Androgens, insulin-like growth factor-I (IGF-I), and carrier proteins (SHBG, IGFBP-3) in postmenopause

Objective: To determinate the profile of androstenedione (A), total (T), and free testosterone (FT), dehydroepiandrosterone (DHEA), DHEA-sulphate (DHEAS), sex hormone-binding globulin (SHBG), insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 (IGFBP-3) in nonsmoking, postmenopausal women of normal weight and to search for correlations between hormones and carrier proteins and chronological age, number of years of postmenopause and age of onset of menopause. Design: A group of 149 postmenopausal women aged 49 to 74 years were divided into three groups based on the number of years of postmenopause: 2-4 years (group A), 9-12 years (group 13), and 19 years or more (group C). Seventy-two women aged 21 to 35 years were the controls. Hormones and carriers were assessed in all groups. Results: A, DHEA, DHEAS, and IGF-I were significantly lower than controls in all groups, whereas T, FT, SHBG, and IGBFP-3 were lower only in groups B and C. All hormones and carriers were negatively correlated with the number of years of postmenopause; DHEA and T also showed a positive correlation with the age of onset of menopause. Conclusions: Androgens, SHBG, and IGF-I/IGFBP-3 show a diversified decline in postmenopause that is involved in the physiological aging process. Thus, a modification, in excess or deficiency, could favor the development of central symptoms or pathologies.