Higher risk of nonvertebral fracture following Roux-en-Y bypass vs gastric banding
Individuals with severe obesity who undergo Roux-en-Y gastric bypass (RYGB) may have a higher risk of nonvertebral fractures than those who undergo adjustable gastric banding (AGB), according to a study presented at the recent ENDO 2018 sessions.
“In a large US population-based cohort, RYGB was associated with a 65 percent increased risk of nonvertebral fractures relative to AGB,” said study lead author Assistant Professor Elaine W. Yu from the Massachusetts General Hospital in Boston, Massachusetts, US.
Researchers analysed data of 50,649 Medicare patients with severe obesity (78 percent female) who underwent either RYGB (n=35,920) or AGB (n=14,729) between 2006 and 2014. Patients who underwent RYGB were younger than those who underwent AGB (mean, 53 vs 56 years), were followed up for a shorter period of time (average, 3.1 vs 3.8 years), and also had a higher incidence of diabetes (36 percent vs 32 percent). There were 1,109 nonvertebral fractures documented over the follow-up period, with an estimated incidence rate of 9.8 and 7.1 per 1,000 person-years in patients undergoing RYGB and AGB, respectively.
After adjusting for a multitude of factors including age, sex, race, comorbidities, and medication use, patients who underwent RYGB had a 65 percent increased risk of developing any nonvertebral fractures compared with patients who underwent AGB (hazard ratio [HR], 1,65, 95 percent confidence interval [CI], 1.46–1.85). [ENDO 2018, abstract OR03-2]
Compared with patients who underwent AGB, those who underwent RYGB had a higher risk of pelvic (HR, 2.72, 95 percent CI, 1.24–6.86), hip (HR, 2.26, 95 percent CI, 1.79–2.88), and wrist fractures (HR, 1.62, 95 percent CI, 1.36–1.95).
The risk of nonvertebral fracture following RYGB was more apparent in men than women (HR, 2.08 vs HR, 1.42; p=0.02 for interaction). There was no evidence to suggest that age or diabetes status affected the risk of nonvertebral fracture in patients who underwent RYGB.
“Bariatric surgery procedures, such as RYGB, are highly effective treatments that induce sustained weight loss,” said Yu. “RYGB [also] leads to greater improvements in metabolic health than AGB.”
“We found that Medicare patients who received RYGB had more fractures compared with those who received AGB. Importantly, we found that RYGB increased the risk for hip, wrist, and pelvis fractures. RYGB increased fracture risk across all age groups, in men and in women, although the effects were more pronounced among men.”
“This research is very relevant given the high prevalence of obesity and increasing utilization of bariatric surgery. Over one-third of adults in the US are obese, and bariatric surgery procedures have accordingly been increasing in popularity,” said Yu, recommending that physicians discuss the long-term impact on bone health with their patients who are candidates for bariatric surgery.
“These data also emphasize the importance of devising therapies that can counteract fracture risk after gastric bypass,” concluded Yu.