Effects of Cholesterol and Inflammation-Sensitive Plasma Proteins on Incidence of Myocardial Infarction and Stroke in Men

Abstract

Background — Although cholesterol is a major cardiovascular risk factor, its association with stroke remains controversial. This study explored whether the cholesterol-related incidence of stroke and myocardial infarction is modified by plasma markers of inflammation in a large, population-based cohort with a long follow-up. Methods and Results — Plasma cholesterol and 5 inflammation-sensitive plasma proteins (ISP) (fibrinogen, α ₁ -antitrypsin, haptoglobin, ceruloplasmin, and orosomucoid) were determined in 6063 healthy men, 28 to 61 years of age. The incidence of stroke, cardiac events (fatal and nonfatal), and cardiovascular deaths was compared between groups defined by levels of cholesterol and ISP. Mean follow-up was 18.7 years. High ISP level was defined as 2 to 5 ISP in the top quartile. High cholesterol was associated with higher levels of ISP. Hypercholesterolemia (≥6.5 mmol/L, 251 mg/dL) was associated with an increased incidence of ischemic stroke and cardiac events and with a reduced incidence of intracerebral hemorrhage. The ISP levels modified these associations. After risk factor adjustment, men with hypercholesterolemia and high ISP levels had a significantly higher risk of cardiovascular death (relative risk [RR]=2.4; CI, 1.8 to 3.3), cardiac events (RR=2.3; CI, 1.8 to 3.0), and ischemic stroke (RR=2.1; CI, 1.4 to 3.3) than men with normal cholesterol and low ISP levels. In the absence of high ISP levels, hypercholesterolemia was associated with a moderately higher risk of cardiovascular death (RR=1.4; CI, 1.0 to 2.0) and cardiac events (RR=1.5; CI, 1.2 to 1.9) but not significantly with ischemic stroke (RR=1.25; CI, 0.8 to 2.0). Conclusions — Hypercholesterolemia is associated with high plasma levels of ISP. These proteins increase the cholesterol-related incidence of cardiovascular diseases. In the absence of elevated ISP levels, no statistically confirmed association was found between hypercholesterolemia and ischemic stroke.