Energy expenditure of household activities and cardiorespiratory fitness in women with obesity

Impact of Bariatric Surgery on Women Aerobic Exercise Capacity

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.