Effect of Carbohydrate Restriction in Patients with Hyperinsulinemic Hypoglycemia after Roux-en-Y Gastric Bypass

Hyperinsulinemic hypoglycemia is a rare complication of Roux-en-Y gastric bypass (RYGB) surgery. Meals with a high carbohydrate (carb) content and high glycemic index (GI) may provoke these hypoglycemic attacks. The aim of this study is to assess the effects of reducing meal carb content and GI on glycemic responses in patients with post-RYGB hypoglycemia. Fourteen patients with post-RYGB hypoglycemia underwent two meal tests: a mixed meal test (MMT) with a carb content of 30 g and a meal test with the low GI supplement, Glucerna SR 1.5A (R) (Glucerna meal test (GMT)). Plasma glucose and serum insulin levels were measured for a period of 6 h. Peak glucose levels were reached at T (30) during GMT and at T (60) during MMT, and they were 1.5 +/- 0.3 mmol/L lower during GMT than during MMT (7.5 +/- 0.4 vs 9.0 +/- 0.4 mmol/L, P < 0.005). GMT induced the most rapid rise in plasma insulin: at T (30) plasma, insulin was 30.7 +/- 8.5 mU/L higher during GMT than during MMT (P < 0.005). None of the carb-restricted meals induced post-prandial hypoglycemia. A 30-g carb-restricted meal may help to prevent post-prandial hypoglycemia in patients with post-RYGB hypoglycemia. The use of a liquid, low GI, supplement offers no additional advantage.