Bariatric Surgery Doubled Fracture Risk

Researchers at the Mayo Clinic in Rochester, MN were recently puzzled by a pattern of increased risk of fractures among bariatric surgery patients. At the Endocrine Society meeting in June in Washington, DC, Jackie Clowes, MD, PhD reported that the risk of fractures, particularly of the hands and feet, was inexplicably 3 to 4 times greater than normal among 97 of 300 patients who underwent surgery for obesity between 1985 and 2004. The mean age of affected patients was 44 years, and 86 were women. Ninety percent of the procedures were gastric bypasses, and the rest were either banded gastroplasty or biliopancreatic diversion. Follow-up was continued for at least 7 years.

Compared to the rate of fracture expected in an age- and sex-matched cohort, the rate for a first fracture at any site was 2 times higher for patients who had bariatric surgery. First fractures at any site, including the spine, wrist or humerus, was 1.4 times greater; however, hand fractures were 3.2 times more common and of the foot, 3 times more common.

Most of the fractures occurred more than two years after bariatric surgery, suggesting they were a late complication, according to Dr. Clowes. She noted that although aggressive calcium and vitamin D supplementation after surgery may help, it may not be enough to prevent the risk. Did obesity have a protective effect against such fractures or were the fractures a complication of bariatric surgery? Ongoing follow-up may uncover clues to the answer.