Lipid, glucose, and insulin interrelationships in normal, prediabetic, and chemical diabetic subjects.

Fasting levels of plasma cholersterol and triglyceride, lipoprotein patterns, and fasting and postintravenous glucose levels of blood glucose, serum insulin, serum growth hormone, and plasma free fatty acids in a genetic potential diabetic population were compared to those in a similar normal control population. THe potential diabetic population was further divided into groups of patients with a normal (prediabetic) or abnormal (chemical diabetic) glucose tolerance test. Although no clear-cut lipid differences were noted, certain trends appeared. More type IV hyperlipoproteinemia was seen in male prediabetic (21%) and male chemical diabetic patients (19%) than in normal male subjects (5%); in female subjects only a few type IV patterns were seen. Type II hyperlipoproteinemia was not seen in any normal subject, but was noted in nearly 9% of those with chemical diabetes. Fasting cholesterol levels correlated better with age than did fasting triglyceride levels in most of the patient groups. Fasting triglyceride levels showed a significant positive correlation with the serum insulin area of the oral glucose tolerance test in the normals wna prediabetic persons, and also showed a significant positive correlation with the blood glucose area of the prediabetic and chemical diabetic patients. It is suggested that a normal relationship between triglyceride concentration and insulin response to glucose is lost in chemical diabetes. Sex differences were also noted in the inslin response and the insulin-glucose relationships during the oral glucose tolerance test, with normal menstruation women showing a significantly lower insulin-glucose relationship than the age-related men.