VERY-LOW-CALORIE DIET (VLCD) - A USEFUL ALTERNATIVE IN THE TREATMENT OF THE OBESE NIDDM PATIENT

Conventional treatment of obese noninsulin dependent diabetes mellitus (NIDDM) patients is often unsatisfactory. In this study the efficacy of Modifast(R), a commercial very low calorie diet (VLCD), was evaluat ed in a population of obese poorly controlled NIDDM patients. The mech anisms of action of VLCD in these patients were also studied by compar ing: (i) Plasma insulin and glucose profiles after a VLCD and an isoca loric mixed meal and (ii) plasma amino acid levels, both at baseline a nd after four weeks of VLCD treatment. A total of 14 obese NIDDM patie nts (M/F 7/7, median body mass index (BMI) 38.7 kg(-2), interquartile range (IQ) 34.7-46.5 kg(-2), waist circumference 116 cm, IQ 106-139 cm , insulin treated 7/14) with poor diabetic control (HbA(1c) 8.6%, IQ 7 .8-10%) were studied. Patients were given a VLCD (425 kcal/day) for 12 weeks. At baseline, VLCD and isocaloric meal tests were performed on consecutive mornings. Fasting plasma amino acid levels were also deter mined at baseline and after 4 weeks of VLCD treatment. Weight, waist c ircumference, HbA(1c), blood pressure, fasting plasma insulin, total c holesterol and triglyceride levels all fell significantly following VL CD treatment. Insulin therapy was able to be ceased in the seven insul in treated patients. Oral hypoglycaemic agent dosage fell from a media n of eight (IQ 6-12) to two (IQ 0-8) tablets per day (P = 0.03) in pat ients initially on this form of therapy. Insulin secretion was higher after VLCD than isocaloric meal (P = 0.04). Fasting plasma alanine lev el fell from 512.0 (IQ 412.0-563.0) to 374.0 (IQ 342-472.0) mu mol/l ( P = 0.04) following VLCD treatment. In conclusion, the short term use of a VLCD is very effective in rapidly improving glycaemic control and promoting substantial weight loss in obese NIDDM patients. Moreover, a VLCD diet increases insulin secretion and reduces substrate for gluc oneogenesis. Thus, VLCD treatment may improve glycaemic control by fac tors more than caloric restriction alone. (C) 1997 Elsevier Science Ir eland Ltd.