Insulin requirement in elderly patients with non-insulin dependent diabetes mellitus (NIDDM)

Diabetes mellitus in the elderly is mainly of the non-insulin dependent type (NIDDM). A large proportion of such patients are treated with insulin, after many years of therapy with oral hypoglycemic agents (OHA), on the assumption that these lose their efficacy with time. Moreover, many such patients are obese and show preserved insulin release. In the present study 45 obese subjects with NIDDM (14 under good metabolic control and 31 who presented hyperglycemia for at least 3 mo prior to testing) were placed on a strictly hypocaloric diet (800 Kcal/d) for 20 to 24 d. All of these patients had preserved insulin release. At the end of the trial, all the patients presented a significant reduction in body weight and a near normalization of the blood glucose profile, as well as a significant decrease both in the serum cholesterol and triglyceride levels and in the systolic blood pressure. On the basis of these results, insulin and OHA could be reduced in all the patients and suspended in some of these. The decrease in blood glucose levels was the same in all the patients regardless of the length of time that each had suffered from NIDDM. Five non-obese patients were placed on the same regimen, but the daily insulin dose could not be reduced. These data indicate that the majority of obese elderly patients with NIDDM are unnecessarily treated with insulin or with OHA, while diet alone would be sufficient to keep them under good metabolic control.