P5323HDL-C and all-cause mortality in a high-risk population: impact of LDL-C

Abstract

Abstract Background Previous studies have shown increased cardiovascular (CV) risk with both high (>60mg/dl) and low concentrations of high-density lipoprotein cholesterol (HDL-C). The effect of elevated HDL-C levels (>60mg/dL) at differing LDL-C concentrations on outcomes is unknown. Purpose To study the relationship between elevated HDL-C levels (>60mg/dl) in relation to LDL-C concentration (greater vs less than 70mg/dL) and adverse CV outcomes in an at-risk population. Methods Participants included 5,746 individuals (mean age 63.3±12.4 years, 35% female, 23% African American) enrolled in the cardiovascular biobank. Individuals were stratified by HDL-C categories (<30, 31–40, 41–50, 51–60 and ≥60 mg/dL) and LDL-C categories (≥70 and <70 mg/dL). A Cox proportional hazards model was used to examine the association between HDL-C and adverse outcomes, with HDL-C 41–50 mg/dL as the reference group. All models were adjusted for age, race, sex, body mass index, hypertension, smoking, triglycerides, heart failure history, myocardial infarction (MI) history, diabetes, angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker use, beta blocker use, statin use, aspirin use, estimated glomerular filtration rate, obstructive coronary artery disease. Results Over a median follow-up of 6.2 years (25th-75th percentiles = 3.3–8.0 years), a total of 286 MIs, 691 CV deaths and 1,093 all-cause deaths occurred. Individuals with HDL-C ≥60 mg/dL (n=632) had an increased risk of all-cause mortality with an LDL-C ≥70mgdL (HR 1.59; 95% CI=1.10–2.29, p=0.013) after adjustment for the aforementioned variables. This association was not statistically significant with LDL-C <70mg/dL (HR 1.16; 95% CI 0.60–1.21, p=0.66). There was no statistically significant difference for CV death or MI at elevated HDL-C in either group. Conclusion Elevated HDL-C levels is associated with increased all-cause mortality with an LDL-C ≥70mg/dL, though does not appear to be associated with worse outcomes when LDL-C is <70mg/dL.