Exercise training may mitigate bone loss observed after bariatric surgery and should be recommended for patients who have undergone Roux-en-Y gastric bypass (RYGB), according to study results published in The Journal of Endocrinology & Metabolism.
Bariatric surgery may reverse cardiometabolic risk factors and reduce mortality risk, but increased bone loss is an important detrimental effect of this procedure. While previous studies have reported that exercise training can mitigate bone loss in several populations, there are limited data regarding the specific effects of exercise on bone metabolism in patients who have undergone bariatric surgery.
The goal of this study was to assess the effects of exercise training on bone structure and metabolism after RYGB. The primary outcome was areal bone mineral density (aBMD) and secondary outcomes included the effects of exercise training on bone microarchitecture and bone turnover markers.
The randomized controlled trial included data from patients with severe obesity treated at the Bariatric and Metabolic Surgery Unit of the University Hospital in Sao Paulo, Brazil, between March 2015 and November 2018. The study cohort included women aged 18 to 60 years with a body mass index >40 kg/m2 or ≥35 kg/m2 with associated comorbidities who were not already taking part in an exercise training program.
Of 230 patients eligible for RYGB, 70 women met the inclusion criteria and were randomly assigned to undergo either RYGB (35 patients) or RYGB with exercise training (35 patients). After 7 withdrawals before surgery, the final analysis included 32 patients (mean age, 42.1±8.2 years) in the RYGB group and 31 patients (mean age, 40.0±7.8 years) in the RYGB and exercise training group.
The results showed that RYGB was associated with global changes in bone metabolism, with detrimental effects on femoral neck, total hip, distal radius, and whole body aBMD (P <.001).
There were no significant differences in the decrease in aBMD at the lumbar spine or whole body after surgery with or without exercise training. However, compared with standard care, the relative loss in aBMD was less severe in patients who underwent exercise training after RYGB at the femoral neck (-4.41%±3.30% vs -7.33%±3.70%; P =.007), total hip (-5.00%±2.80% vs -7.26%±2.90%; P =.009), and distal radius aBMD (-2.75%±2.60% vs -4.62%±3.36%; P =.038).
Exercise was also accompanied by a decrease in bone turnover markers, with a reduction in C-terminal telopeptide of type 1 collagen (CTX) (P =.002) and procollagen type 1 N-terminal propeptide (P1NP) (P =.024). Sclerostin significantly increased in both groups of patients 3 months after RYGB, but after 9 months was significantly reduced in patients participating in exercise training compared with standard care (P =.046).
The study had several limitations, including its short duration, small sample size, and lack of data regarding eating habits.
“These findings support the clinical view that exercise should be incorporated into post-op care of bariatric patients in order to retain cardiometabolic benefits, and suggest that exercise therapy may also mitigate the adverse effects of the surgery on bone mass,” concluded the investigators.
Murai IH, Roschel H, Dantas WS, et al. Exercise mitigates bone loss in women with severe obesity after Roux-en-Y gastric bypass: a randomized controlled trial [published online July 19, 2019]. J Clin Endocrinol Metab. doi:10.1210/jc.2019-00074