Nutritional effect of oral supplement enriched in beta-hydroxy-beta-methylbutyrate, glutamine and arginine on resting metabolic rate after laparoscopic gastric bypass.

BACKGROUND

Weight regain that begins 12-18 months after laparoscopic gastric bypass has been attributed to changes in resting metabolic rate (RMR), which is largely determined by lean body mass (LBM). An oral supplement containing beta-hydroxy-beta-methylbutyrate, glutamine, and arginine (HMB/Glu/Arg) has helped to restore LBM in cachexia due to cancer and in critically ill trauma patients. The objective of this study was to evaluate the effect of oral HMB/Glu/Arg on LBM and RMR following laparoscopic gastric bypass (LGB).

METHODS

Patients who underwent LGB were randomized to receive 24 g of HMB/Glu/Arg dissolved in water twice daily for 8 weeks or to receive no supplement. Weight loss, LBM, and RMR were assessed preoperatively, 2 and 8 weeks postoperatively. LBM was determined by dual emission x-ray absorptiometry (DXA) and RMR was measured by indirect calorimetry.

RESULTS

Thirty patients were enrolled: 80% white; 20% African American; 96.7% women; mean age 46.9±8.4 years; mean weight 113.4±11.6 kg; and mean body mass index (BMI) 43.3±4.1 kg/m2. The experimental and control groups included 14 and 16 patients, respectively, and there was no difference in baseline demographics and characteristics between the two groups. At 8 weeks, weight, BMI, LBM, and RMR significantly decreased by 15.7±2.5 kg, 6.0±1.0 kg/m2, 7.8±4.0 kg, and 290.6±234.9 kcal/day, respectively (P<0.0001 for each variable). However, when comparing these changes between the two groups, no statistical significance was observed.

CONCLUSIONS

There is a significant decrease in weight, BMI, LBM, and RMR in all subjects after LGB, and these changes were not affected by the use of HMB/Glu/Arg. Potential preservation of LBM as a result of HMB/Glu/Arg requires further investigation. However, its consumption (78 calories per serving) did not adversely affect weight loss in the experimental group.