Exercise mitigates bone loss in women with severe obesity after Roux-en-Y gastric bypass: a randomized controlled trial.

CONTEXT: Bone loss after bariatric surgery potentially could be mitigated by exercise. OBJECTIVE: To investigate the role of exercise training (ET) in attenuating bariatric surgery-induced bone loss. DESIGN: Randomized, controlled trial. SETTING: Referral center for bariatric surgery. PATIENTS: Seventy women with severe obesity, aged 25 to 55 years, who underwent Roux-en-Y gastric bypass (RYGB). INTERVENTION: Supervised, 6-month, ET program after RYGB vs. standard of care (RYGB only). OUTCOMES: Areal bone mineral density (aBMD) was the primary outcome. Bone microarchitecture, bone turnover, and biochemical markers were secondary outcomes. RESULTS: Surgery significantly decreased femoral neck, total hip, distal radius, and whole body aBMD (P < 0.001); and increased bone turnover markers, including collagen type I C-telopeptide (CTX), procollagen type I N-propeptide (P1NP), sclerostin, and osteopontin (P < 0.05). Compared with RYGB only, exercise mitigated the percent loss of aBMD at femoral neck [estimated mean difference (EMD), -2.91%; P = 0.007;], total hip (EMD, -2.26%; P = 0.009), distal radius (EMD, -1.87%; P = 0.038), and cortical volumetric bone mineral density at distal radius (EMD, -2.09%; P = 0.024). Exercise also attenuated CTX (EMD, -0.20 ng/mL; P = 0.002), P1NP (EMD, -17.59 ng/mL; P = 0.024), and sclerostin levels (EMD, -610 pg/mL; P = 0.046) in comparison with RYGB. Exercise did not affect biochemical markers (e.g., 25(OH)D, calcium, intact PTH, phosphorus, and magnesium). CONCLUSION: Exercise mitigated bariatric surgery-induced bone loss, possibly through mechanisms involving suppression in bone turnover and sclerostin. Exercise should be incorporated in postsurgery care to preserve bone mass.