Consequences of bariatric surgery on bone metabolism and fracture risk - What is the therapeutic role of exercise? The bariatric Surgery and Exercise Intervention Bone Trial - BaSEIB Clinical Trial

Abstract

Bariatric surgery (BS) is the most effective treatment for severe obesity, but it is also associated with some adverse effects such as increased fracture risk. This could be attributed to accelerated bone loss and increased risk of fall after BS. The etiological mechanisms underlying bone loss and increased fall risk after BS are, however, largely unknown. There is currently no pharmacological treatment approved for preventing BS-induced bone loss. Considering its usefulness in other pathological contexts, physical exercise could be a potential therapeutic strategy for mitigating post-BS bone loss and fall risk. However, there is little evidence substantiating its effectiveness in post-BS patients. To address this gap in the literature we conducted five studies, namely to i) investigate the effect of BS on bone mass and its determinants; ii) describe changes in fall risk factorsafter BS; iii) assess whether an exercise training program can mitigate bone mass losses after BS; iv) systematically review and meta-analyze the evidence regarding the effect of exercise in the prevention of bone mass loss after BS; and v) to verify if an exercise training program can improve fall risk factors such as balance in post-BS patients. Overall, our results showed that: i) despite the association between weight loss and bone mass loss throughout the first year after BS, bone loss does not seem to result from a decrease in skeletal gravitational loading; ii) 6-months after BS, patients tend to overestimate their actual physical fitness improvements, which, combined with increases in physical activity, might increase the likelihood of engaging in activities for which they are physically ill prepared to, increasing thereby fall risk; iii) an 11-month multicomponent exercise intervention was able to attenuate bone mass loss in post-BS patients; iv) the current evidence indicates that exercise after BS induces a positive effect on bone mineral density at several clinically relevant skeletal sites, but the strength of the evidence is low; and v) a 5-month multicomponent exercise intervention was able to improve several balance parameters in post-BS patients. Together, our results suggest that exercise is an effective therapeutic option to reduce bone mass loss and fall risk increase after BS and thereby to minimize the risk of fracture in post BS patients.