Hormonal and metabolic aspects of diabetes mellitus in the elderly

Abstract

Hormonal and metabolic characteristics of diabetes mellitus in the elderly were investigated in the following groups; elderly DM subdivided into obese DM and non-obese DM, elderly non-DM subdivided into obese and non-DM and non-obese non-DM, adult DM and adult non-DM. Responses of plasma glucose, insulin and glucagon during oral glucose tolerance test (OGTT), arginine tolerance test (ATT) and intravenous glucose tolerance test (IVGTT) were measured individually and the daily urinary C-peptide excretion (U-CRP), fasting plasma levels of free fatty acid (FFA), triglyceride (TD), total cholesterol (TC) and HDL-cholesterol (HDL-C) were also measured. In comparison with adults, insulin responses in IVGTT and ATT in elderly non-DM were low but not in OGTT. It was noteworthy that glucagon response during OGTT in elderly DM was considerably lower than adult DM, probably due to factors other than insulin deficiency. Comparing elderly DM and elderly non-DM, the initial response of insulin in OGTT was found to be low in elderly DM but not in total response. In the comparison between the obese and the non-obese, higher insulin levels in elderly obese DM than in elderly non-obese DM during OGTT, IVGTT and ATT were observed, implying decreased insulin sensitivity. This difference, however, was not apparent between elderly obese non-DM and non-obese non-DM. A good correlation between U-CPR and the response of plasma insulin in OGTT was shown even in the elderly but not between U-CPR and that of plasma insulin in IVGTT.(ABSTRACT TRUNCATED AT 250 WORDS)