Influence of food on glycemia, insulin, C-peptide and glucagon levels in diabetic patients treated with antidiabetic metformin at steady-state.

Seventeen diabetic patients (5 males and 12 females) treated with long-term metformin therapy received their morning dose after an overnight fast or after one of four types of breakfast: low protein, low fat, low carbohydrate or standard. Mean (+/- SD) and median areas under the serum concentration curves (AUC), maximum concentrations (Cmax) and time to reach the maximum concentrations (tmax) were calculated for the major biological parameters (glycemia, C-peptide, insulin and glucagon levels). None of the diets were bioequivalent to the fasting condition and only the low carbohydrate diet gave comparable results. A strong relationship was found between the carbohydrate intake (in g) and the AUC of the various markers except glucagon.