Abstract 18939: Impact of LDL Pattern on Risk for CHD in the Framingham Offspring Population

Abstract

Introduction: Low-density lipoprotein (LDL) particles that are small and dense are characteristic of pattern B. It has been assumed that such particles are more atherogenic than larger, more buoyant particles indicative of LDL pattern A. Additionally, there is evidence from observational studies to support LDL pattern B as an emerging risk factor for coronary heart disease (CHD) with the incidence of CHD increasing as the proportion of type B to type A LDL particles increases.

Hypothesis: In participants in the Framingham Offspring Cohort Study (FOCS), LDL pattern B is a significant and independent risk factor for incident CHD (inclusive of coronary death, myocardial infarction, coronary insufficiency, and angina pectoris) and hard CHD (CHD endpoints exclusive of angina pectoris).

Methods: Vertical auto profile measurements were performed on 819 men and women on no lipid-modifying therapy as part of an exploratory analysis of the FOCS. The relationship between increasing LDL pattern type (A, A/B, and B) and 12-year risk for CHD and hard CHD was quantified using multivariable Cox proportional hazard regression for two models adjusted for known Framingham risk factors (model 1 adjusts for age, sex, systolic blood pressure and use of antihypertensives, prevalent diabetes, and smoking; model 2 adjusts for model 1 risk factors, HDL-C, and total cholesterol).

Results: LDL pattern B is a statistically significant (p < 0.05) independent risk factor for 12-year incident CHD with hazard ratios of approximately 1.4 in models 1 and 2. For incident hard CHD, LDL pattern B is a more significant risk factor with hazard ratios greater than two and p < 0.005 across both models. There was no effect modification by sex (p > 0.7).

Conclusions: In this exploratory analysis, LDL pattern B is an independent risk factor for CHD and hard CHD after controlling for known Framingham risk factors in men and women on no lipid-lowering therapy.