Defining Constant Versus Variable Phenotypic Features of Women with Polycystic Ovary Syndrome Using Different Ethnic Groups and Populations

Context: The phenotype of women with polycystic ovary syndrome (PCOS) is variable, depending on the ethnic background. Objective: The phenotypes of women with PCOS in Iceland and Boston were compared. Design: The study was observational with a parallel design. Setting: Subjects were studied in an outpatient setting. Patients: Women, aged 18–45 yr, with PCOS defined by hyperandrogenism and fewer than nine menses per year, were examined in Iceland (n = 105) and Boston (n = 262). Intervention: PCOS subjects underwent a physical exam, fasting blood samples for androgens, gonadotropins, metabolic parameters, and a transvaginal ultrasound. Main Outcome Measures: The phenotype of women with PCOS was compared between Caucasian women in Iceland and Boston and among Caucasian, African-American, Hispanic, and Asian women in Boston. Results: Androstenedione (4.0 ± 1.3 vs. 3.5 ± 1.2 ng/ml; P < 0.01) was higher and testosterone (54.0 ± 25.7 vs. 66.2 ± 35.6 ng/dl; P < 0.01), LH (23.1 ± 15.8 vs. 27.6 ± 16.2 IU/liter; P < 0.05), and Ferriman Gallwey score were lower (7.1 ± 6.0 vs. 15.4 ± 8.5; P < 0.001) in Caucasian Icelandic compared with Boston women with PCOS. There were no differences in fasting blood glucose, insulin, or homeostasis model assessment in body mass index-matched Caucasian subjects from Iceland or Boston or in different ethnic groups in Boston. Polycystic ovary morphology was demonstrated in 93–100% of women with PCOS in all ethnic groups. Conclusions: The data demonstrate differences in the reproductive features of PCOS without differences in glucose and insulin in body mass index-matched populations. These studies also suggest that measuring androstenedione is important for the documentation of hyperandrogenism in Icelandic women. Finally, polycystic ovary morphology by ultrasound is an almost universal finding in women with PCOS as defined by hyperandrogenism and irregular menses.