Assessment of Cardiorespiratory and Metabolic Responses in Women with Obesity After Surgically Induced Weight Loss: Results from a Pilot Study.

Abstract

Bariatric surgery is effective in controlling severe obesity. However, studies investigating the impact of surgically induced weight loss on cardiorespiratory and metabolic responses during maximal effort are controversial. The aim of this study was to assess cardiorespiratory and metabolic responses in women with obesity after bariatric surgery. We performed a secondary analysis on data from a pilot study with women with obesity submitted to bariatric surgery and who did not participate in a controlled physical training program. Anthropometry, pulmonary function (spirometry), and cardiorespiratory fitness (cardiopulmonary exercise testing [CPX]) were assessed before and after bariatric surgery. Thirty-four women were included (38.7 ± 9.6years, body mass index = 44.1 ± 6.3kg/m2). Postoperative assessment was conducted 9.4 ± 2.7months after surgery. After surgery, we observed a reduction in all anthropometric measurements (mean loss of 28.6kg, p < 0.001), and improvement in spirometry values (p < 0.001). Relative VO2peak (mL/kg/min) increased slightly (Δ = 1.7; p = 0.06); however, absolute VO2peak (L/min) reduced significantly (Δ = - 0.398; p < 0.001). We also observed an increase of 1.3min (p < 0.001) in CPX duration, a reduction of 11.3bpm (p < 0.001) in resting heart rate, and a decrease of systolic (p = 0.02) and diastolic (p < 0.001) blood pressures at peak effort. Surgically induced weight loss without exercise training improved cardiac reserve, ventilatory response, blood pressure, and resting heart rate. Cardiorespiratory fitness reflected by relative VO2peak increased slightly, despite increased tolerance to CPX.