Glucose and Insulin Components of the Metabolic Syndrome Are Associated with Hyperandrogenism in Postmenopausal Women: The Atherosclerosis Risk in Communities Study
In 1990–1992, the authors investigated the association of total and free testosterone with the metabolic syndrome in postmenopausal US women not taking hormone replacement therapy (n = 362) in a prevalent case-control study of carotid atherosclerosis. Free testosterone was estimated by using the free androgen index (FAI) (total testosterone/sex hormone-binding globulin ratio). The metabolic syndrome was defined as the presence of three or more of the following criteria: waist circumference ≥35 inches (88.9 cm), triglycerides ≥150 mg/dl, high density lipoprotein cholesterol 130/80 mmHg, fasting insulin ≥100 pmol/liter, or impaired glucose homeostasis (fasting glucose ≥110 mg/dl or diagnosed diabetes mellitus). FAI, but not total testosterone, was strongly associated with the metabolic syndrome. Compared with women in the lowest FAI quartile, those in the highest quartile had a fivefold greater odds of having the metabolic syndrome (odds ratio = 5.38, 95% confidence interval: 2.70, 10.7) after adjustment for age, race, and carotid atherosclerosis status. In multivariate analyses, the three-component metabolic syndrome combinations that contained both hyperinsulinemia and hyperglycemia were most strongly associated with increased FAI (absolute increase = 0.41–0.54 compared with that for women who did not have these combinations; all p’s < 0.001). Higher FAI was associated with the hyperinsulinemia and hyperglycemia components of the metabolic syndrome. The role of androgens in glucose homeostasis in postmenopausal women requires further study.