Quality of Life in Patients with Obesity: The Role of Multidisciplinary Rehabilitation Medicine

: Background: Little is known about the role of rehabilitation medicine in obesity. Objective: to examine the benefits of a multidisciplinary rehabilitation program on the quality of life in patients with severe obesity. Methodology: We included 124 patients with obesity (mean age: 57 years; BMI ≥ 30), in an 8-week in-hospital multidisciplinary supervised program combining physiotherapy, nutrition and psychological support. Clinical, bio-psychological and functional parameters, as well as an obesity-specific quality-of-life score, were acquired at 0 and 8 weeks. Results: The quality-of-life score improved significantly at 8 weeks, from 60.8 to 68.8 ( p < 0.0001), and was positively correlated with cardio-respiratory function (r = 0.47; p < 0.0001). Conclusions: Our results highlight the important role of multidisciplinary rehabilitation medicine and its integrated approach to improve the quality of life of people with obesity.


Introduction
According to the World Health Organization, the worldwide prevalence of obesity (defined as a BMI ≥ 30 kg/m 2 ) has nearly tripled since 1975, affecting 650 million adults [1].The prevalence of obesity is generally higher in women than in men in all age groups.In France, recent surveys have found obesity to have an estimated prevalence of 15% [2].
Obesity can affect all physiological body functions.People with obesity exhibit significant adverse health outcomes, including cardio-metabolic and respiratory disorders, type 2 diabetes and musculoskeletal problems [3][4][5].Additionally, a decline in muscle mass and strength, known as sarcopenia, is very common among patients with obesity [6].These conditions can rapidly lead to a loss of functional independence, psychosocial issues, diminished quality of life and reduced lifespan [7,8].
Current obesity management include dietetics, bariatric surgery and, more recently, incretin-based therapy [9][10][11].In addition, rehabilitation centers have been developed in recent years.They offer multidisciplinary intensive lifestyle intervention programs based on a combination of physical therapy, nutrition and psychological support [12,13] and are associated with a 5-8% weight loss and an improvement in cardiovascular risk [14][15][16].However, little is known about their impact on the quality of life.The aim of this study was to assess the specific effects of a dedicated rehabilitation program on the quality of life in patients with obesity.care of patients with severe obesity, at the Maritime Hospital (Greater Paris University Hospitals, AP-HP, Berck, France).The protocol conformed to the principles outlined by the Declaration of Helsinki and was in accordance with the French CNIL requirements (National Committee for the Protection of Privacy and Personal Data).All participants provided written informed consent.
Patients were eligible if they were between 18 and 65 years, had a BMI ≥ 30 kg/m 2 , and had at least one comorbidity (hypertension, type 2 diabetes, sleep apnea, cardiovascular disease, osteoarthritis) and had been on stable medication for at least 3 months prior to enrollment.The patients were referred by endocrinology departments and family doctors.They were then hospitalized in our unit for a mean duration of 8 weeks.
The exclusion criteria were severe cardiac or pulmonary disease, musculoskeletal disorders that precluded exercise training, and significant cognitive disorders.Candidates were also excluded if they were unable to participate in the proposed therapeutic program.Each participant acted as his or her own control.
Patients received a standardized clinical examination and were then assessed by each interdisciplinary team member.All data were collected on admission to the program.

Exercise Intervention
The training program involved aerobic exercise (5 days per week).Each patient performed 2 h of exercise per day.Patients had 1 h session of land-based exercise in the morning, in the training room, and one 1 h session of aquatic-exercise (indoor swimming pool) in the afternoon.All sessions included 5 min of warm-up, 30-40 min of main work, 5 min of cooldown and 10 min of stretching.Groups of 4-8 participants performed exercise with a focus on improving muscle strength, endurance ability (walking, cycling, swimming), balance and flexibility (Pilates-inspired exercises), with adjustments according to individual perception of effort or pain.During each session, exercise, intensity and volume were individualized.All sessions were supervised by physiotherapists and certified trainers.

Nutrition Program
All participants had an initial nutritional assessment (24 h dietary recall and diet history), during a one-on-one consultation with a dietician.The estimated individual daily total energy requirements were calculated using the Harris-Benedict equation [17].Each patient received an individualized diet plan.The balanced diet approximately comprised 55% carbohydrates, 30% fats, and 15% protein (1 g of protein/kg of the ideal body weight).All meals were provided in our ward during the 8-week program.Additionally, weekly group-based educational meetings were organized to empower individual skills in nutrition and improve eating habits.

Psychological Support
A clinical psychologist assessed key clinical characteristics using interviews (1 h session) to collect data about each participant's life history, and the participants completed a series of self-ratings.Individual and group-based psychological interventions were delivered weekly (1 h session), targeting an improvement in general well-being, perception of physical ability, eating behavior, self-esteem and body image.

Outcome Measures 2.3.1. Anthropometric and Cardiometabolic Measurements
Clinical and biological measures, as well as body composition parameters, were measured at baseline and at the end of the 8-week program.
Height, weight and waist circumference (WC) were measured by the same investigator following standard procedures.Body mass index (BMI) was calculated as weight (kg)/height (m 2 ).Blood pressure and heart rate were measured using a sphygmomanometer with cuffs of appropriate size, according to standard procedures.
Plasma glucose, glycated hemoglobin A1c (HbA1c), lipoprotein levels, creatinine and albuminemia were measured in fasting blood samples using standard methods.
All of the assessments described below were conducted at baseline and repeated at the completion of the program.

Physical Fitness Assessment
Physical performance and cardiorespiratory fitness were assessed by the same physiotherapist by applying the 6 min walk test (6MWT), according to international guidelines and validated in obesity [18].The 6MWT was performed along a 100 m corridor in the ward.Pulse and oxygen saturation are measured before the start and at the end of the test.The patient may walk as fast as possible and is allowed to stop or rest during the test if needed.

Pain Assessment
We used the Numeric Rating Scale (NRS-11) to evaluate the severity of musculoskeletal pain.The patient is asked to rate the pain on a scale from 0 to 10, where 0 represents "no pain at all" and 10 represents "the worst pain a person has ever experienced".

Psychiatric Assessment
Given that anxiety disorders and depression are frequently linked to obesity, the Hospital Anxiety and Depression Scale (HADS) was administered to all study patients.This self-questionnaire is a simple, widely used tool for the detection of anxiety and depression in individuals with relevant physical health problems.The 14 items of the HADS are scored on a Likert scale from 0 (low symptom frequency) to 3 (high symptom frequency).The final score of each subscale (anxiety and depression) ranges from 0 (best) to 21 (worst).

Health-Related Quality of Life (QoL) Assessment
Health-related quality of life was assessed with the validated French version of the Quality Of Life Obesity and Dietetics scale (QOLOD) [19].The QOLOD is a 36-item scale that includes 5 dimensions-physical impact, psychosocial impact, impact on sex life, food rebalancing, and nutritional well-being.Each item is rated on a 5-point scale, and the results are expressed as percentages, with higher scores indicating a better QoL.

Statistical Analysis
For descriptive analysis, categorical variables are presented as frequencies/percentages and compared using the Pearson χ 2 test or Fisher's exact test, as appropriate.Continuous variables are presented as the mean ± standard deviation or median [range].The efficacy of the rehabilitation program was tested with Student's t test for quantitative variables collected at the beginning and at the end of the program.The associations between the QoL score and changes in variables of interest were assessed using Spearman's correlation coefficient.
We used a simple linear model to assess the associations between changes in variables of interest and the change in QoL.Variables associated with QoL at 10% α-risk in the univariate analyses were used to build a multiple linear model with backward selection.Before modeling, we used a multiple imputation technique with 10 replications to impute missing data, resulting in 10 backward selected linear models.Finally, a multiple full linear model was fitted using all the variables that were selected more than five times among the ten replicated backward models.A two-sided p value < 5% indicated statistical significance.
The analyses were performed with R software, version 4.0.5 (R Foundation for Statistical Computing, Vienna, Austria; www.r-projet.org,accessed on 22 December 2020).

Demographics and Medical Conditions of the Participants
The 124 patients had a mean (SD) age of 57 ± 12 years, and 65% were women.The mean BMI at baseline was 46.2 ± 10 (kg/m 2 ).The prevalence of obesity-related comorbidities is detailed in Table 1.After rehabilitation, the group showed significant weight loss (mean: −9 kg), an improved BMI from 46.2 to 42.8 and a decreased waist circumference and fat mass (p < 0.05) (see Table 2).

Functional Parameters
The mean walk distance measured by the 6 min walk test increased from 324 m to 441 m, corresponding to a gain of +43% (p < 0.0001).The mean intensity of musculoskeletal pain significantly decreased from 6 to 3.6 (p < 0.0001).

Quality of Life and Psychiatric Symptoms
The global score of QoL significantly rose (see Table 3).Improvement in QoL was positively correlated with the increase in the 6 min walk test (r = 0.47; (p < 0.0001)).Both the anxiety and depression symptoms scores significantly decreased (p < 0.001).In the multivariate analysis, the reduction in the anxiety and depression scores were associated with QoL (see Table 4).

Discussion
As expected, in our population of patients, a personalized normal-calorie diet combined with a training program resulted in significant weight loss, mainly due to a reduction in fat mass and an improvement in fat distribution (i.e., a reduction in visceral adiposity as indicated by a reduction in waist circumference).However, the lean mass (which reflects muscle mass) remained stable in our patients.Our results corroborate those of Colleluori et al., affirming that, unlike weight loss induced by a restrictive hypocaloric diet alone (resulting in a reduction in fat mass and also muscle mass), a program combining nutrition and physical activity may prevent sarcopenia and may improve the QoL of obese patients [6].Additionally, Fontana et al. demonstrated that a 4-week multidisciplinary rehabilitation protocol for patients with obesity and a post-COVID-19 condition was effective on physical performance, reduction in pain and improvement in psychological well-being [20].
In our study, the increase in 6MWT was positively correlated with the improvement in the QoL of our patients, thus highlighting the major role of functional rehabilitation in terms of quality of life [21].
Regarding psychological status, a reduction in the anxiety and depression scores after the therapeutic program was significantly associated with an improvement in QoL.It is well established that physical exercise positively affects mental health [22].There are also consistent positive effects of dietary interventions on anxiety and depression symptoms [23].Given the potentially cumulative effects of diet, exercise and psychological care, we believe that the physical and psychological amelioration observed in our patients contributed to improved functional capacities and, consequently, an improved QoL.
Despite the increased understanding of the complex pathophysiology of obesity (e.g., regarding genetics, inflammation, neuro-endocrine disorders, psychiatric conditions and a myriad of environmental factors), traditional approaches in obesity management have mainly focused on weight loss achievement (i.e., obtaining a negative energy balance through dietary changes and exercise or bariatric surgery).By contrast, in our study, we focused on outcomes that are often considered secondary, such as quality of life (QoL).Indeed, as a chronic disease, obesity is characterized by slow progression and long duration, which affects several dimensions of overall health, such as one's physical and psychological capabilities, cardio-metabolic status, mobility and psycho-social well-being, thus creating a large variety of bio-psycho-social phenotypes of obesity [24].Interestingly, in a large longitudinal study including 4265 patients suffering from osteoarthritis (70% with overweight) who received a multidisciplinary program combining patient education and physiotherapy exercises (lasting 6-12 weeks), it was shown that in addition to significant weight loss over the 2-year follow-up period, 80% of the participants improved their quality of life and their activity limitations [25].
Therefore, taking into account the real-life difficulties experienced by patients with obesity (e.g., chronic pain, cardiorespiratory, mobility and affective disorders), QoL has become a primary therapeutic target and is an exciting opportunity through which to exert beneficial effects [26].Thus, multidisciplinary obesity centers that provide an integrated approach are needed.

Strengths and Limitations
This study presents two main strengths.First, it involved a rare, onsite, supervised program that accurately investigated the relationships between QoL and psycho-physical performance levels in patients with obesity.Second, our intervention program applied a multidisciplinary therapy for obesity treatment, including nutrition, exercise, psychological support and therapeutic patient education, which is in line with the recent clinical guidelines for the treatment of obesity that recommend a comprehensive and patient-centered approach [27].
Several limitations must be mentioned.First, our 124 participants may constitute a relatively small sample, and the short follow-up period of 8 weeks may appear insufficient for reaching definitive conclusions.A longer follow-up period, including outpatient assessment with visits at 6-and 12-month points, would be helpful to evaluate the longterm effectiveness and sustainability of this rehabilitation program.Additionally, in this study, the patients sought help for obesity at a specialized center, and therefore may not be representative of all patients with obesity.In the future, a control group with patients receiving ambulatory obesity care may be useful to precisely study the role of a hospitalbased program.Second, we must recall that our intervention is an intensive hospital program, which requires outpatient monitoring to remain effective, in order to maintain the benefits over the long term.Indeed, a mixed inpatient and outpatient obesity management program, with professionals trained in Therapeutic Patient Education, demonstrated its effectiveness on favorable weight change in 70% of participants after 5 years [28].Third, despite our methodology efforts to precisely characterize the participants, confounding factors such as medication changes and psychological support outside the program might have influenced the outcomes.Finally, this work did not include a cost-effectiveness analysis.However, when the healthcare system or patient preferences exclude bariatric surgery as an option, intensive behavioral multidisciplinary weight management programs appear to be valuable cost-effective interventions [29,30].

Conclusions
The associations between obesity, mobility disability, cardiometabolic disorders and psychological distress suggest the need for a global and integrative approach to health care.Our study highlights the role of a multidisciplinary rehabilitation program in patients with obesity to improve their QoL and abilities to perform activities of daily living.

Table 1 .
Demographics and medical conditions of the participants.

Table 2 .
Baseline and post-intervention measures.

Table 3 .
Measures of quality-of-life scale.

Table 4 .
Associations between quality of life and other parameters.