The effect of continuous combined HRT on glucose homeostasis and plasma lipids: A placebo-controlled study in postmenopausal women with type 2 diabetes

BackgroundHyperandrogenicity in women is a risk factor for cardiovascular disease and noninsulin-dependent diabetes mellitus (NIDDM). Estradiol alone decreases hyperandrogenicity and have beneficial effects on glucose metabolism and plasma lipids in postmenopausal women with type 2 diabetes.ObjectivesTo analyse effects on glucose homeostasis and plasma lipids by 2 mg estradiol and 1 mg norethisterone acetate (NETA) given as a daily tablet during 6 months in postmenopausal women with type 2 diabetes.DesignRandomised, double-blind, placebo-controlled, cross-over design.Material and methodsThirty-one postmenopausal women with type 2 diabetes, glycosylated haemoglobin (HbA1c) of 6% or more and sex hormone-binding globulin (SHBG) values of 60 nmol/L or less were included. Anthropometric variables, blood pressure, sex steroid hormones, HbA1c, serum and lipoprotein lipids, plasminogen activator inhibitor 1 (PAI-1) and insulin-like growth factor 1 (IGF-1) were measured. An oral glucose tolerance test (OGTT) was performed and blood glucose, insulin and C-peptide were analysed. All measurements were taken at baseline and after each 6-month period.ResultsAn increase of SHBG and a decrease in free testosterone and PAI-1 levels was induced by the estradiol/NETA treatment compared with placebo. Lipoprotein(a) decreased but otherwise lipid metabolism was unaffected. No differences were recorded in glucose homeostasis between active treatment and placebo.ConclusionEstradiol/NETA therapy decreased hyperandrogenicity in postmenopausal women with type 2 diabetes. Lipoprotein(a) and PAI-1 which are independent risk factors for coronary heart disease decreased. No changes in glucose homeostasis were found.