Does the type of hormone replacement therapy affect lipoprotein (a), homocysteine, and C-reactive protein levels in postmenopausal women?

Background: The results of studies evaluating the effect of hormone replacement therapy (HRT) on the cardiovascular risk raise many controversies. This may be related to both the type of treatment used and the disregard of additional risk factors. Objective: The objective of the study was to evaluate the effect of natural estrogens taken transdermally and synthetic estrogens taken orally on the concentrations of lipoprotein (a) [Lp(a)], homocysteine, and C-reactive protein (CRP) in healthy women in the early postmenopausal period. Material: The study was conducted on 61 healthy women with average age of 52.3 +/- 4.1 years, in the postmenopausal period, who were randomly assigned to 3 groups depending on the type and route of administration of the products. Group I (n = 24) was administered transdermal estrogens (micronized 17 beta-estradiol; Systen, Janssen-Cilag, Switzerland) and progesterone in the second phase of the cycle. Group H (n = 21) was administered oral hormones (Cyclo-Menorette). Group III (n = 16), serving as a control, included women taking placebo in the form of patches. In each group, therapeutic cycles took 22 days and were followed by a treatment-free interval of 7 to 10 days for a 3-month period. Results: After 3 months of treatment, Lp(a) and homocysteine levels were not significantly different from the baseline, irrespective of the route of administration of estrogens or placebo. Both forms of HRT used indicate significant difference in changes of CRP concentration during 3 months of administration (analysis of variance P = .0356). CRP concentration values increased in the group of women using oral HRT from 1.22 to 2.68 mg/L. In the group of women using oral therapy, significantly more cases (61%) of increase in CRP concentration compared with 39% in the transdermal HRT group (chi(2) P = .015) were observed. Conclusions: On the basis of our observations, it appears that in women in the early postmenopausal stage with normal initial concentrations of Lp(a) and homocystein, the form of therapy used has no influence on values of these parameters. The 2 forms of HRT therapy differ in effect, which is expressed as a change in CRP concentration. A tendency to increase CRP values when using oral HRT is observed, while such an effect is not observed in case of transdermal therapy after 3 months. (c) 2004 Elsevier Inc. All rights reserved.