Hyperglycemia and plasma lipid levels: covariations in insulin-dependent diabetes.

Longitudinal relationships of plasma lipids with parameters of blood glucose control were studied in 124 young insulin-dependent diabetic patients who had multiple, simultaneous determinations of these parameters during a 1-yr period. Fluctuations in hemoglobin A1, a cumulative measure of blood glucose control, correlated with fluctuations in total cholesterol (r = 0.19, P less than 0.001) and low-density lipoprotein-cholesterol (r = 0.17, P less than 0.001). Similarly, fluctuations in fasting blood glucose correlated with those in total cholesterol (r = 0.20, P less than 0.001), very low-density lipoprotein-cholesterol (r = 0.13, P = 0.002), and total triglyceride (r = 0.23, P less than 0.001). These data indicate covariation between plasma lipid and blood glucose control parameters and suggest that poor blood glucose control contributes to the excess risk of coronary heart disease in insulin-dependent diabetes mellitus.