Objectives: Significant differences in the prevalence of menopausal symptoms and in lipid profiles have previously been reported for nine ethnic groups of postmenopausal Asian women participating in the Pan-Asia Menopause (PAM) study. Based on these findings, we tested the hypothesis that reproductive hormone profiles differ among the nine ethnic groups under investigation in the PAM study.
Methods: Baseline serum samples from postmenopausal women (n=1020) representing nine ethnic groups were analyzed at a central laboratory by electro-chemiluminescence immunoassay methods. Hormone concentrations were measured for estradiol (E2), follicle stimulating hormone (FSH) and luteinizing hormone (LH).
Results: The hormone levels for the overall study population (mean+/-SD) were: E2=74.1+/-125.1 pmol/l (n=1015); FSH=81.2+/-31.4 IU/l (n=1013); LH=36.8+/-15.6 IU/l (n=1015). Estradiol levels ranged from 50.0 pmol/l in Chinese women to 106.8 pmol/l in Vietnamese women; FSH ranged from 68.2 IU/l in Korean women to 90.8 IU/l in Malay women; and LH ranged from 30.7 IU/l in Korean women to 44.1 IU/l in Malay women. There was an inverse correlation between log E2 and FSH levels and a positive correlation between FSH and LH levels. The concentrations of E2, FSH and LH were significantly associated with ethnicity after adjustment for age and body mass index. Additionally, the concentrations of all three hormones were significantly associated with body mass index, whereas E2 and LH levels were associated with age, but FSH levels were not.
Conclusion: The levels of FSH, LH and particularly of E2 differ substantially among ethnic groups of postmenopausal Asian women. The clinical significance, if any, of these differences remains to be investigated. The inverse correlation of E2 and FSH levels suggests that E2 at the postmenopausal state still affects pituitary FSH output.