Racial and ethnic differences in the polycystic ovary syndrome metabolic phenotype

Background: Women with polycystic ovarian syndrome have a high prevalence of metabolic syndrome and type 2 diabetes mellitus. Blacks and Hispanics have a high morbidity and mortality due to cardiovascular disease and diabetes mellitus in the general population. Since metabolic syndrome is a risk factor for development of type 2 diabetes and cardiovascular disease, understanding any racial and ethnic differences in metabolic syndrome among women with polycystic ovarian syndrome is important for prevention strategies. However, data regarding racial/ethnic differences in metabolic phenotype among women with polycystic ovary syndrome are inconsistent.

Objective: We sought to determine if there are racial/ethnic differences in insulin resistance, metabolic syndrome, and hyperandrogenemia in women with polycystic ovarian syndrome.

Study design: We conducted secondary data analysis of a prospective multicenter, double-blind controlled clinical trial, the Pregnancy in Polycystic Ovary Syndrome II study, conducted in 11 academic health centers. Data on 702 women with polycystic ovarian syndrome aged 18-40 years who met modified Rotterdam criteria for the syndrome and wished to conceive were included in the study. Women were grouped into racial/ethnic categories: non-Hispanic whites, non-Hispanic blacks, and Hispanic. The main outcomes were the prevalence of insulin resistance, metabolic syndrome, and hyperandrogenemia in the different racial/ethnic groups.

Results: Body mass index (35.1 ± 9.8 vs 35.7 ± 7.9 vs 36.4 ± 7.9 kg/m²) and waist circumference (106.5 ± 21.6 vs 104.9 ± 16.4 vs 108.7 ± 7.3 cm) did not differ significantly between non-Hispanic white, non-Hispanic black, and Hispanic women. Hispanic women with polycystic ovarian syndrome had a significantly higher prevalence of hirsutism (93.8% vs 86.8%), abnormal free androgen index (75.8% vs 56.5%), abnormal homeostasis model assessment (52.3% vs 38.4%), and hyperglycemia (14.8% vs 6.5%), as well as lower sex hormone binding globulin compared to non-Hispanic whites. Non-Hispanic black women had a significantly lower prevalence of metabolic syndrome (24.5% vs 42.2%) compared with Hispanic women, and lower serum triglyceride levels compared to both Hispanics and non-Hispanic whites (85.7 ± 37.3 vs 130.2 ± 57.0 vs 120.1 ± 60.5 mg/dL, P < .01), with a markedly lower prevalence of hypertriglyceridemia (5.1% vs 28.3% vs 30.5%, P < .01) compared to the other 2 groups.

Conclusion: Hispanic women with polycystic ovarian syndrome have the most severe phenotype, both in terms of hyperandrogenism and metabolic criteria. Non-Hispanic black women have an overall milder polycystic ovarian syndrome phenotype than Hispanics and in some respects, than non-Hispanic white women.