A Pilot, Randomized Study in Women of Nutrition-Related Clinical Chemistry at 6 Weeks after Roux en Y Gastric Bypass: Comparison of Two Nutrition Support Plans

Abstract

Background: The current pilot study tested a twofold hypothesis: some nutrition-related chemical measures change by 6 weeks after Roux en Y Gastric Bypass (RNYGB); one of two nutrition support plans will prevent chemical signs of nutrition problems at 6 weeks better than the other. After RNYGB, nutrition support should begin right away. However, studies on nutritional status mostly examine subjects much later. In addition, little attention has been paid to optimizing nutrition support plans.

Methods: Premenopausal females scheduled for RNYGB were given either a commercially available meal replacement product (2 servings/day) + other supplements or just a new meal replacement (2 servings/day). The latter included some nutrient versions that might enhance absorption. Blood and urine samples were taken before and 6 weeks after surgery.

Results: In both groups, plasma vitamin D and B₁₂ did not change, plasma osteopontin and vascular endothelial growth factor rose, while plasma retinol binding protein and a bone resorption marker declined. Copper status changes differed between groups based on plasma ceruloplasmin. Iron status improved in both groups (ferritin to c-reactive protein ratios). With the new formulation, magnesium status may have improved, urinary potassium rose, and blood sugar fell. In the other group, a liver damage marker increased, while homocysteine decreased.

Conclusions: Nutrition-related parameters showed varying trends 6 weeks after RNYGB. Some of the trends were affected by the type of nutritional support provided.

Keywords: Bariatric; Gastric bypass; Minerals; Nutritional status; Vitamins.