Lipoprotein profiles in Mexican American and non-Hispanic white women with polycystic ovary syndrome.

OBJECTIVE: To compare lipid profiles between Mexican American and non-Hispanic white women with polycystic ovary syndrome (PCOS). DESIGN: Cross-sectional analysis using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. SETTING: University gynecology service. PATIENT(S): Self-identified Mexican Americans (n = 71) and non-Hispanic whites (n = 120) with PCOS defined by the 2003 European Society of Human Reproduction and Embryology and American Society of Reproductive Medicine consensus. INTERVENTION(S): Serum drawn from fasting state followed by oral glucose tolerance test. MAIN OUTCOME MEASURE(S): Age, body mass index (BMI), androgens, cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, fasting, and minimal model analyses of insulin sensitivity. RESULT(S): Mexican American women were more insulin resistant than non-Hispanic whites, but cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, and calculated non-HDL cholesterol levels were similar. BMI inversely correlated with HDL cholesterol and positively with triglycerides. Approximately half of both ethnic groups had at least one lipid level in the low (HDL) or high (cholesterol, triglycerides, and LDL cholesterol) range according to National Cholesterol Education Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults guidelines. CONCLUSION(S): Despite greater insulin resistance among Mexican Americans with PCOS, lipid levels were similar to those of age- and weight-matched non-Hispanic whites. Obesity adversely affected lipid levels-primarily HDL cholesterol and triglycerides-in both groups. The prevalence of dyslipidemia was approximately 50% in each ethnic group.

Hyperinsulinemia and circulating dehydroepiandrosterone sulfate in white and Mexican American women with polycystic ovary syndrome.

OBJECTIVE: To determine whether Mexican American women with polycystic ovary syndrome (PCOS), a population more insulin resistant than white women with PCOS, demonstrate differences in adrenal androgen production. DESIGN: Retrospective study. SETTING: University gynecology clinic and research laboratory. PATIENT(S): One hundred eleven white women and 50 Mexican American women with PCOS based on the 2003 Rotterdam Consensus Statement. INTERVENTION(S): Blood sampling, oral glucose tolerance testing, and ultrasonography. MAIN OUTCOME MEASURE(S): Serum total T, free T, DHEAS, and calculation of multiple insulin sensitivity indices after an oral glucose challenge. RESULT(S): Mexican American women with PCOS were significantly more insulin resistant than their white counterparts but had lower circulating levels of DHEAS, a reliable index of adrenal androgen production. Age and body mass index (BMI) were each inversely proportional to serum DHEAS, but no association was found between circulating insulin and serum DHEAS levels. Testosterone levels were similar between groups. CONCLUSION(S): The lower levels of DHEAS observed in the more insulin resistant Mexican American group with PCOS (compared to a similar group of white women living in the same locale) further corroborates the extent of phenotypic variability among specific PCOS populations. Hyperinsulinemia does not appear to significantly influence circulating adrenal androgen levels in PCOS.

Polycystic ovarian syndrome and insulin resistance in white and Mexican American women: a comparison of two distinct populations.

OBJECTIVES: We sought to determine what differences, if any, existed between white and Mexican American women with polycystic ovary syndrome (PCOS) and whether the same values for fasting insulin, fasting glucose/insulin ratio, and homeostasis model assessment (HOMA) might be applied when screening both ethnic groups for insulin resistance. STUDY DESIGN: Eighty-three consecutive women suspected to have PCOS but who demonstrated absence of other endocrine disorders comprised the study population. Nineteen healthy ovulatory women volunteered as controls. Fasting serum samples were obtained for determination of thyroid-stimulating hormone (TSH), prolactin, glucose, insulin, free and total testosterone, 17-hydroxyprogesterone, and dehydroepiandrosterone sulfate in the early proliferative phase. An oral glucose load was administered, and blood samples for glucose and insulin were drawn at 1, 2, and 3 hours. Those with impaired glucose tolerance or diabetes mellitus were excluded from our final study population. Four different groups were defined: (1) women with PCOS and insulin resistance, (2) women with PCOS without insulin resistance, (3) women with irregular cycles but without PCOS or another identifiable endocrinopathy, and (4) regular, cycling control subjects. Each group was subdivided by ethnicity (white or Mexican American). A total of 65 white and 37 Mexican American women were studied, including control subjects. RESULTS: Among all study participants, Mexican American women with PCOS had significantly higher mean values for body mass index, fasting insulin, and HOMA but lower mean fasting glucose/insulin levels than white women. When group 1 patients (PCOS with insulin resistance) were compared between ethnic groups, mean fasting insulin and HOMA levels were significantly lower and glucose/insulin ratios higher in white than in Mexican American women. A single cutoff value for insulin resistance in PCOS was insensitive when applied to both ethnic groups. A fasting insulin value >20 microU/mL, HOMA value > 3.8, and glucose/insulin value <7.2 were reasonable screening values in our population of white women, whereas a fasting insulin value >23 microU/mL, HOMA value >4.5, and glucose/insulin ratio <4.0 were feasible screening values in Mexican American women. CONCLUSIONS: We conclude that (1) Mexican American women with PCOS are more insulin resistant than white women, (2) the incidence of insulin resistance is higher in Mexican American women with PCOS than in white women, (3) a single "screening" value for PCOS-related insulin resistance screening cannot be applied to both white and Mexican American women, and (4) normative values for insulin resistance screening in the PCOS population should be individualized for different racial or ethnic populations.