Background: While a positive relation between serum cholesterol and the risk of myocardial infarction has been consistently reported, the association between serum cholesterol and the risk of ischemic stroke lacks consistency. To further investigate the strength of cholesterol as a risk factor for myocardial infarction and stroke we conducted a comparative study.
Methods: A case-control study was conducted from 1990 to 1992. A network of 21 hospitals in Abruzzo, southern Italy, was created. First, computerized tomography scans confirmed ischemic stroke patients (230 with median age: 64; range: 31-69 years) and 230 sex- and age-matched controls with acute disorders unrelated to known cardiovascular risk factors. Acute myocardial infarction patients (513) and 513 matched controls were simultaneously recruited for a parallel study comparison. Total serum cholesterol concentration was measured within the first 48 hr following admission and the response to a structured questionnaire was evaluated.
Results: The mean (standard deviation) serum cholesterol level was 220.7 mg/dl (50.9) among stroke patients and 201.5 mg/dl (41.6) among controls (P < 0.0001). Compared with the lowest quintile (< 160 mg/dl), the odds ratio of ischemic stroke for patients in the highest quintile (> 240 mg/dl), after simultaneous adjustment for other potentially confounding covariates, was 2.6 (95% confidence interval: 1.4-4.8). A significant linear trend in risk was found (chi 2 1 df = 7.27, P < 0.01). Within each total serum cholesterol quintile, adjusted odds ratios for myocardial infarction were higher than that for ischemic stroke, and a stronger linear trend in risk was found (chi 2 1 df = 21.3, P < 0.0001).
Conclusions: Our data confirm the strong linear relationship between total serum cholesterol and the risk of myocardial infarction and suggest that, at least in our population, cholesterol seems to be an indicator of ischemic stroke risk.