Bariatric surgery patients at higher risk for broken bones

Patients who undergo bariatric surgery may be at a greater risk for fractures, according to researchers at the Mayo Clinic in Rochester, Minn.

The investigators, who presented their findings at the Endocrinology Society Annual Meeting in Washington, found that the bones in the hands and feet had the greatest fracture risk.

They studied 97 patients for more than 21 years; 90% of the patients underwent gastric bypass and the others received either vertical banded gastroplasty or biliopancreatic diversion. Twenty-one patients suffered one or more fractures for a total of 31 fractures.

“We knew there was a dramatic and extensive bone turnover and loss of bone density after bariatric surgery, but we didn't know what that meant in terms of fractures,” senior author and Mayo rheumatologist Jackie Clowes, MD, PhD, said in a Mayo press release.

Compared with the fracture rate expected in an age- and sex-matched population in southeastern Minnesota, the patients who underwent bariatric surgery were 1.8 times more likely to have a first fracture at any site in the body. Fractures were especially common in the hands and feet, with the risk of hand fracture being more than three times greater than average, and foot fracture risk nearly four times greater, according to the press release.

Researchers pointed to the possibility that the reduced availability of calcium, supplied through food or mineral supplementation, can contribute to a reduced bone density. A reduction in the surface area of the GI tract available for nutrient absorption plus a reduction in weight could explain the tendency for bones to fracture.

“We have shown that risk of fractures after this type of weight loss surgery is clinically significant,” Elizabeth Chittilapilly Haglind, MD, a Mayo endocrinologist and the study’s lead author, said in the press release. “More research is needed to confirm our findings and understand the specific risk factors and mechanisms involved.”