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

To compare the influence of different delivery forms of estrogen therapy (ET) on serum lipid levels.

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 microg/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.

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.

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.