Roux-en-Y gastric bypass is associated with a higher risk of non-vertebral fractures compared with adjustable gastric banding, a US study suggests.

Harvard University researchers identified more than 42,000 severely obese adults (79% women) who underwent bariatric surgery from Medicare claims data.

Current US guidelines recommend taking calcium citrate and vitamin D for life after bariatric surgery, and the aim of the study was to see whether bone health was affected differently in patients undergoing two different procedures, the authors said.

Among some 30,000 patients having gastric bypass, the risk of a non-vertebral fracture was 73% higher than in 13,000 treated with adjustable banding, over a mean of 3.5 years of follow-up, the authors wrote in JAMA Surgery.