Cardio-psycho-metabolic outcomes of bariatric surgery: design and baseline of the WAS trial

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. The open, randomized controlled 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. Sample size calculation suggested to enroll 90 patients in order to arrive at minimally 22 patients per group evaluable for the primary endpoint. Secondary objectives were to quantify changes in body weight, left ventricular hypertrophy, systolic and diastolic function (by echocardiography and cardiac magnet resonance imaging [MRI]), functional brain MRI, psychometric scales, endothelial and metabolic function. WAS enrolled 93 patients (72 women, median age 38 years, BMI 47.5 kg/m2) exhibiting a relevantly compromised exercise capacity (median peakVO2 18.3 ml/min/kg) and quality of life (median physical functioning scale 50). WAS is the first randomized controlled trial focusing on the effects of RYGB on cardiovascular function beyond hypertension. In addition, it will provide a wealth of high-quality data on cerebral, psychiatric, hepatic, and metabolic function in obese patients after RYGB. The trial is registered at ClinicalTrials.gov (NCT01352403).

Physical activity measures in patients with myalgic encephalomyelitis/chronic fatigue syndrome: correlations between peak oxygen consumption, the physical functioning scale of the SF-36 questionnaire, and the number of steps from an activity meter

Background most studies to assess effort intolerance in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) have used questionnaires. Few studies have compared questionnaires with objective measures like an actometer or an exercise test. Therefore three measures of physical activity in ME/CFS patients, being the physical functioning scale (PFS) of the SF-36, the number of steps/day (Steps) of an actometer and the %peak VO 2 of a cardiopulmonary stress test were compared. Methods female ME/CFS patients were selected from a clinical database if the three types of measurements were available, and the interval between measurements was ≤ three months. Data of the three measures were compared by linear regression. Results in 99 female patients the three different measures were linearly, significantly and positively correlated (PFS vs Steps, PFS vs %peak VO 2 and Steps vs %peak VO 2 : all P<0.001). Subgroup analysis showed that the relations between the three measures were not different in patients with versus without fibromyalgia and with versus without a maximal exercise effort (RER≥1.1). In 20 patients re-evaluated for symptom worsening, the mean of all three measures was significantly lower (P<0.0001), strengthening the observation of the relations between them. Despite the close correlation a large variation was observed between the three measures in individual patients. Conclusions given the large variation in ME/CFS patients, the use of only one type of measurement is inadequate. Integrating the three modalities may be useful for patient care by detecting overt discrepancies and may aid study designs aimed at improving exercise capacity.

Physical activity measures in patients with myalgic encephalomyelitis/chronic fatigue syndrome: correlations between peak oxygen consumption, the physical functioning scale of the SF-36 questionnaire, and the number of steps from an activity meter

Background most studies to assess effort intolerance in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) have used questionnaires. Few studies have compared questionnaires with objective measures like an actometer or an exercise test. Therefore three measures of physical activity in ME/CFS patients, being the physical functioning scale (PFS) of the SF-36, the number of steps/day (Steps) of an actometer and the %peak VO 2 of a cardiopulmonary stress test were compared. Methods female ME/CFS patients were selected from a clinical database if the three types of measurements were available, and the interval between measurements was ≤ three months. Data of the three measures were compared by linear regression. Results in 99 female patients the three different measures were linearly, significantly and positively correlated (PFS vs Steps, PFS vs %peak VO 2 and Steps vs %peak VO 2 : all P<0.001). Subgroup analysis showed that the relations between the three measures were not different in patients with versus without fibromyalgia and with versus without a maximal exercise effort (RER≥1.1). In 20 patients re-evaluated for symptom worsening, the mean of all three measures was significantly lower (P<0.0001), strengthening the observation of the relations between them. Despite the close correlation a large variation was observed between the three measures in individual patients. Conclusions given the large variation in ME/CFS patients, the use of only one type of measurement is inadequate. Integrating the three modalities may be useful for patient care by detecting overt discrepancies and may aid study designs aimed at improving exercise capacity.