ETHNICITY AND POLYCYSTIC-OVARY-SYNDROME ARE ASSOCIATED WITH INDEPENDENT AND ADDITIVE DECREASES IN INSULIN ACTION IN CARIBBEAN-HISPANIC WOMEN

This study was conducted to determine the impact of polycystic ovary s yndrome and ethnicity on insulin action. Thirteen Caribbean-Hispanic a nd 10 non-Hispanic white polycystic ovary syndrome women were compared with 5 Caribbean-Hispanic and 8 non-Hispanic white normal women match ed for age, weight, and body composition. All subjects underwent a 2-h 75 g oral glucose tolerance test and euglycemic glucose clamp study w ith a 40 mU . m-2 . min-1 insulin dose. Hepatic glucose production was determined basally and throughout the euglycemic clamp study. Polycys tic ovary syndrome was associated with significant increases in fastin g insulin levels (P < 0.05) and in 2-h postglucose-load glucose and in sulin levels (P < 0.001). Ethnicity was not associated with any change s in these parameters. Polycystic ovary syndrome but not ethnicity was also associated with hepatic insulin resistance, because significant (P < 0.05) residual hepatic glucose production occurred during the eug lycemic clamp in the polycystic ovary syndrome women. However, signifi cant independent effects existed for both polycystic ovary syndrome (P < 0.01) and ethnicity (P < 0.05) that resulted in decreased insulin-m ediated glucose disposal. Similarly, significant independent effects o f polycystic ovary syndrome (P < 0.005) and ethnicity (P < 0.05) occur red, resulting in increased steady-state insulin levels during the eug lycemic clamp. This appeared to be, in part, secondary to a decrease i n the metabolic clearance rate of insulin associated with ethnicity (P < 0.05). We conclude that polycystic ovary syndrome and ethnicity res ult in independent and additive decreases in insulin sensitivity in Ca ribbean-Hispanic women. Insulin resistance resulting in hyperinsulinem ia may account for the increased prevalence of both polycystic ovary s yndrome and of NIDDM in Caribbean-Hispanic women.