Racial and ethnic differences in the metabolic response of polycystic ovary syndrome

Context Polycystic ovary syndrome (PCOS) is a highly prevalent disorder associated with insulin resistance (IR) and compensatory hyperinsulinemia. Although variations in cardiometabolic risks across race and ethnicities have been reported in the general population, racial/ethnic disparities in the metabolic dysfunction of PCOS remain relatively unstudied. Objectives To determine whether markers of metabolic function differ in nondiabetic Asian American (AS), African American (AA), Hispanic White (HW), compared to non-Hispanic White (NHW) women with PCOS. Design and Setting Prospective cross-sectional study in a tertiary institution. Participants and Interventions A total of 259 nondiabetic women with PCOS (by NIH 1990 criteria) who completed a 2-hour 75-g oral glucose tolerance test measuring plasma glucose and insulin levels. Basal IR and insulin secretion, assessed by the homeostasis model assessment (HOMA-IR and HOMA-beta%, respectively), and two-hour hyperglycaemia and hyperinsulinemia after an oral glucose load, were compared in 21 AS, 24 AA, 53 HW and 161 NHW consecutive nondiabetic adult PCOS women. Results After adjusting for age and body mass index, HW and AA PCOS women demonstrated higher fasting and post-glucose challenge insulin levels, and higher HOMA-IR and HOMA-beta%, than NHW women, although glucose levels were similar. In contrast, AS PCOS women had or tended to have lower HOMA-beta% than any other racial/ethnic groups, lower HOMA-IR, and fasting and post-challenge insulin levels than AA or HW, and also had higher (albeit still normal) mean post-challenge glucose levels than NHW women with PCOS despite similar HOMA-IR, and fasting insulin and post-challenge insulin levels. Waist-hip ratio was similar across the four groups. Conclusion Both HW and AA women with PCOS have increased basal state IR and higher beta-cell response, and post-challenge hyperinsulinemia compared to NHW and AS subjects. The trend towards a lesser insulin response among Asian women requires further investigation. These findings suggest that the screening and management of metabolic dysfunction in PCOS should consider patients' race/ethnicity.