RESUMO
RATIONALE: Bariatric surgery has a considerable positive effect on weight loss and on metabolic and cardiovascular risks. It has therefore been extensively used this last decade to overcome obesity. However, the impact of this surgery on exercise capacity remains unclear. The aim of this study is to clarify the impact of a surgically induced weight loss on aerobic exercise capacity (VO2max) in a specific middle-aged female population. METHODS: Forty-two women with a body mass index > 40 kg/m2 (age, 42 ± 13 years; weight, 117 ± 15 kg) underwent blood analyses and a cardiopulmonary exercise test (CPET) before and 1 year after bariatric surgery. CPET was performed on a cycloergometer. The first ventilatory threshold (VT1) was measured according to the V-slope method. RESULTS: Absolute VO2max was reduced by 10% after surgery (2.0 ± 0.4 vs 1.8 ± 0.4 l/min, p < 0.01) or increased when corrected for body weight (18 ± 4 vs 23 ± 4 l/min/kg, p < 0.001) or unchanged when expressed as percentage of predicted values (111 ± 21 vs 105 ± 22, p = 0.06). Weight loss did not affect ventilatory or chronotropic response but increased maximal respiratory exchange ratio (RER) (p < 0.001), decreased maximal O2pulse (p < 0.05) and VT1 in milliliters per minute (p < 0.01). By multivariable analysis, decreased absolute VO2max after weight loss was associated with increased maximal RER and reduced maximal O2pulse (p < 0.05, p < 0.01 respectively), possibly related to a muscular mass limitation. CONCLUSIONS: Weight loss induced by bariatric surgery may reduce aerobic capacity in women in relation to muscle mass loss.
