Do different delivery systems of estrogen therapy influence serum lipids differently in surgically menopausal women?

Aim: To compare the influence of different delivery forms of estrogen therapy (ET) on serum lipid levels. Methods: For this prospective, randomized, controlled study, 132 surgically menopausal women were assigned to 12 months of therapy with oral conjugated estrogen 0.625 mg/day (n = 35), intranasal 300 mu g/day estradiol hemihydrate (n = 33), percutaneous gel 1.5 mg/day estradiol hemihydrate (n = 32) or no treatment (control group, n = 32). Total cholesterol (t-Chol), triglycerides, high-, low-, and very low-density lipoprotein (HDL-Chol, LDL-Chol, and VLDL-Chol, respectively) levels were determined at baseline, and cycles 6 and 12. Data were analyzed using repeated measures ANOVA. Results: All delivery forms significantly decreased t-Chol and LDL-Chol while increasing HDL-Chol after 6 and 12 cycles. The oral route significantly increased whereas other modalities significantly decreased serum triglycerides after cycle 6 and 12. VLDL-Chol levels were significantly increased using the oral route after cycle 12 while intranasal and percutaneous gel forms decreased the level after cycles 6 and 12. Conclusions: Oral, intranasal and transdermal gel delivery modes of ET have beneficial effects on serum lipids, as shown by decreased t-Chol and LDL-Chol, and increased HDL-Chol levels in surgically menopausal women. The oral form should be used with care in women with hypertriglyceridemia and with increased VLDL-Chol levels. However, the oral route seems to be more effective in decreasing LDL-Chol levels than the percutaneous gel form.