Serum cholesterol is a risk factor for myocardial infarction in elderly men and women: the Rotterdam Study.

OBJECTIVE To investigate the associations of serum total and HDL cholesterol with the risk of myocardial infarction in men and women of 55 years and over. DESIGN The Rotterdam Study is a population-based prospective cohort study. In total 2453 men and 3553 women of 55 years and older were included in this study. The mean duration of follow-up was 4 years. MAIN OUTCOME MEASURES Relative risks were estimated with Cox's proportional-hazard analysis. Cholesterol was analysed as a continuous variable and in sex-specific quartiles. RESULTS In subjects aged 55 years and older the relative risk of myocardial infarction was 1.9 in men (95% confidence interval 1.1-3.3) and 3.2 in women (1.5-6.4) in the highest compared to the lowest serum total cholesterol quartile (Q4 vs. Q1). In men and women of 70 years and older, total cholesterol remained an important risk factor for myocardial infarction (Q4 vs. Q1 relative risk 3.2; 1.3-7.7 and 2.9; 1.3-6.6, respectively). For HDL cholesterol, the relative risk in the highest compared to the lowest quartile (Q4 vs. Q1) was 0.5 in men (0.3-0.9) and 0.4 in women (0.2-0.9). HDL cholesterol was a weaker predictor in men after the age of 70 (Q4 vs. Q1 0.8; 0.3-2.1). In women of 70 years and older the relative risk was also not significant (Q4 vs. Q1 0.6; 0.3-1.3), although the trend over the quartiles was still significant. CONCLUSION Serum total cholesterol remains an important risk factor for myocardial infarction in men and women aged 70 years and older, whilst HDL cholesterol at older age remains important in women only.