EFFECT OF 24 HOURS OF STARVATION ON PLASMA-GLUCOSE AND INSULIN CONCENTRATIONS IN SUBJECTS WITH UNTREATED NON-INSULIN-DEPENDENT DIABETES-MELLITUS

Adherence to a low calorie diet often results in a decrease in blood g lucose concentration in persons with non-insulin-dependent diabetes me llitus (NIDDM). Whether this is due to the resultant weight loss or to a decrease in caloric intake has been uncertain. We have obtained dat a previously that indicated a very short-term reduction in caloric int ake (5 hours) resulted in a significant decrease in plasma glucose con centration in subjects with NIDDM. The purpose of the present study wa s to determine if a further decrease in glucose would occur if the fas t was extended from 5 to 24 hours. Seven male subjects with untreated NIDDM were studied after an 11-hour overnight fast. For the subsequent 24-hour period, subjects were given only water. Blood was obtained fo r glucose, insulin, C-peptide, triglycerides, nonesterified fatty acid s (NEFA) alpha amino acid nitrogen, urea nitrogen, and glucagon at hou rly intervals for 24 hours beginning at 8 AM. The amount of glycogen d egraded was calculated based on the potassium balance. Plasma glucose decreased from 158 mg/dl at 8 AM to a nadir of 104 mg/dL at 7 PM. It t hen increased by 30 mg/dL. Corresponding changes occurred in insulin a nd C-peptide. Serum glucagon remained unchanged. Serum alpha-amino aci d nitrogen and urea nitrogen decreased. Triglycerides and NEFA increas ed. The calculated glycogen utilized over this period was approximatel y 167 g, This would provide approximately 700 kcal energy. The elevate d blood glucose concentration in mild to moderately severe untreated N IDDM subjects was normalized following short-term fasting. Plasma insu lin concentrations also decreased to within normal limits. These decre ases were highly significant. Glycogenolysis is an important source of fuel during this period. (C) 1996 by W.B. Saunders Company