treat was used in the analysis. The mean period of time that the IGB remained in the stomachs of the patients who had early removal should also be emphasized (85 days). This time is an important fact to be considered because most of the BWL occurs during the first months after the procedure.¹⁸

The study revealed an important relationship between BWL in the first weeks (weeks 1, 2, and 4) and positive outcomes of the IGB therapy (BWL >10%) that, after the multivariate analysis, was significant only in week 4. This finding is consistent with a previous observation that demonstrated that the stomach adapts to the balloon and that this early period is very important for the final BWL.¹⁹ In a study with 50 patients, Dogan et al.²⁰ showed that a BWL >5% in the first month would predict BWL >10% in 6 months in 96% of cases. In cases of BWL <5% in the first month, only 15% achieved BWL >10% at the end of the study. In the current study, the positive predictive value of BWL >5% was considerably lower (56%), but the negative predictive value was similar (12%), reinforcing the finding that the unsatisfactory BWL in the first month should be considered a predictor for poor treatment outcome.

Another interesting finding was the presence of dyspeptic symptoms in week 2 predicting the final response to IGB treatment. The presence of dyspeptic symptoms in the first week²¹ of treatment was almost universal. Therefore, that symptom was not a predictive factor in the present study. However, the presence of dyspeptic symptoms in the second week demonstrates poorer adaptation of the stomach to the balloon, with its effect maintained in terms of satiety.

In a recent retrospective study, Kotzampassi et al.²² reported the following as the most powerful determinants of weight loss >50% of excess body weight: advanced age, female sex, higher educational level, and being single or divorced (marital status). In the present study, age was significantly correlated with BWL >10%, and female sex showed a trend when correlated with percent of BWL, thus corroborating the retrospective study. This finding most likely reflects the profiles of those patients who are more concerned with their body image and health compared with those who are younger and male patients. The relationship between BWL and social support observed in the present study is in agreement with this profile of greater concern about body image.

Psychological disorders (anxiety, depression, and binge eating) were evaluated, and only a trend toward a higher score in the Binge Eating Scale was noted in patients who achieved BWL >10%. This result is not in agreement with an Italian study conducted in 2007²³ that evaluated the effects of binge eating disorder on IGB treatment outcomes in morbidly obese individuals. In this study, patients with this disorder presented a modest reduction in BMI, a higher rate of adverse events, and failure to lose 10% of their body weight. Several studies have evaluated bariatric surgery outcomes based on the state of anxiety and depression before surgery; the results vary from a lack of any relationship to both positive and negative impacts.^24–28 The only study that investigated IGB showed no significant difference in BWL at the end of 6 months between the groups with and without depression,²⁹ which is similar to the results of the current study.

The prediction for early removal was also evaluated. Signs of intolerance (vomiting and satiety in the first week and BWL in the second week) showed statistical significance. The presence of depression, as measured by the Beck Depression Inventory, tended to predict early removal, a trend that could reach significance if the group were larger. There are no data available in the literature to be compared with these data.

The strength of this study is the comprehensive evaluation of several factors related to IGB treatment that present significant and consistent results. However, the study presents some limitations. First, the sample size consisted of 50 patients and evaluated a relatively large number of predictive response factors. Second, the rate of early removal was higher compared with the average reported in the literature, as previously discussed. Third, there was a small number of males in the sample, although the relative group sizes reflect the demand in the real world.

In conclusion, the IGB is a useful tool for treating obesity. Investigations of factors that may predict responses to IGB therapy are crucial to optimize not only its indications but also its outcomes. The data obtained can indicate several methods to achieve this goal, among which the most evident is the need for additional therapies (i.e., pharmacological, psychological, and physical activity) in cases of unsatisfactory BWL in the first month. Broader prospective studies may corroborate the data found in the current study.

Footnotes

Acknowledgment

Intragastric balloons were donated by the company Silimed (Rio de Janeiro, Brazil).

Disclosure Statement

No competing financial interests exist.

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