Gender and age differences in the distribution of the HDL subclasses among the Chinese population

Background and aims: to analyze the gender and age differences in the distribution of the high-density lipoprotein (HDL) subclasses among the Chinese population, and to clarify the mechanism of these changes. Methods and results: the apoA-I contents of the plasma HDL subclasses were determined by 2-DE coupled with immunodetection in 324 men (including 186 normolipidemic subjects) and 186 women (including 114 normolipidemic subjects). The contents of pre beta(1)-HDL and HDL3 (HDL3c, HDL3b, HDL3a) were significantly lower, whereas the contents of HDL2a and HDL2b were higher for women than for men in the <50 years age group. Moreover, the contents of pre beta(1)-HDL and HDL3 were higher for female subjects; the HDL2a and HDL2b contents were lower for both female and male subjects in the 50-59, 60-69, and >= 70 years age groups versus the subjects of the same gender in the <50 years age group. When compared to the normolipidemic premenopausal women, pre beta(1)-HDL, HDL3b, and HDL3a increased while HDL2b decreased significantly in normolipidemic men and postmenopausal women. Conclusions: the contents of the large-sized HDL particles HDL2b were higher, but the contents of the small-sized HDL particles (pre beta(1)-HDL, HDL3b, HDL3a) were lower for women versus men in the <50 years age group. Meanwhile, the gender difference in distribution of the HDL subclass narrowed obviously with advancing age. Moreover, the characteristics of the HDL subclass distribution profile for the normolipidemic postmenopausal women resembled those for the normolipidemic men.