Background: LDL particles differ in size and density. Individuals with LDL profiles that peak in relatively small, dense particles have been reported to be at increased risk of coronary artery disease. We hypothesized that response to coronary disease therapy in such individuals might differ from response in individuals whose profiles peak in larger, more buoyant LDL. We examined this hypothesis in the Stanford Coronary Risk Intervention Project, an angiographic trial that compared multifactorial risk-reduction intervention with the usual care of physicians.
Methods and results: For 213 men, a bimodal frequency distribution of peak LDL density (g/mL) determined by analytical ultracentrifugation was used to classify baseline LDL profiles as "buoyant mode" (density < or = 1.0378) or "dense mode" (density > 1.0378). Coronary disease progression after 4 years was assessed by rates of change (mm/y, negative when arteries narrow) of minimum artery diameter. Rates for buoyant-mode subjects were -0.038 +/- 0.007 (mean +/- SEM) in usual care (n = 65) and -0.039 +/- 0.010 in intervention (n = 56; P = .6). Rates for dense-mode subjects were -0.054 +/- 0.012 in usual care (n = 51) and -0.008 +/- 0.009 in intervention (n = 41, P = .007). Lipid changes did not account for this difference in angiographic response.
Conclusions: Different types of LDL profile may predict different-responses to specific therapies, perhaps because metabolic processes determine both LDL profiles and responses to therapies.