Roux-en-Y gastric bypass (RYGB) is associated with a higher risk for nonvertebral fractures compared with adjustable gastric banding (ABG), according to study results published in JAMA Surgery.
Recent studies have shown that bariatric procedures, and RYGB in particular, can be associated with bone loss and decline in bone density and microarchitecture. AGB is a less invasive procedure, and most studies have not shown significant bone loss after this procedure. The researchers aimed to assess the fracture risk after RYGB compared with AGB.
The retrospective cohort study was based on Medicare claims data from between January 1, 2006, and December 31, 2014. Study participants were adults aged ≥21 years with body mass index ≥40 kg/m2 who were undergoing RYGB (29,624 patients) or AGB (12,721 patients). The primary outcome was incidence of nonvertebral fracture (humerus, wrist, hip, or pelvis).
During an average follow-up period of 3.3 years for the RYGB group and 3.9 years for the AGB group, there were 658 nonvertebral fracture events among the study participants. The overall incidence rate for any fracture was 6.6/1000 person-years for patients after RYGB compared with 4.6/1000 person-years for AGB recipients (adjusted hazard ratio [HR], 1.73; 95% CI, 1.45-2.08).
Skeletal site-specific analyses demonstrated an increased fracture risk at the hip (HR, 2.81; 95% CI, 1.82-4.49), wrist (HR, 1.70; 95% CI, 1.33-2.14), and pelvis (HR, 1.48; 95% CI, 1.08-2.07).
This increased risk was maintained in patients ≥65 years old, with an incidence rate for any fracture of 9.9/1000 person-years in patients after RYGB and 5.3/1000 person-years in patients after AGB. In this older group of patients, RYGB was associated with a 75% increased risk for any nonvertebral fracture (HR, 1.75; 95% CI, 1.22-2.52), a 151% increased risk for hip fracture (HR, 2.51; 95% CI, 1.25-5.93), and a 65% increased risk for wrist fracture (HR, 1.65; 95% CI, 1.25-2.77) compared with older patients who received AGB.
Sensitivity analyses, using a propensity score-matched cohort of 12,183 pairs of RYGB and AGB recipients, demonstrated similar findings, with an increased risk for nonvertebral fracture in patients after RYGB compared with AGB (HR, 1.68; 95% CI, 1.38-2.05).
The researchers acknowledged some of the limitations of the study, including possible uncontrolled confounders, exclusion of vertebral fracture as an outcome because of inability to accurately identify these fractures, and not including cases of sleeve gastrectomy, which has eclipsed RYGB in popularity and may also be associated with adverse skeletal effects.
“[A]lthough bariatric surgery is associated with myriad health benefits, increased fracture risk is an important factor to discuss with patients seeking RYGB,” concluded the investigators.
Yu EW, Kim SC, Sturgeon DJ, Lindeman KG, Weissman JS. Fracture risk after Roux-en-Y gastric bypass vs adjustable gastric banding among Medicare beneficiaries [published online May 15, 2019]. JAMA Surg. doi:10.1001/jamasurg.2019.1157