Background: Lipoprotein (a) is an independent risk factor for coronary heart disease, particularly the premature form. However, differences in its effect have been observed between men and women and in different populations.
Subjects and methods: Lipid and non-lipid risk factors were compared (univariate and multivariate analyses) between a group of patients with myocardial infarction aged less than 65 years (n = 33) and those in their siblings (n = 32) and an unrelated healthy control group (n = 45) of the same gender.
Results: No differences were observed between male patients and their siblings. Differences were indeed observed when patients when compared with controls regarding HDL cholesterol (p = 0.001) and lipoprotein(a) (p = 0.002) serum concentrations. Female patients also had lower serum concentrations of HDL cholesterol than their siblings and controls, but non significant differences were observed for lipoprotein (a). The analysis of lipoprotein (a), categorized with respect to the 90th percentile of controls for each gender, showed a significant association with coronary heart disease only for males: crude odds ratio (OR) compared with controls 10.7 (95% CI: 2.1-54.9) and adjusted of 9.9 (95% CI: 1.6-60.7). The strength of this association was smaller and non-significant in women: crude OR 6,4 (95% CI: 0.8-51.8) and adjusted of 3.09 (95% CI: 0.3-47.2).
Conclusions: Lipoprotein (a) concentrations are similar in siblings and increased concentrations in our population are more strongly and clearly association with coronary heart disease in men.