Low-density lipoprotein particle size and coronary artery disease in a childhood-onset type 1 diabetes population

Low-density lipoprotein (LDL) cholesterol has been widely recognized as a s trong predictor of coronary artery disease (CAD). Recently, studies have ex amined the influence of LDL particle size (an integral part of the insulin resistance syndrome) on the development of CAD in the general population. T his report examines the correlates of LDL particle size and its association with CAD in a type 1 diabetes population. We evaluated the interrelationsh ips between LDL particle size and the presence of CAD in a cohort of childh ood-onset type 1 diabetic subjects using the Pittsburgh Epidemiology of Dia betes Complications (EDC) study. LDL particle size was measured in 337 subj ects (mean age, 35.6 years; mean diabetes duration, 27.2 years) who underwe nt the 8-year follow-up examination. LDL particle size was determined by ve rtical polyacrylamide gel (2% to 16%) electrophoresis. Subjects with the sm all dense LDL particle phenotype (<235.5 nmol/L) had a longer diabetes dura tion, higher cholesterol, triglyceride, LDL, fibrinogen, waist to hip ratio (WHR), and hemoglobin A(1) (HbA(1)), and lower high-density lipoprotein (H DL) cholesterol compared with subjects with the large LDL particle phenotyp e (>257 nmol/L). Males were also more likely to have an increased body mass index (BMI) and CAD, while females were more likely to have hypertension a nd a family history of type 2 diabetes (a potential marker of insulin resis tance and CAD risk). The odds ratio ([OR] 95% confidence, interval [CI]) us ing logistic regression analysis for LDL particle size in association with CAD was 0.79 (0.60 to 1.04). Multivariate modeling indicated that the durat ion of type 1 diabetes, depressive symptomatology, and triglycerides were i ndependently associated with the presence of CAD. We conclude that although small dense LDL particle size is associated with CAD in our type 1 diabete s population, its borderline association can largely be explained by the tr iglyceride concentration. However, as in the general population, LDL partic le size is associated with many elements of the insulin resistance syndrome , including a family history of type 2 diabetes, and is likely an important element in the contribution of insulin resistance to the development of CA D in type 1 diabetes. Copyright (C) 1999 by W.B. Saunders Company.