The lipid and clinical effects of sequential transdermal estradiol and estradiol/norethisterone acetate in 674 women

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 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.

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.

CONCLUSION

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.

LycoRed as an alternative to hormone replacement therapy in lowering serum lipids and oxidative stress markers: A randomized controlled clinical trial

AIM

Menopause is a pro-atherogenic state with a sharp rise in the incidence of coronary artery disease. This pilot study was designed as an equivalence randomized clinical trial to explore the potential of LycoRed (containing 2000 microg lycopene) as an alternative to hormone replacement therapy (HRT) for the prevention of coronary artery disease in postmenopausal women.

METHODS

Forty-one healthy postmenopausal women were randomly allocated to receive either continuous combined HRT (n = 21) or LycoRed (n = 20) for six months. Serum lipid profile, marker of lipid peroxidation (malondialdehyde), and the level of endogenous antioxidant (glutathione) were measured at the baseline, and 3 and 6 months after the intervention in both groups.

RESULTS

At 6 months, HRT resulted in a significant decrease in total cholesterol (TC) level by 23.5%, low-density lipoproteins (LDL) by 19.6%, and an increase in high-density lipoproteins (HDL) by 38.9%. The LycoRed group showed similar changes in TC (-24.2%), LDL (-14.9%) and HDL (+26.1%). Triglyceride levels showed a smaller though significant increase at 6 months, but not at 3 months, in both groups. There was no significant change in the very LDL (VLDL) level in either group. Malondialdehyde levels decreased significantly by 16.3% and 13.3%, whereas glutathione levels increased significantly by 5.9% and 12.5% in HRT and LycoRed groups, respectively.

CONCLUSION

Both HRT and LycoRed had a favorable effect on serum lipids and oxidative stress markers which were comparable. LycoRed can be used as an alternative to HRT to reduce the risk of atherosclerosis in postmenopausal women.

Effects of Transdermal Estrogen Replacement Therapy on Cardiovascular Risk Factors

The prevalence of hypertension and cardiovascular disease increases dramatically after menopause in women, implicating estrogen as having a protective role in the cardiovascular system. However, recent large clinical trials have failed to show cardiovascular benefit, and have even demonstrated possible harmful effects, of opposed and unopposed estrogen in postmenopausal women. While these findings have led to a revision of guidelines such that they discourage the use of estrogen for primary or secondary prevention of heart disease in postmenopausal women, many investigators have attributed the negative results in clinical trials to several flaws in study design, including the older age of study participants and the initiation of estrogen late after menopause.Because almost all clinical trials use oral estrogen as the primary form of hormone supplementation, another question that has arisen is the importance of the route of estrogen administration with regards to the cardiovascular outcomes. During oral estrogen administration, the concentration of estradiol in the liver sinusoids is four to five times higher than that in the systemic circulation. This supraphysiologic concentration of estrogen in the liver can modulate the expression of many hepatic-derived proteins, which are not observed in premenopausal women. In contrast, transdermal estrogen delivers the hormone directly into the systemic circulation and, thus, avoids the first-pass hepatic effect.Although oral estrogen exerts a more favorable influence than transdermal estrogen on traditional cardiovascular risk factors such as high- and low-density lipoprotein-cholesterol levels, recent studies have indicated that oral estrogen adversely influences many emerging risk factors in ways that are not seen with transdermal estrogen. Oral estrogen significantly increases levels of acute-phase proteins such as C-reactive protein and serum amyloid A; procoagulant factors such as prothrombin fragments 1+2; and several key enzymes involved in plaque disruption, while transdermal estrogen does not have these adverse effects.Whether the advantages of transdermal estrogen with regards to these risk factors will translate into improved clinical outcomes remains to be determined. Two ongoing clinical trials, KEEPS (Kronos Early Estrogen Prevention Study) and ELITE (Early versus Late Intervention Trial with Estradiol) are likely to provide invaluable information regarding the role of oral versus transdermal estrogen in younger postmenopausal women.