Glycaemic control and plasma lipoproteins in menopausal women with Type 2 diabetes treated with oral and transdermal combined hormone replacement therapy.

AIMS: To compare the effect of a fixed combination of an oestrogen (17-beta oestradiol) with a cyclical progestagen (norethisterone) on glycaemic control, plasma lipoproteins and haemostatic factors in women with Type 2 diabetes. METHODS: Oral and transdermal hormone replacement therapy (HRT) were compared to no HRT treatment in 33 postmenopausal women with Type 2 diabetes, in a 12-week randomised prospective open parallel group study. RESULTS: In the 11 women who received 12 weeks of oral HRT, there was a significant fall in total cholesterol (5.9+/-1.0 (S.D.) to 4.7+/-1.0 mmol l(-1), P=0.005), low density lipoprotein cholesterol (3.44+/-0.89 to 2.77+/-0.92 mmol l(-1), P=0.005) and triglyceride values (median (range)), (2.46 (0.96-5.52) to 2.29 (1.00-3.87) mmol l(-1), P<0.05). Oral HRT improved glycated haemoglobin (HbA(1c)) (7.4+/-1.4 to 6.8+/-1.2%, P< or =0.005). Oral HRT additionally reduced the cell adhesion factor E-selectin (82+/-33 to 60+/-20 microg l(-1), P<0.01) and factor VII (143+/-25 to 109+/-24% pooled plasma activity, P<0.01). No improvement in any of these parameters, except E-selectin (65+/-19 to 58+/-18 microg l(-1), P<0.01), occurred in the nine women receiving transdermal HRT, and no improvement occurred in the 13 controls randomised to no treatment. CONCLUSION: In women with Type 2 diabetes, cyclical oestrogen and progestagen taken orally for 12 weeks significantly improved glycaemic control and lipoprotein concentrations. These metabolic benefits were not apparent when a similar HRT preparation was administered transdermally.