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 cholester ol 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 pears and older were included in th is study. The mean duration of follow-up was 4 years. Main outcome measures. Relative risks were estimated with Cox's proportiona l-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 myocardia l infarction was 1.9 in men (95% confidence interval 1.1-3.3) and 3.2 in wo men (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 choles terol remained an important risk factor for myocardial infarction (Q4 vs. Q 1 relative risk 3.2; 1.3-7.7 and 2.9; 1.3-6.6, respectively). For HDL chole sterol, the relative risk in the highest compared to the lowest quartile (Q 4 vs. Q1) was 0.5 in men (0.3-0.9) and 0.4 in women (0.2-0.9). HDL choleste rol 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 signific ant (Q4 vs. Q1 0.6; 0.3-1.3), although the trend over the quartiles was sti ll significant. Conclusion. Serum total cholesterol remains an important risk factor for my ocardial infarction in men and women aged 70 years and older, whilst HDL ch olesterol at alder age remains important in women only.