Alterations of oestradiol, testosterone, gonadotrophins and SHBG by type 2 diabetes in postmenopausal women

Abstract

AbstractSex hormones influence cardiovascular risk and bone mineral density. Total oestradiol is increased in postmenopausal women with type 2 diabetes, whereas its impact on androgens, sex hormone binding globulin (SHBG) and gonadotrophins in postmenopausal women is not so clearly understood. This study aims to clarify the impact of type 2 diabetes on sex hormone levels in Caucasian postmenopausal women.Type 2 diabetic (n=42) and non‐diabetic (n=45) postmenopausal women were recruited. Venous blood samples were drawn and assayed for total oestradiol, total testosterone, luteinising hormone (LH), follicle stimulating hormone (FSH) and SHBG. Ratio of total testosterone to SHBG was used as an index of free testosterone (FT).Total oestradiol and FT were significantly higher in diabetic subjects compared to controls— oestradiol median: 59.5(25th,75th centiles: 41.5,74.5) vs 42.5(37.0,59.8)pmol/L, p=0.009 Mann‐Whitney test; and FT: 0.038(0.021,0.070) vs 0.022(0.012,0.036), p=0.003. SHBG, FSH and LH were lower in diabetic subjects compared to controls— SHBG: 32(23.3,47.3) vs 55(37,70)nmol/L, p<0.001; FSH: 54.8(42.2,68.7) vs 71.8(55.9,98.9)iu/L, p=0.001; and LH: 27.9(20.6,39.7) vs 39.2(30.9,48.1)iu/L, p=0.011— but total testosterone was not different. The differences in oestradiol, SHBG and FSH remained when subjects were matched for BMI and age (n=29).Preliminary sub‐group analysis suggests that these differences may be influenced by form of diabetic therapy and glycaemic control. Type 2 diabetes is associated with altered levels of total oestradiol, FT, SHBG, FSH, LH, in postmenopausal women. However, further research is required to determine the impact of diabetic therapy and glycaemic control, and also the clinical relevance of these alterations. Copyright © 2007 John Wiley & Sons.