Fracture Risk After Bariatric Surgery: A 12-Year Nationwide Cohort Study

Bariatric surgery has been shown to impair bone health. This study aimed to investigate the fracture risk in patients after bariatric surgery versus propensity score-matched controls. The authors used the National Health Insurance Research Database of Taiwan and identified 2064 patients who underwent bariatric surgery during 2001 to 2009. These patients were matched to 5027 obese patients who did not receive bariatric surgery, using propensity score matching accounting for age, sex, Charlson Comorbidity Index, diabetes, hypertension, hyperlipidemia and the year morbid obesity was diagnosed. The authors followed the surgical and control cohorts to death, any diagnosis of fracture, or December 31, 2012, whichever occurred first. Cox proportional hazard regression models were used to calculate relative rates of fractures in the surgical group and control group. At the end of the 12-year study period, there were 183 fractures in the surgical group (mean follow-up 4.8 years) and 374 fractures in the matched control group (mean follow-up 4.9 years). Overall, there was a 1.21-fold [95% confidence interval (CI): 1.02-1.43] significantly increased risk of fracture in the surgical group compared with the control group. Stratified by surgical procedures, malabsorptive procedures showed a significantly higher fracture risk (1.47, 95% CI: 1.01-2.15). The Kaplan-Meier estimated fracture rates were 1.60% at 1 year, 2.37% at 2 years, 1.69% at 5 years, and 2.06% after 5 years for the surgical patients, compared with 1.51%, 1.65%, 1.53%, and 1.42%, respectively, for the matched controls. Adjusted analysis showed a trend towards an increased fracture risk, 1 to 2 years after bariatric surgery. (1.42, 95% CI: 0.99-2.05). Bariatric surgery was significantly associated with an increased risk of fractures, mainly with malabsorptive procedures, with a trend of an increased fracture risk 1 to 2 years after surgery. These results provide further evidence for the adverse effects of bariatric surgery on the risk of fractures.