Objective: To assess serum lipid and lipoprotein concentrations and oral glucose tolerance in postmenopausal women treated with 17 beta-oestradiol (2 mg/day) and cyclical dydrogesterone (10 mg/day for 14 days per 28 day cycle).
Design: A 24 month prospective study of 29 women acting as their own controls. On-treatment samples were taken during the combined (oestrogen-progestogen) phase of therapy.
Setting: Metabolic research unit in London.
Population: Postmenopausal women with no previous exposure to hormone replacement therapy attending a menopause clinic in a London hospital.
Methods: Fasting serum sampling and oral glucose tolerance testing.
Main outcome measures: Serum lipids and lipoprotein concentrations and plasma glucose, insulin and C-peptide responses to an oral glucose load.
Results: Restricting the analysis to the 17 women who completed the study, no effect was seen on serum triglyceride concentrations. There was a mean fall of 5.9% (95% CI 1.2 to -13.0) in concentrations of serum total cholesterol, reflecting the balance of a 10.7% fall (95% CI 4.3 to -25.8) in low density lipoprotein cholesterol concentrations and a 16.3% increase (95% CI 7.3 to -25.3) in those of high density lipoproteins. Fasting glucose concentrations and glucose tolerance test responses were unchanged. Fasting insulin concentrations fell substantially (-41.6%, 95% CI -23.4 to -59.8) with falls also being seen in insulin responses to glucose. Fasting C-peptide concentrations increased by 36.2% (95% CI 9.17 to 63.3), with no consistent effect on C-peptide responses to glucose.
Conclusions: Dydrogesterone did not appear to oppose the potentially beneficial effects of oestradiol on insulin or either low or high density lipoproteins, making the combination with 17 beta-oestradiol a potentially useful option for postmenopausal women particularly those at risk of cardiovascular disease or diabetes mellitus.