Objectives: The effects of hormone replacement therapy on cardiovascular risk factors in postmenopausal women with non-insulin dependent diabetes mellitus (type II diabetes) is uncertain.
Methods: The effects of estrogen replacement therapy (ERT, conjugated equine estrogen0.625mg orally daily), combined estrogen and continuous progestogen therapy (HRT, 0.625 mg of conjugated equine estrogens plus medroxyprogesterone acetate 5 mg daily) or placebo was compared in 20 postmenopausal type II diabetic women and 20 normal postmenopausal women in a double blind, randomised, crossover study. Patients receiving insulin were excluded from the study and all lipid modifying drugs were ceased at least 4 weeks prior to randomisation. Other medication including oral hypoglycaemics was kept constant for the duration of the study.
Results: Women with type II diabetes were a similar age (58.7+/-1.3 years) to the non-diabetic women (59.6+/-1.6 years) but they had a significantly greater body mass index, a higher incidence of treated hypertension, higher fasting plasma glucose levels, higher triglycerides and lower HDL cholesterol levels than non-diabetic women. ERT reduced total cholesterol and LDL cholesterol by a similar extent (8.9-12.3%) in normal and type II diabetic women and increased HDL cholesterol to a similar extent in both groups (11.0 and 8.9% respectively). ERT did not significantly alter fasting triglyceride levels in either group. The addition of medroxyprogesterone acetate 5 mg daily abolished the increase in HDL cholesterol associated with ERT in both groups but did not significantly affect any of the other lipid measurements. ERT and HRT did not significantly alter fasting insulin levels nor alter fasting glucose levels in either non-diabetic women or women with type II diabetes.
Conclusions: ERT and HRT have similar effects on lipids in women with type II diabetes and non-diabetic women after 1 month of therapy.