Ethnic differences: Is there an Asian phenotype for polycystic ovarian syndrome?

Ethnicity has not been accounted for in the diagnostic criteria for polycystic ovarian syndrome (PCOS). It is increasingly recognised that ethnic differences are likely contributors to the differing manifestations of PCOS. Generally, rates of PCOS may be lower in East Asians. It is clear that East Asians are less hirsute than Caucasians. Hirsutism cut-off thresholds need to be lower in East Asian populations than in Caucasian populations. Despite population-adjusted scoring, Caucasians have higher hirsutism rates among patients diagnosed with PCOS. Rates of hyperandrogenaemia do not appear to differ among PCOS subjects, although serum androstenedione appeared to be higher in Caucasians in one study. Interestingly, higher prevalence of the polycystic ovarian morphology has been reported in East Asian PCOS populations than in Caucasian PCOS subjects. Hence, there is a need for comparative studies across different ethnicities to establish whether epidemiological differences observed reflect a true ethnic difference in the phenotype of PCOS and whether there is an Asian phenotype for PCOS.