The Impact of Preoperative Body Weight on Quality of Life after Surgical Treatment for Morbid Obesity

Abstract

Introduction and Purpose:

Although the effect of bariatric treatment on quality of life has already been unambiguously confirmed, many of its aspects have not yet been fully studied. A study was planned to analyze an effect of surgical treatment for obesity with the laparoscopic sleeve gastrectomy (LSG) or the laparoscopic gastric bypass on quality of life of treated patients, depending on the obesity stage on qualification for bariatric treatment.

Material and Methods:

The studied group consisted of 130 patients treated for super obesity. Overall, 68 (52%) patients underwent LSG, and the remaining group of 62 (48%) patients underwent laparoscopic Roux-en-Y gastric bypass. In the whole studied group, the mean body mass index (BMI) value was 50.44 kg/m². The studied group of patients was divided into two subgroups: with initial BMI of <50 kg/m² (morbid obesity) and of >50 kg/m² (super obesity). In both groups, quality of life was assessed by using the SF-36 questionnaire both before initiation of treatment and 1 year after the surgery.

Results and Conclusion:

The recorded quality of life was very poor in all patients, regardless of the initial BMI value. The surgical treatment resulted in a significant reduction in body mass. The mean excessive BMI loss (%EBMIL) was 68.05%. The surgical treatment resulted in a significant improvement in all quality-of-life parameters. No significant relationship was found between the improvement in quality of life and initial BMI or the type of surgery.

Introduction

The number of patients suffering from super obesity increases continuously all over the world, including Poland. The body mass index (BMI) ≥40 or >35 kg/m² with comorbidities was defined as morbid obesity, and more than 50 kg/m² was defined as super obesity. The society and doctors of all specialities alike know very well the consequences of excessive body mass to our health, including a risk of premature death. Numerous chronic obesity-related health problems have been defined and well known, and nowadays they are considered to be its evident complications.^1,2

A relationship between obesity and poor quality of life, although seemingly obvious, is commonly omitted. Numerous reports are available for studying the effects of bariatric procedures on body mass reduction and obesity-related diseases, and surgery is considered the most optimal form of treatment for patients with the most severe forms of obesity.^3–7 Nevertheless, the effect of bariatric treatment on quality of life, though it seems unambiguous, still has not been studied in full; whereas no clear answers have been found to numerous clinical problems on the basis of conducted studies.^8,9

A study was planned to analyze an effect of surgical treatment for obesity with the laparoscopic sleeve gastrectomy (LSG) or the laparoscopic gastric bypass on quality of life of treated patients, depending on the obesity stage at the moment of qualification for bariatric treatment.

Aim of the Article

Evaluation of the effect of the initial body mass on quality of life of patients treated for obesity with the LSG or the laparoscopic gastric bypass.

Methods

The study was initiated by following the consent of the Ethics Committee, Jagiellonian University. A prospective analysis was conducted in a group of patients who were operated for super obesity at the 2'nd Departament of Surgery of Jagiellonian University Medical College, who gave their informed consent for participation in the study after being thoroughly acquainted with the study assumptions and objectives.

Into the study group we enrolled patients between 18 and 65 years with morbid and super obesity meeting qualification criteria for a bariatric surgery developed by the Metabolic and Bariatric Surgery Section of the Polish Surgical Society, that is, BMI exceeding 40 kg/m², BMI exceeding 35 kg/m² when obesity-related diseases are diagnosed, including type 2 diabetes, hypertension, lipid disorders, and obstructive sleep apnea who were subjected to LSG or laparoscopic Roux-en-Y gastric bypass (LRYGB) and had written consent to participate in the study. The patients who underwent a revision surgery, had suffered for postoperative or delayed surgical complications, did not report to a follow-up visit 12 months after the surgery, and who were diagnosed with alcohol or drug dependence were excluded from the study group. Apart from these were the patients who were diagnosed with nonstabilized psychotic disorders, severe depression, and personality and eating disorders.

Before the surgery, patients who qualified for the study were initially evaluated. A detailed medical interview and physical examinations were conducted, and the initial body weight was determined by using the Tanita BC-420S MA apparatus. On the basis of obtained results, the studied group of patients was divided into two subgroups: with an initial BMI of <50 kg/m² (morbid obesity) and of >50 kg/m² (super obesity). Initial quality of life was assessed in both groups before treatment onset.

In each group, some patients underwent the LSG and the remaining patients underwent the LRYGB. A decision about the surgery type was based on the preference of a patient and a doctor in charge.

Twelve months after the surgical treatment, a follow-up examination was performed regarding initially evaluated anthropometric parameters and quality of life. Obtained results were analyzed statistically.

Quality-of-life assessment

To assess quality of life of patients operated at the 2'nd Departament of Surgery of Jagiellonian University Medical College, the Short Form Health Survey (SF-36) form validated for the Polish population was used, under a purchased licence. The Polish version of SF-36 questionnaire is designed to assess subjective health. It consists of 11 questions containing 36 statements that allow to describe eight elements of QOL: physical functioning (PF), role limitations due to physical health problems (RP), bodily pain (BP), general health perceptions (GH), vitality (VT), social functioning (SF), role limitations due to emotional problems (RE), and general mental health (MH). Indicators can be summed up in two scales: PCS—Physical Component Summary, MCS—Mental Component Summary. In addition, when we summed all scores from eight parts of the questionnaire, we can calculate the index of quality of life in the global dimension (maximum 170 scores). Before the surgery, parameters corresponding to eight quality-of-life spheres were assessed on a basis of the SF-36 form.¹⁰

Statistical analysis

In the statistical analysis conducted in STATISTICA 10 PL, the Shapiro–Wilk test was applied to check for normal distribution. The results are presented as mean ± standard deviation. In case of normal distribution, t-Student test was used. In case of non-normal distribution, we employed the nonparametric Mann–Whitney test. The effects for which the probability value p was lower than the adapted level of significance α = 0.05 (p < 0.05) were assumed to be significant.

Material

In the period from January 2013 to January 2014, 130 patients were treated for super obesity at the 2'nd Departament of Surgery of Jagiellonian University Medical College, who gave their consent to participation in the study. The group consisted of 78 women, of a mean age of 43.2 years, and of 52 men, of a mean age of 42.6 years. The mean age in the whole group was 42.9 years. Before the surgery, the mean body weight was 147.5 kg (ranging from 112 to 196 kg), and the mean BMI value was 50.44 kg/m² (ranging from 39.7 to 71.13 kg/m²). The BMI did not exceed 50 kg/m² in 72 (55%) patients (40 women, 32 men). The presurgery body weight exceeding BMI of 50 kg/m² was found in the remaining 58 (45%) patients (38 women, 20 men).

In the group of 130 patients who qualified for surgical treatment, LSG was performed in 68 (52%) patients, and LRYGB was performed in the remaining 62 (48%) patients. In the group of all patients who qualified for the surgery, 94 (72%) people were diagnosed with hypertension requiring pharmacological treatment, and 61 (47%) of participants had type 2 diabetes before the operation (Table 1).

Table 1.

Participants' Characteristics at Baseline

	BMI <50 kg/m² (n = 72)		BMI >50 kg/m² (n = 58)
Type of surgery	LSG (n = 40)	LRYGB (n = 32)	LSG (n = 28)	LRYGB (n = 30)
Age	40.5 (19–63)	41.5 (25–59)	41.7 (23–62)	41.2 (25–58)
Female (n)	24	16	20	18
Male (n)	16	16	8	12
Mean weight before surgery (kg ± SD)	134 ± 17.9	132 ± 17.7	161 ± 22.3	162 ± 21.6
Mean BMI before surgery (kg/m² ± SD)	44.7 ± 2.9	44.5 ± 2.8	57.3 ± 4.8	57 ± 5.1
Hypertension before surgery (n)	20	26	19	29
Type 2 diabetes before surgery (n)	8	15	11	27

BMI, body mass index; LRYGB, laparoscopic Roux-en-Y gastric bypass; LSG, laparoscopic sleeve gastrectomy; SD, standard deviation.

Results

Results of bariatric treatment

In all patients, surgical treatment resulted in a significant reduction in body mass. The mean postsurgery BMI was 30.29 kg/m² in the group of patients with a lower initial BMI of <50 kg/m², and it was 37.6 kg/m² in the group of patients with an initial BMI of >50 kg/m² (p = 0.023) (Fig. 1).

FIG. 1.

Reduction in body weight after surgery depending on the starting mean BMI. BMI, body mass index.

The mean percentage weight loss (%WL) was 33.4%; 32% and 34.8% in groups with an initial BMI of <50 kg/m² and of >50 kg/m², respectively (p = 0.38). An estimated mean excessive BMI loss (%EBMIL) was 68.05% for the whole studied group. In the group with lower initial body weight, the mean%EBMIL was estimated as 73.85%, and in the group with higher initial body weight the mean%EBMIL was 62% (p = 0.0085). In the groups with BMI <50 kg/m² and with BMI >50 kg/m² alike, no statistically significant differences were noted for postoperative body weight loss depending on the type of surgery (Table 2).

Table 2.

Weight Loss After Surgery

	BMI <50 kg/m² (n = 72)		BMI >50 kg/m² (n = 58)
Type of surgery	LSG (n = 40)	LRYGB (n = 32)	LSG (n = 28)	LRYGB (n = 30)
Mean weight before surgery (kg ± SD)	134 ± 17.9	132 ± 17.7	161 ± 22.3	162 ± 21.6
Mean weight after surgery (kg ± SD)	90 ± 13.5	91 ± 15	105.3 ± 20.1	106 ± 22.1
Mean BMI before surgery (kg/m² ± SD)	44.7 ± 2.9	44.5 ± 2.8	57.3 ± 4.8	57 ± 5.1
Mean BMI after surgery (kg/m² ± SD)	30.29 ± 3.4	30.33 ± 4.1	37.6 ± 5.2	36.8 ± 5.3
%WL (% ± SD)	32.2 ± 5.9	31.9 ± 6	34.8 ± 7.4	34.3 ± 8.2
%EWL (% ± SD)	61.9 ± 12.5	61.4 ± 14.5	55 ± 12.1	54.3 ± 12.7
%EBMIL (% ± SD)	74.1 ± 14.4	73.6 ± 17	62.3 ± 13.9	61.5 ± 15.2

EBMIL, excessive body mass index loss; EWL, excessive weight loss; WL, weight loss.

In both groups of treated patients, a significant improvement was observed for obesity-related diseases. The number of people requiring treatment for hypertension and for type 2 diabetes decreased. After the surgery, in the group of patients with BMI <50 kg/m², 12 (16%) patients required treatment for hypertension, and 6 (8%) patients required treatment for type 2 diabetes. In the group of patients with BMI <50 kg/m², hypertension was found in 17 (29%) patients and type 2 diabetes was observed in 22 (37%) patients at a follow-up visit. The percentage of patients not requiring further treatment for diabetes and hypertension after the surgery was lower in a group of patients with a higher initial BMI, than in those with a lower initial BMI (p = 0.021).

Pre- and postsurgery quality-of-life assessment

Presurgery quality of life was significantly lower in all studied patients, regardless of the initial BMI value. In the whole studied group, the mean value of an index describing the total quality of life was 85.5. The total quality of life index was 86 points in the group of patients with BMI <50 kg/m² and 85 points in the group of patients with BMI >50 kg/m². No statistically significant difference was noted between groups for preoperative quality of life for any of the analyzed parameters. Similarly, in both groups, no statistically significant differences were found for initial quality of life depending on qualification for relevant surgeries (Table 3).

Table 3.

Summary of Results for the SF-36 Questionnaire Obtained Before and After Surgery

Quality of life	BMI <50 kg/m² (mean value ± SD)	BMI >50 kg/m² (mean value ± SD)	p
Physical function
Before surgery	36.7 ± 10.5	36.6 ± 10.9	0.066
After surgery	53.5 ± 7.1	53.61 ± 7.4	0.402
Role physical
Before surgery	35.7 ± 14.6	36.4 ± 14.6	0.41
After surgery	52.4 ± 11.1	52 ± 11.4	0.39
Body pain
Before surgery	45.1 ± 11.9	45.5 ± 12	0.24
After surgery	56 ± 8.7	56.4 ± 8.3	0.15
General health
Before surgery	38.5 ± 8.1	39.1 ± 8	0.107
After surgery	52.5 ± 7.2	52.4 ± 7.7	0.44
Vitality
Before surgery	45.47 ± 7.4	45.7 ± 7.5	0.52
After surgery	55.5 ± 5.8	55.6 ± 6	0.07
Social function
Before surgery	43.07 ± 8.4	43.3 ± 8.6	0.42
After surgery	51.7 ± 5.3	51.74 ± 5.4	0.3
Role emotional
Before surgery	36.29 ± 18.8	36.26 ± 19.2	0.38
After surgery	51.08 ± 12.4	51.12 ± 12.4	0.46
Menthal health
Before surgery	41.8 ± 7.3	42.2 ± 7.4	0.37
After surgery	49.6 ± 7	49.7 ± 7.2	0.46
Global quality of life
Before surgery	86 ± 49	84 ± 46	0.42
After surgery	147 ± 35	143 ± 33	0.36
P	0.0012	0.0011
Global quality of life–physical health
Before surgery	39.78 ± 9.2	39.31 ± 9.2	0.23
After surgery	54.8 ± 7.2	54.9 ± 7.4	0.13
p	0.0011	0.0025
Global quality of life–mental health
Before surgery	42.61 ± 10.1	42.8 ± 10.4	0.077
After surgery	50.3 ± 7.4	50.4 ± 7.5	0.23
p	0.0017	0.0038

An analysis of individual components of the SF-36 questionnaire (PF, RP, BP, GH, VT, SF, RE, MH) indicated a statistically significant improvement in quality of life for all studied parameters. A mean total quality-of-life index in the whole group was 144.5 points, representing an increase by 59 points versus the initial value (85.5 points). The postoperative total quality-of-life index was 147 points in the group of patients with BMI <50 kg/m² and 143 points in the group of patients with BMI >50 kg/m² (Fig. 2).

FIG. 2.

Mean value of global quality of life after surgery depending on baseline BMI.

Postsurgery quality of life in terms of physical health (PSC) was 54.8 points in the group with initial BMI <50 kg/m² and 54.9 points in the other group. For a parameter describing quality of life in terms of mental health (MSC), 1 year after surgery, its value reached 50.3 points for people with a lower initial BMI, and 50.4 points in the group of patients with an initial BMI >50 kg/m². No statistically significant differences were noted for any studied component of quality of life between the groups with initial BMI <50 kg/m² and those with initial BMI >50 kg/m² (Table 3).

In the groups with BMI <50 kg/m² and with BMI >50 kg/m² alike, no statistically significant differences were noted for improvement in quality of life in relation to a type of surgery.

Discussion

According to a current definition proposed by WHO, health is not merely the absence of disease, but a state of complete physical, mental, and social well-being. According to the modern concept, the sense of complete health is a basic indicator for a good quality of life. Currently, most authors agree that obesity, by deteriorating a sense of health, negatively affects quality of life.^11,12

A continuous increase in a number of obese people throughout the world is accompanied by a steady rise in a number of bariatric surgeries.⁴ The increasing number of authors notices a positive effect of surgical treatment for obesity not only in form of weight loss and improvement in chronic obesity complications but also in quality of life of treated people. Although new studies on quality of life of patients after bariatric treatment are published, still many clinical questions remain unanswered. One of them is a question regarding the effect of the initial body weight on a degree of improvement in quality of life of patients surgically treated for super obesity. Is it possible for a patient with an extremely high BMI to achieve an improvement in quality of life resulting from applied treatment comparable to that observed in a patient at a lower range of criteria qualifying for surgery?

To assess quality of life in patients treated surgically for super obesity in this study, the Short Form Health Survey (SF-36) consisting of 36 simple questions was selected from other available tools. This is one of the most commonly used tools for health-related quality of life assessment, has a Polish language version, and is also accompanied by a set of tables with standards validated for the Polish population.¹³

An analysis of initial presurgery results obtained during the study using the SF-36 questionnaire in patients treated at the 2nd Department of Surgery of Jagiellonian University Medical College demonstrated a significantly reduced quality of life in the whole group. All of the studied quality-of-life components evaluated on the basis of answers given to questions included in the questionnaire achieved significantly lower values than the standard values for the Polish population. Similarly, very low values of studied parameters of the initial quality of life in a group of patients who qualified for bariatric treatment were also reported in the works of Serwer and Martina de Zwaan.^14,15 What is interesting, in our study, is that the initial quality of life of patients with BMI <50 kg/m² (morbid obesity) was comparable to the initial quality of life of patients with BMI >50 kg/m² (super obesity). Although the percentage of patients with hypertension and type 2 diabetes was higher in the group with a higher initial BMI, it did not influence the degree of quality-of-life deterioration, although such a relationship could have been suspected.

At a follow-up visit 1 year after the surgery, the satisfying bariatric effect was achieved for all patients, with BMI <50 kg/m² and BMI >50 kg/m² alike, comparable to reports of other authors. In both groups, no statistically significant differences were found for the extent of body weight loss depending on the type of the surgery.^13,16–18

One year after the surgery, significant improvement was noted for quality of life of treated patients. The improvement was observed for the total quality of life, its physical (PCS) and mental aspects (MCS), as well as for all other factors determining quality of life. Both Petreli and Zhang also observed significant improvement in quality of life after bariatric treatment.^16,19 In our study, observed changes were similar in groups of patients with initial BMI <50 kg/m² and BMI >50 kg/m². The total quality-of-life index increased from 86 points to 147 points in the group of patients with BMI <50 kg/m² and from 85 points to 143 points in the group of patients with BMI >50 kg/m². No statistically significant difference was noted for improvement in the total quality of life between the two groups (p = 0.36). Furthermore, the observed improvement in quality of life in terms of physical (PCS) and mental health (MCS), as well as other components of the SF-36 questionnaire was similar in both groups. Moreover, no statistically significant differences were observed for improvement in quality of life depending on the type of surgery, both within each group and between the two groups. No studies are available for analyzing improvement in quality of life after bariatric treatment, depending on initial BMI, to which current results could be compared.

Summing results of the conducted study, it can be said that super obesity with its accompanying complications significantly deteriorates quality of life. What is interesting, this seems to be independent of an obesity stage or the presence of its most severe complications. Surgical treatment with the LSG or with the laparoscopic gastric bypass led to a reduction in body weight, an improvement in comorbidities, as well as a positive effect on quality of life of treated patients. The observed effect appears to be independent of the initial body weight or qualification for surgical treatment. Although the postsurgery body weight observed in the group of patients with a higher initial BMI still remains higher versus the body weight of patients with lower body weight, quality of life in both groups improved to a comparable extent, achieving a similar post-treatment level. The fact that quality of life after bariatric treatment improves so spectacularly seems to be one of the main arguments supporting use of surgery for treatment of patients with super obesity. Further studies on effects of surgical treatment of obesity on quality of life of operated patients seem to be necessary, to determine a group of patients most benefiting from the applied treatment.

Footnotes

Author Disclosure Statement

No competing financial interests exist.

Ethical Approval

The study has been approved by the Ethics Review Committee of the Jagiellonian University (approval number KBET/156/B/2011) and has been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.

Informed Consent

Informed consent was obtained from all individual participants included in the study. All participants gave their informed consent in writing at the day of admission to hospital.

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