Lipoprotein(a)[Lp(a)], an independent risk factor for athrosclerosis, consist of low density lipoprotein like particle and specific glycoprotein, apolipoprotein(a). The levels of Lp(a) are mainly determined by the genetic pleomorphism of apolipoprotein(a) and has been though not to be influenced by age, sex and other biochemical parameters. Recent reports have shown that the concentrations of Lp(a) are correlated with age in women. The purpose of this study was to invastigate the association of Lp(a) concentration with sex and age.

The concentrations of Lp(a) were measured in 3,707 women and 389 men, free of diseases and medications known to affect the lipid levels. Plasma Lp(a) concentration were measured by commercial radioimmunoassay kit and other lipid profiles by conventional method.

In female, median Lp(a) concentration increased with age till the early sixth decade (P=.0000) and then decreased. If peri- and postmenopausal women were excluded in the fifth decades, the relation between age and Lp(a) disappeared. In male, Lp(a) concentration were not associated with age. Median Lp(a) concentrations were higher in females than in males in the fifth(p=.0039) and the sixth decades(p=.0007), The difference became negligible after the exclusion of peri- and postmenopausal woman in the fifth decade.

The concentrations of Lp(a) were corrected with age only in female. Females had higher levels than males in the fifth and the sixth decades. The relations are thought to be nither due to aging process nor sex but due to postmenopausal increase of Lp(a).