Impact of Bariatric Surgery on Cardiorespiratory Function

Study Overview
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Brief Summary
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Obesity is a growing problem worldwide and its prevention has become one of the leading priorities for the World Health Organisation. Obesity results from chronic imbalance between energy intake and energy expenditure. Although early prevention of obesity is preferable, surgical treatment is often required for severely obese people. Bariatric surgery has been shown to be the most effective therapy for severe obesity. Weight loss following bariatric surgery results in significant improvements in coexisting comorbidities, such as diabetes and hypertension but there is controversy whether bariatric surgery also improves aerobic capacity. The purpose of this study is to investigate the effects of bariatric surgery on cardiopulmonary function and on daily physical activity. It is hypothesized that bariatric surgery will improve aerobic capacity and result in beneficial lifestyle changes from sedentary to more active.

Official Title
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Impact of Bariatric Surgery on Cardiorespiratory Function: an Observational Study

Conditions
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Obesity, Bariatric Surgery Candidate, Physical Activity

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Ages 18 years to 50 years Patients enrolled in the bariatric surgery program of St George's Hospital with BMI > 40 kg/m2, or 35-40 kg/m2 in the presence of other obesity-related comorbidities such as hypertension or type- 2 diabetes Exclusion Criteria: Locomotor difficulties which would prevent participants from completing the cardiopulmonary exercise testing Weight > 190 kg (due to weight restrictions of equipment used to transfer patients in the event of medical emergencies) Cognitive impairment Patients unable to follow instructions in English

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiorespiratory function assessed by peak oxygen consumption (VO2peak) |  | One to two weeks before surgery and six months after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lung function | Lung function will be assessed by spirometry and body plethysmography | One to two weeks before surgery and six months after surgery | 
| Heart function | Echocardiography will be performed to assess heart function. | One to two weeks before surgery and six months after surgery | 
| Inspiratory muscle strength | Maximal inspiratory pressure and sniff nasal pressure will be recorded. | One to two weeks before surgery and six months after surgery | 
| Peripheral muscle strength | Maximum isometric strength of hand/ forearm, quadriceps and hip flexors muscles will be evaluated | One to two weeks before surgery and six months after surgery | 
| Free living sedentary and physical activity times | Daily physical activity habits will be assessed by an accelerometer and International Physical Activity Questionnaire: Long (IPAQ-Long). Participants will be required to wear the accelerometer for four consecutive days during the two study points. | One to two weeks before surgery and six months after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, Bariatric surgery, physical activity, cardiopulmonary exercise test