Bone Turnover Markers After Standard and Distal Roux-en-Y Gastric Bypass: Results from a Randomized Controlled Trial

BACKGROUND

Roux-en-Y gastric bypass is associated with increased risk of bone fractures. Malabsorptive procedures may be associated with secondary hyperparathyroidism and detrimental effects on bone health. We aimed to compare the effects of standard and distal gastric bypass on bone turnover markers 2 years after surgery.

METHODS

Patients with body mass index (BMI) 50-60 kg/m² (n = 113) were randomized to standard or distal gastric bypass, 105 patients (95%) completed 2-year follow-up. Serum C-terminal telopeptide of type I collagen (CTX-1), procollagen type I N-propeptide (PINP), and bone-derived alkaline phosphatase (BALP) was measured at baseline and up to 2 years after surgery. ANCOVA and linear mixed models were used to compare groups.

RESULTS

The levels of bone turnover markers increased significantly in both groups, with no statistically significant difference between groups. Two years after standard and distal gastric bypass mean (SD) CTX-1 were 0.81 (0.32) and 0.83 (0.31) μg/L (p = 0.38), mean PINP was 77.6 (23.2) and 77.7 (29.3) μg/L (p = 0.42), and BALP 47.9 (21.9) vs. 50.7 (19.6) μg/L (p = 0.38), respectively. Multiple linear regression analyses showed that PINP and BALP correlated positively (p = 0.01 and p < 0.001) with PTH, but only BALP was significantly higher in patients with secondary hyperparathyroidism (p = 0.001). Type of surgery, vitamin D serum concentrations, and 2-year BMI were all independently associated with PTH levels.

CONCLUSION

A comparable increase in bone turnover markers 2 years after standard and distal gastric bypass was observed. There was a higher prevalence of secondary hyperparathyroidism after distal gastric bypass, but this did not impact bone turnover markers.

TRIAL REGISTRATION

Clinical Trials.gov number NCT00821197.

Long-term outcomes after biliopancreatic diversion with and without duodenal switch: 2-, 5-, and 10-year data

BACKGROUND

There are minimal long-term data on biliopancreatic diversion (BPD) with or without duodenal switch (BPD/DS).

OBJECTIVES

To investigate the long-term weight loss, co-morbidity remission, complications, and quality of life after BPD and BPD/DS.

SETTING

An academic, university hospital in the United States.

METHODS

We conducted a retrospective review of patients who underwent BPD or BPD/DS between 1999 and 2011. Outcomes included weight loss measures at 2, 5, and 10-15 years postoperatively; co-morbidity remission; long-term complications; nutritional deficiencies; and patient satisfaction.

RESULTS

One hundred patients underwent BPD (34%) or BPD/DS (64%). Mean preoperative body mass index (BMI) was 50.2 kg/m². Mean follow up was 8.2 years (range: 1-15 yr) with 72% of eligible patients in active follow up at 10-15 years postoperatively. Excess weight loss (EWL) was 65.1% at 2 years, 63.8% at 5 years, and 67.9% at 10-15 years. Approximately 10% higher %EWL was achieved for those with preoperative BMI<50 kg/m² versus≥50 kg/m² and patients who underwent BPD/DS versus BPD. Although co-morbidities improved, 37% of patients developed long-term complications requiring surgery. There were no 30-day mortalities; however, there was one mortality from severe malnutrition. Nutritional deficiencies in fat-soluble vitamins, anemia, and secondary hyperparathyroidism were common. Overall, 94% of patients reported satisfaction with their choice of surgery.

CONCLUSION

This clinical experience supports the long-term positive safety profile and efficacy of BPD and BPD/DS at a single U.S. center. Higher levels of excess weight loss are achieved by patients with a lower preoperative BMI and BPD/DS. Although nutritional deficiencies and postoperative complications are common, patient satisfaction remains high.