Body composition changes in the first month after sleeve gastrectomy based on gender and anatomic site.

BACKGROUND:Sleeve gastrectomy (SG) induces acute weight loss, but its impact on the very early postoperative changes in body composition (BC) is less clear. OBJECTIVES:This longitudinal study examined the BC changes in the first month after SG according to gender and anatomic site. METHODS:BC (lean tissue mass [LTM] and fat mass [FM]) were determined by dual-energy x-ray absorptiometry in 41 obese patients (33 women, 80.5%) just before SG and 1 month later. SETTING:University hospital of Montpellier, France. RESULTS:One month after SG, mean weight loss was -9.8±2.6 kg, with a significant decrease in LTM and FM (kg) ranging from -7.3% to 9.5%, depending on site. FM (kg) loss in men exceeded that in women at whole body, upper limbs, and trunk. FM (%) and the LTM/FM ratio decreased only in the trunk in men and the lower limbs in women, but the gender difference was only observed for the trunk. In women, age was positively correlated with relative FM variation (% and kg) in the lower limbs and negatively correlated with LTM and LTM/FM. In men, weight was negatively correlated with the relative LTM and FM (kg) variations in the upper limbs. CONCLUSION:SG induces acute weight loss, but this loss comprises losses in both FM and LTM. Because excessive LTM loss can have deleterious consequences, preventive strategies should be implemented soon after bariatric surgery. The specific changes in BC are highlighted according to gender and anatomic site.