Revisional Roux-en-Y gastric bypass after sleeve gastrectomy impacts bone health in postmenopausal women.

UNLABELLED: Revisional Roux-en-Y gastric bypass after sleeve gastrectomy may worsen bone loss compared to primary surgery. This study found significantly lower hip and femoral neck bone density despite similar body composition. These results emphasize the need for careful bone monitoring in patients undergoing revisional bariatric procedures. BACKGROUND: Bariatric surgery effectively treats severe obesity but adversely affects bone health, particularly after malabsorptive procedures such as Roux-en-Y gastric bypass (RYGB). While skeletal consequences of primary RYGB are well-documented, data on revisional RYGB following sleeve gastrectomy (SG) are scarce. This study aimed to assess the impact of revisional RYGB on bone mineral density (BMD), body composition, and related biochemical parameters. METHODS: In this single-center, cross-sectional study, postmenopausal women who underwent primary or revisional RYGB were evaluated using dual-energy X-ray absorptiometry (DXA). Two groups were defined: primary RYGB (n = 97) and revisional RYGB after SG (n = 23). Demographics, comorbidities, osteoporosis risk factors, BMD at lumbar spine, femoral neck, and total hip, and body composition were collected. BMD and body composition were analyzed both unadjusted and adjusted for age, BMI, and time since surgery. RESULTS: Baseline characteristics, BMI, comorbidities, and osteoporotic risk factors were similar between groups. Unadjusted femoral neck BMD and T-scores were significantly lower in the revisional RYGB group (BMD: 0.693 ± 0.098 vs. 0.761 ± 0.114 g/cm2, p = 0.011; T-score: -1.4 ± 0.8 vs. -0.9 ± 0.9, p = 0.016), whereas lumbar spine and total hip BMD were comparable. After adjustment, the adjusted mean (95% CI) of total hip BMD (0.834 (0.786 to 0.882) vs. 0.899 (0.877 to 0.921) g/cm2, p = 0.017) and that of femoral neck BMD (0.682 (0.636 to 0.729) vs. 0.763 (0.742 to 0.785) g/cm2, p = 0.003) remained significantly lower in the revisional group. Body composition did not differ between groups. CONCLUSIONS: Revisional RYGB after SG is associated with lower BMD at femoral sites compared with primary RYGB, even after adjusting for age, BMI, and time since surgery, while body composition is similar. These findings highlight the need for targeted bone health monitoring and management in patients undergoing revisional bariatric procedures.