Age- and sex-related differences in lipoproteins containing apoprotein A-I.

We investigated age- and sex-related differences in the structure and composition of two species of lipoproteins that contain apoprotein (apo) A-I (A-I Lp): lipoproteins containing apo A-I and apo A-II (Lp A-I/A-II), and lipoprotein containing apo A-I but no apo A-II (Lp A-I), which were isolated by immunoaffinity chromatography. Sixty normolipidemic volunteers were assigned to one of three groups based on their ages and sexual maturation (Group A, prepubertal; Group B, puberty; and Group C, postpuberty). In A-I Lp, the levels of total cholesterol, cholesteryl ester, phospholipid, and apo A-I were lower in males during puberty and then remained stable. In Lp A-I/A-II, there were no age- or sex-related changes in lipids or in apo A-II. Levels of apo A-I in the females were lower with advance in age, although significant differences were observed only between pre- and postpubertal subjects. In Lp A-I, the levels of total cholesterol, cholesteryl ester, phospholipid, and apo A-I were lower in males during pu...