Exercise Training Reduces Bone Loss Tied to Gastric Bypass in Women

By Will Boggs MD

August 06, 2019

NEW YORK (Reuters Health) - Exercise training can attenuate the bone loss that commonly follows Roux-en-Y gastric bypass (RYGB) in women with severe obesity, according to results from a randomized controlled trial.

"Bariatric surgery is considered the gold-standard treatment in morbid obesity; however, this procedure is not free of adverse events, with bone loss being one of the most severe outcomes as this predisposes to fractures," Dr. Bruno Gualano of the University of Sao Paulo, in Brazil, told Reuters Health by email. "In this study, we showed that exercise is an effective, simple, potentially non-expensive, therapeutic tool to mitigate bone loss in obese patients undergoing bariatric surgery."

Increased bone turnover can occur as early as three months after bariatric surgery and can persist beyond 10 years. Limited data suggest that a multifaceted intervention that combines exercise with vitamin D, calcium and protein supplementation can partially mitigate this bone loss.

Dr. Gualano and colleagues investigated the effects of exercise training on bone mass, microarchitecture and bone metabolism in their study of 35 women assigned to RYGB without a formal exercise program and 35 women assigned to RYGB plus exercise training (six months with one-on-one supervised exercise training at the hospital three times a week, beginning three months after surgery).

After surgery, both groups experienced significant losses in femoral neck, total hip, distal radius, and whole-body areal bone-mineral density (BMD), as well as increased bone-turnover markers.

At month 9, the exercise group showed significantly smaller losses at the femoral neck (-4.41% vs. -7.33%), total hip (-5.00% vs. -7.26%), and distal radius (-2.75% vs. -4.62%), the researchers report in The Journal of Clinical Endocrinology and Metabolism, online July 19.

The losses in areal BMD at the whole-body level did not differ significantly between the exercise (-2.93%) and RYGB-alone (-4.14%) groups (P=0.078).

Among microarchitecture parameters, only the loss of cortical volumetric BMD at the distal radius was significantly attenuated in the exercise group.

Compared with RYGB-alone, RYGB plus exercise was associated with significantly smaller increases in collagen type I C-telopeptide, procollagen type I N-propeptide and sclerostin.

"Altogether, these findings suggest that efforts focused on improving lifestyle (e.g., adding exercise) should be put forward even (or perhaps especially) following bariatric surgery, in order to enhance and maintain the benefits of the surgery, as well as to mitigate its detrimental effects," Dr. Gualano said.

Dr. Anne L. Schafer of the University of California, San Francisco, and San Francisco VA Health Care System, who studies bone health following bariatric surgery, told Reuters Health by email, "Despite its beneficial effects on weight, obesity comorbidities, and mortality, gastric bypass surgery has negative effects on the skeleton. Research to date has focused mainly on characterizing the negative skeletal effects of gastric bypass surgery. Now, we need rigorous interventional trials to test strategies to prevent the negative skeletal effects. This study is therefore important because of its randomized controlled trial design."

"The negative skeletal effects of gastric bypass surgery are multifactorial," she explained. "The exercise intervention was able to mitigate increases in bone turnover and decreases in BMD but not prevent them entirely. Nevertheless, a 3-times-a-week, 60- to 90-minute intervention is feasible and has numerous benefits beyond skeletal health, so its application to the postoperative gastric bypass surgery population just makes sense."

Dr. Schafer added, "It is noteworthy that in post-hoc analyses, the exercise intervention mitigated increases in bone turnover and decreases in BMD independently of weight loss and change in lean mass. This suggests the skeletal health benefits may be at least in part due to direct effects of weight-bearing. The between-group difference in sclerostin levels could support this."

SOURCE: https://bit.ly/2T2qGRH

J Clin Endocrinol Metab 2019.