Lipoprotein composition in diabetes mellitus.

Lipoprotein cholesterol and triglyceride levels have been determined in normal and diabetic Pima Indian women aged 20-35, HDL cholesterol levels were lower, LDL cholesterol levels were higher, and the ratio of HDL cholesterol/LDL cholesterol, a reflection of lipoprotein cholesterol distribution, was lower in the diabetics compared to the normals. VLDL triglyceride levels were also elevated in the diabetics. An analysis of lipoprotein composition suggested that these changes primarily reflect changes in numbers of particles, since lipid composition and lipid/protein ratios were similar in lipoproteins isolated from normals and diabetics. The ratio of ester/free cholesterol in LDL and HDL was lower in normal Pima Indians than in a comparable group of Caucasians, although plasma LCAT activity was not significantly different. The data indicate that diabetes may be associated with shifts in distribution of LDL and HDL, as well as with increases in VLDL.