Basal and postprotein insulin and glucagon levels during a high and low carbohydrate intake and their relationships to plasma triglycerides

The effects of acute and chronic differences in the carbohydrate content of the diet on plasma insulin, glucagon, insulin glucagon molar ratio (I/G), and triglycerides were studied. Acute effects were studied by varying the carbohydrate content of a single test meal, while chronic effects were determined by varying the carbohydrate content of the diet for a week. A test meal containing 0.6 gm of gelatin per kilogram plus 0.6 gm per kilogram of glucose resulted in much higher levels of insulin and I/G (p<0.005), lower glucagon levels (p<0.05), and slightly higher triglycerides (N.S.) than did a meal of 1.2 gm per kilogram of gelatin alone. One week of a 12 gm carbohydrate, 2870 calorie diet lowered insulin (p<0.001), I/G (p<0.05), and triglycerides (p<0.001) and increased glucagon (N.S.), whereas a 390 gm carbohydrate, 2784 calorie intake significantly increased insulin, I/G, and triglycerides (p<0.005) and lowered glucagon (p<0.02) within two days; even greater changes in hormones were observed on a 510 gm carbohydrate intake. Of those patients in whom a high carbohydrate intake induced a triglyceride rise of at least 40 mg per deciliter, a significant correlation between the change in I/G and the change in triglycerides was noted (r=0.82; p<0.01). The results are compatible with but do not prove the proposal that pancreatic α and β cells play a mediating role in carbohydrate induction of hyperlipidemia.