DAILY ENERGY-METABOLISM IN PATIENTS WITH TYPE-1 DIABETES-MELLITUS

Objective: We evaluated the daily energy balance and main substrate ut ilization in Type 1 insulin dependent diabetic patients and healthy vo lunteers. Methods: Ten patients with Type 1 diabetes mellitus and eigh t healthy volunteers were studied. Diabetic patients were well control led under intensive insulin treatment (0.6 UI/kg body weight, HbA(1c) = 5.5 +/- 0.7%). During the 30 hours each subject spent in the respira tion chamber VO2, VCO2, respiratory quotient, daily energy intake, 24- hour, day-time, night-time and basal energy expenditure as well as ene rgy expenditure during exercise tar 40% maximal exercise capacity), ma in substrate oxidation (carbohydrates, lipids and proteins) and overal l diet-induced thermogenesis, were measured. The results were correcte d for 24-hour urinary nitrogen loss. Results: Diet-induced thermogenes is, expressed as percent of energy intake, was found to be significant ly lower in diabetic patients than in control subjects (6.69 +/- 1.29% vs 11.8 +/- 4.71% of energy intake, p < 0.05). A negative correlation was found between diet-induced thermogenesis and daily average glycem ia for diabetic patients (r = -0.65, p < 0.01). Energy expenditure dur ing exercise, calculated in terms of net work efficiency, was not diff erent between the two groups. Conclusions: In conclusion, since diet-i nduced thermogenesis is highly correlated with the theoretical cost of glucose storage and since no difference was found in carbohydrate oxi dation, glucose storage in diabetic patients is probably reduced when hyperglycemia occurs. Diabetic patients in good metabolic control are able to perform mild exercise with a work efficiency very similar to t hat of control subjects.