COMPARISON OF APOLIPOPROTEIN(a) PHENOTYPES IN CHINESE WOMEN BETWEEN lIVING IN SINGAPORE AND AUSTRALIA

ZhuoWei Xiong¹, YeanLeng Lim¹, KoonHou Mak¹, Beryl M Biegler (Deceased)², Nicholas D.H. Balazs², YiShen Junie H'NG¹, SimLeng Tien³, SingZern Fong³, TianHai Koh¹, Charles Chan¹, DingWei Xiong², Bridget H-H Hsu-Hage⁴, Dong Wang¹, HeMing Wei¹, Subroto Chatterjee, Mark L Wahlqvist⁵, 1 National Heart Centre, Singapore, 2 Monash Medical Centre, Australia, 3 Singapore General Hospital, Singapore, 4 Melbourne University, Australia, 5 Asia Pacific Health & Nutrition Nutrition Centre, Monash University, Australia.

Objective: Elevated lipoprotein(a) [Lp(a)] concentration with small molecular weight apolipoprotein(a) [apo(a)] phenotypes is now considered major risk factor for coronary heart disease (CHD). Levels of Lp(a) are known to increase post-menopausal women, however, apo(a) phenotypes has not been evaluated yet before and after menopause in Australia and Singapore populations. The authors determined Lp(a) phenotypes and lipoprotein parameters in pre-and post-menopausal women in the two countries.

Methods and Results: We determined Apo(a) phenotypes in 72 women in Singapore Chinese (ages ranged 29-70 years with a mean of 46±1 years) in comparison to 276 Chinese women (ages ranged 23-80 years with a mean of 43±1 years) in Australia. 38 of post-menopausal Singapore women (mean age 51±1 years) and 93 post-menopause in Australia (mean age 57±1 years) were studied. The phenotypes S3, S4, S1S2, S1S3, S1S4, S2S3, S2S4, S3S4, BS3 and BS4 occurred frequently in the Chinese women in the two countries. The Singapore Chinese women had the highest frequency of S3S4 phenotypes, while the highest frequency in Australia was the S4 phenotypes.

Mean Lp(a) levels were higher in post-menopause than in pro-menopausal women in both large and small molecular weights apo(a) phenotypes, although median Lp(a) concentrations were higher in after than before menopause only in small molecular weight apo(a) phenotypes.

Conclusions: These findings imply that the studies of apo(a) phenotypes can pool results from premenopausal and postmenopausal women and that women hormonal interventions are more likely to reduce CHD risk factor Lp(a) levels in aged women.