Clinical trial NCT01352403: Severe Obesity: Bariatric Surgery vs. Life-Style-Intervention
Official title: Severe Obesity: Bariatric Surgery vs. Life-Style-Intervention Wurzburg Adipositas Study - WAS
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obesity
Cardiac Function
Quality of Life
Keywords: obesity
bariatric surgery
gastric bypass
life style intervention
cardiac function
Lead sponsor: University of Wuerzburg
Sponsor class: OTHER
Collaborators: name: German Federal Ministry of Education and Research
First posted: 2011-05-11
Enrollment: 93
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to investigate the effects of weight loss induced by gastric bypass surgery in comparison to a psychotherapy-enhanced lifestyle intervention on cardiopulmonary performance and quality of life in patients with morbid obesity.

Detailed description: Obesity is a rapidly emerging health problem and an established risk factor for cardiovascular diseases. Bariatric surgery profoundly reduces body weight and mitigates sequelae of obesity. Especially randomized trials comparing the effects of bariatric surgery to conservative treatment in concerns of cardiac function are still lacking.

The randomized WAS trial compares the effects of Roux-en-Y gastric bypass (RYGB) versus psychotherapy-supported lifestyle modification in morbidly obese patients. The co-primary endpoint addresses 1-year changes in cardiovascular function (peak VO2 during cardiopulmonary exercise testing) and quality of life (Short-Form-36 physical functioning scale). Prior to randomization, all included patients underwent a multimodal anti-obesity treatment for 6-12 months. Thereafter, patients were randomized and followed through month 12 to collect primary endpoints. Afterwards, patients in the lifestyle group could opt for surgery, and final visit was scheduled for all patients 24 months after randomization.

The study was initially designed in 2008 as part of several interdisciplinary studies for a targeted grant and received a positive vote from the responsible ethics committee.

Prior the actual start of the study in July 2011, the initial study protocol and the patient informed consent were updated and further specified. This amendment was submitted to the Ethics Committee on June 9, 2011, with a positive vote on June 30, 2011 (Amendment 1).

An Amendment 2 was submitted to Ethics Committee on 08.10.2014 (positive vote 16.12.2014) to adjust randomization (previously 1:1 to the two study arms) for an unequal drop-out rate in the two study arms with higher rate in the intensified lifestyle modification. In addition, few secondary endpoints were adapted and the role of the principal investigator changed from Prof. Stefan Frantz to Prof. Martin Fassnacht.

Eligibility criteria: Inclusion Criteria:

* Age ≥18 years
* BMI \>40 kg/m2 or BMI \>35 kg/m2 with severe comorbidities
* Indication for Roux-en-Y gastric bypass surgery
* Ability to perform cardiopulmonary exercise testing (CPET)
* Written informed consent

Exclusion Criteria:

* Pregnancy or breast feeding
* Unstable angina pectoris
* Life expectancy \<12 months
* Endocrine or psychiatric disorder as cause of obesity
* Systemic glucocorticoid treatment (with exception of glucocorticoid replacement therapy)
* Abuse of drugs or alcohol within the last 5 years
* Inability to attend regular study visits for logistic reasons
* Participation in competing trials

Primary outcomes:
measure: Change of peak VO2 to assess cardiorespiratory performance
timeFrame: 12 months after surgery / lifestyle intervention
measure: Change in physical functioning scale (PFS) of the SF-36 to assess quality of life
timeFrame: 12 months after surgery / lifestyle intervention
Secondary outcomes:
measure: Change in health related quality of life (other domains than physical functioning scale)
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in left ventricular mass (index)
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Changes in left atrial dimensions
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Changes in left ventricular dimensions
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in left ventricular systolic function
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in prevalence of left ventricular diastolic dysfunction
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in physical performance
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in brain morphology
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in brain activity
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in brain oxygenation
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in left ventricular function
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in cardiac lipid content
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in depressed mood
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in depression
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in liver stiffness
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in liver triglyceride content
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in burden of comorbidities (type 2 diabetes mellitus)
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in burden of comorbidities (arterial hypertension)
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in burden of comorbidities (dyslipidemia)
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
measure: Change in NYHA functional class
timeFrame: 12 and 24 months after bariatric surgery / lifestyle intervention
Other outcomes:
Locations:
city: Wuerzburg
country: Germany
facility: University hospital, University of Wuerzburg
state: Bavaria
Study officials:
References:
citation: Koschker AC, Warrings B, Morbach C, Seyfried F, Rickert N, Jung P, Geier A, Dischinger U, Krauthausen M, Herrmann MJ, Stier C, Frantz S, Malzahn U, Stork S, Fassnacht M. Cardio-psycho-metabolic outcomes of bariatric surgery: design and baseline of the WAS trial. Endocr Connect. 2022 Feb 9;11(2):e210338. doi: 10.1530/EC-21-0338.