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NCT Number: NCT01352403

Severe Obesity: Bariatric Surgery vs. Life-Style-Intervention

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.

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Key information

Conditions

Obesity Body Weight Cardiac Function Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Overweight Pathological Conditions, Signs and Symptoms Quality of Life Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University hospital, University of Wuerzburg

Würzburg, Bavaria, 97080, Germany

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Roux-en-Y gastric bypass

Procedure

Psychotherapy-enhanced lifestyle intervention

Behavioral

Primary outcomes

  1. Change of peak VO2 to assess cardiorespiratory performance

    Time frame: 12 months after surgery / lifestyle intervention

    Change of peak V O2 (measured in ml/min/kg bw) in cardiopulmonary exercise testing (CPET)

  2. Change in physical functioning scale (PFS) of the SF-36 to assess quality of life

    Time frame: 12 months after surgery / lifestyle intervention

    Change of quality of life measured with physical functioning scale (PFS) of the SF-36 questionnaire (Short Form health survery 36). The score ranges from 0-100 and higher values correspond to better quality of life.

Secondary outcomes

  1. Change in health related quality of life (other domains than physical functioning scale)

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Change in quality of life (using Short Form (SF-36) health survey 36). The score ranges from 0-100 and higher values correspond to better quality of life.

  2. Change in left ventricular mass (index)

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment with echocardiography (g and g/m^2 body surface area)

  3. Changes in left atrial dimensions

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment with echocardiography (left atrial enddiastolic volume (mm^3), left atrial enddiastolic diameter (mm))

  4. Changes in left ventricular dimensions

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment with echocardiography (left ventricular enddiastolic volume (mm^3), left ventricular enddiastolic diameter (mm))

  5. Change in left ventricular systolic function

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment with echocardiography (left ventricular ejection fraction (%), longitudinal strain)

  6. Change in prevalence of left ventricular diastolic dysfunction

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment with echocardiography (Defined as reduced LVEF, LV hypertrophy, or LV dilation, as well as if three out of the following four criteria were fulfilled 77: LA dilation, average E/e' >14, lateral e' <0.1 m/s or septal e' <0.07 m/s, tricuspid regurgitation maximal flow velocity >2.8 m/s)

  7. Change in physical performance

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Distance (m) achieved in the 6 minute walk test

  8. Change in brain morphology

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Structural MRI of the brain to assess change in grey matter volume of the cerebellum (compared to normal weight controls)

  9. Change in brain activity

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Functional MRI of the brain to assess activation to high caloric food stimuli in obese patients in insula and anterior cingulate gyrus (compared to normal weight controls)

  10. Change in brain oxygenation

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Functional near-infrared spectroscopy (fNIRS) with assessment of frontal cortical oxygenation during Verbal Fluency Test and Trail Making Test and assessment of low frequency oscillations in resting state (in comparison to normal weight controls)

  11. Change in left ventricular function

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Cardiac MR imaging with analysis of left ventricular function (left ventricular ejection fraction, %)

  12. Change in cardiac lipid content

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Cardiac MR imaging with spectroscopy to measure cardiac lipid content (% fat content)

  13. Change in depressed mood

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment of depressed mood using Patient Health Questionnaire 9 (PHQ-9). The score ranges from 0-27, higher values correspond to more pronounced depressive symptoms.

  14. Change in depression

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment of depressed mood using Beck's Depression Inventory (BDI-II). The score ranges from 0-63, higher values correspond to more pronounced depressive symptoms.

  15. Change in liver stiffness

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment of liver stiffness using transient elastography (kPa)

  16. Change in liver triglyceride content

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment of liver triglyceride content with MR spectroscopy (% liver fat)

  17. Change in burden of comorbidities (type 2 diabetes mellitus)

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment of type 2 diabetes by predefined criteria. If the patient fulfils one of the following criteria, he/she would count as diabetic patient: fasting blood sugar level >= 126mg/dl, A1c => 6.5%, glucose of >=200 mg/dl 2hours in oral glucose tolerance test, or use of at least one antidiabetic medication.

  18. Change in burden of comorbidities (arterial hypertension)

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment of arterial hypertension according to predefined criteria. If the patient fulfils one of the following criteria, he/she would count as antihypertensive: systolic blood pressure >= 140mmHg, diastolic blood pressure >= 90mmHg, or use of at least one antihypertensive drug.

  19. Change in burden of comorbidities (dyslipidemia)

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment of dyslipidemia according to predefined criteria (depending on values for fasting triglycerides and ldl-cholesterol, lipid lowering medication)

  20. Change in NYHA functional class

    Time frame: 12 and 24 months after bariatric surgery / lifestyle intervention

    Assessment of NYHA functional class (NYHA I-IV, a higher class meaning more dyspnea)

Sponsors and collaborators

Lead sponsor

University of Wuerzburg

Other

Collaborators

  • German Federal Ministry of Education and Research

Registry information

Official study title

Severe Obesity: Bariatric Surgery vs. Life-Style-Intervention Wurzburg Adipositas Study - WAS

Acronym: WAS

Important dates

Study start
2011
Primary completion
2018
Study completion
2019
First posted
May 11, 2011
Registry last updated
Feb 8, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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