Relationship between sex hormone-binding globulin levels and features of the metabolic syndrome.

Previous studies have demonstrated that reduced plasma levels of sex hormone-binding globulin (SHBG) are related to alterations in several features of the metabolic syndrome in both men and women. We investigated whether SHBG level was a global predictor of the metabolic syndrome in a sample of 203 men, 173 premenopausal, and 46 postmenopausal women for whom we also obtained a detailed assessment of the metabolic profile, including body composition (hydrostatic weighing), abdominal adipose tissue areas (computed tomography), plasma lipid-lipoprotein levels, and glucose homeostasis (oral glucose challenge). Low SHBG levels were associated with increased total and abdominal adiposity in men as well as in pre- and postmenopausal women. Low SHBG levels were also associated with an altered metabolic profile, especially in premenopausal women. Subjects were subdivided according to the presence of 0, 1 to 2, or 3 or more features of the metabolic syndrome. Twenty-five percent of men were characterized by 3 features or more, whereas most premenopausal women (61.3%) had a healthy metabolic profile (0 features) and 6.9% were characterized by 3 or more features. Most postmenopausal women (54.3%) were characterized by 1 to 2 components of the metabolic syndrome, and 13.0% were characterized by 3 or more components. The proportion of subjects characterized by the metabolic syndrome (3 components or more) was lower in subjects with SHBG values in the upper tertile compared with the lower tertile in both men and premenopausal women (17.7% v 28.4% and 1.7% v 14.0%, respectively). Logistic regression analyses indicated that an SHBG level in the upper tertile was associated with a significant reduction in the probability of being characterized by the metabolic syndrome (odds ratios of 0.35, P =.02 for men and.11, P =.05 for premenopausal women, with the lower tertile as a reference). The logistic regression was not significant in postmenopausal women. These results suggest that plasma SHBG level may represent a significant predictor of the metabolic syndrome in men and premenopausal women.