The endogenous insulin secretion capacity of 171 insulin-treated middle-aged persons with diabetes (81 men, 90 women) of the Kuopio University Central Hospital district (population 250,000), East Finland, was measured by the C-peptide response to glucagori. The prevalence of insulin deficiency among initially non-insulin-dependent diabetic (NIDDM) individuals was calculated on the basis of those who were initially treated with diet or oral drugs and 3 yr or more after diagnosis had been treated with insulin and were insulin deficient in this study. The prevalence of complete insulin deficiency (postglucagon C-peptide undetectable) was among initially NIDDM individuals of the same region, 0.7% in menand 1.2% in women. Using the postglucagon C-peptide level of 0.20 nmol/L as a cut-offpoint, the prevalence of insulin deficiency was 2.0% in men and 1.9% in women and, on thebasis of C-peptide level of 0.60 nmol/L, the prevalence of insulin deficiency was 3.5% in men and 2.7% in women. Our data suggest that the deterioration of insulin secretion capacity in NIDDM to the level that leads to insulin dependency occurs less often than has been previously suggested.

This content is only available via PDF.