Introduction: Bariatric and metabolic surgery is effective for weight reduction but may induce substantial declines in skeletal muscle and bone mineral content, increasing the risk for sarcopenia and osteopenia. We aimed to study longitudinal changes in anthropometry, body composition, muscle strength, and bone mineral parameters after MBS, and to identify eventual predictors of postoperative sarcopenia and osteopenia, 18 months after surgery. Methods: Adults undergoing BMS were evaluated at baseline and 1, 6, 12, and 18 months. Dual-energy X-ray absorptiometry (DEXA) measured fat mass, lean mass, appendicular skeletal muscle mass (ASMM), bone mineral content (BMC), and bone mineral density (BMD). Handgrip strength and biochemical markers (PTH, vitamin D, leptin, ghrelin, NRI) were also evaluated. Regression models identified predictors of sarcopenia and osteopenia. Results: Body weight decreased from 112.4±17.5kg112.4±17.5kg to 72.5±10.9kg72.5±10.9kg at 18 months (p<0.001)(p<0.001). Significant reductions occurred in lean mass (56.5±10.1÷37.5±7.9kg;p<0.001)(56.5±10.1÷37.5±7.9kg;p<0.001)and ASMM (23.9±4.7÷15.4±4.3kg;p<0.001)(23.9±4.7÷15.4±4.3kg;p<0.001). Handgrip strength partially recovered after an early decline but did not return to baseline. BMC decreased steadily (2459±426÷2022±365g;p<0.001)(2459±426÷2022±365g;p<0.001) with declines in T-score (0.47→−0.30;p=0.012)(0.47→−0.30;p=0.012). Muscle-related indices (ASMM, ASMMI, ASMM/BMI) were the strongest predictors of both sarcopenia and osteopenia (r2(r2up to 0.562; p<0.001)p<0.001). Vitamin D, PTH, leptin, and ghrelin were not significant predictors. Conclusion: MBS may lead to substantial muscle and bone mineral losses, with ASMM-based indices emerging as key predictors of postoperative sarcopenia and osteopenia. Early interventions, targeting muscle preservation, are essential in postoperative management.
Carvalho et al. (Wed,) studied this question.