Effect of raloxifene, estrogen, and hormone replacement therapy on serum homocysteine levels in postmenopausal women

The Effects of Bazedoxifene on Bone, Glucose, and Lipid Metabolism in Postmenopausal Women With Type 2 Diabetes: An Exploratory Pilot Study

Background

Selective estrogen receptor modulators (SERMs) decrease homocysteine and cross-linking of pentosidine and reduce low-density lipoprotein cholesterol (LDL-C), and they are expected to improve bone quality and atherosclerosis. Therefore, the potential effects of bazedoxifene on bone (bone resorption, bone formation, and bone quality), as well as on glucose and lipid metabolism markers, were examined in Japanese postmenopausal women with type 2 diabetes mellitus (T2DM).

Methods

Eligible patients received 20 mg of bazedoxifene tablets once daily and were followed up for 12 weeks. Bone resorption markers including tartrate-resistant acid phosphatase 5b (TRACP-5b), bone formation markers and bone quality markers such as homocysteine and serum pentosidine, total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), and HbA1c were all measured.

Results

Twenty patients completed this study. All bone resorption markers decreased significantly 4 weeks after bazedoxifene treatment. In particular, TRACP-5b decreased significantly at 12 weeks (median percent change: -20.6%), and the minimum significant change (MSC) achievement rate of TRACP-5b was 65%. Bazedoxifene also decreased bone formation markers. However, bazedoxifene did not improve bone quality markers. LDL-C, HDL-C, and non-HDL-C were decreased, but TG was unchanged. Glucose metabolism was not changed after bazedoxifene treatment. In a subgroup analysis, the group of patients in whom the percent change in TRACP-5b exceeded the MSC had no change in pentosidine levels at 12 weeks. However, in the group of patients in whom the percent change in TRACP-5b did not exceed the MSC, pentosidine levels tended to increase.

Conclusions

Bazedoxifene may improve bone resorption markers and LDL-C without affecting glucose metabolism in Japanese postmenopausal women with T2DM.

The effect of postmenopausal hormone therapy with or without folic acid supplementation on serum homocysteine level

OBJECTIVE

To evaluate the effects of postmenopausal hormone therapy (HT) with or without the addition of folic acid (FA) on serum homocysteine levels in a randomized, placebo-controlled design. Additionally, a non-randomized control group with no treatment was included.

METHODS

Forty non-hysterectomized healthy postmenopausal women were randomly allocated to receive either oral continuous combined HT (0.625 mg conjugated equine estrogen with 2.5 mg medroxyprogesterone acetate daily) and oral folic acid (5 mg/day, n = 20) or HT and placebo (n = 20) for 3 months. A control group (n = 15) did not receive any study medication and was followed in the same manner. The fasting total serum homocysteine level was measured by fluorescence polarization immunoassay with a sensitivity of < 0.5 micromol/l. Serum levels of folate, estrogen and lipid profile were also followed.

RESULTS

The mean age of the postmenopausal women was 52 +/- 6 years. Baseline homocysteine level was the highest in the HT + FA group (9.96 +/- 2.82 micromol/l), compared to HT + placebo (9.64 +/- 1.89 micromol/l) and control groups (9.01 +/- 1.83 micromol/l) (ANCOVA, p = 0.022). Low baseline folate and vitamin B12 levels contributed significantly to the high level of baseline homocysteine in the HT + FA group. The addition of FA to HT led to a significant decrease in the serum homocysteine level from the baseline level of 9.96 +/- 2.82 micromol/l to the final level of 8.92 +/- 2.53 micromol/l (p = 0.023). On the other hand, HT alone (HT + placebo group) significantly increased the serum homocysteine level from 9.64 +/- 1.89 micromol/l to 10.22 +/- 1.77 micromol/l without a decline in serum folate level (p = 0.045). The serum homocysteine level in the control group did not change significantly (from 9.01 +/- 1.83 micromol/l to 9.58 +/- 2.05 micromol/l, p = 0.29).

CONCLUSIONS

Three months of oral continuous combined HT increased the fasting total serum homocysteine level without affecting the serum folate level. Lowering the homocysteine level in postmenopausal woman on HT is achievable by folic acid supplementation.

No effect of menstrual cycle on LDL oxidizability and particle size

OBJECTIVES

Premenopausal women have a lower incidence of cardiovascular disease than men, but this female advantage disappears after menopause, suggesting that female sex hormones exert some cardioprotective effects. One of the mechanisms proposed to explain this cardioprotection is the antioxidant properties of estrogens. The aim of this work was to assess whether fluctuations in ovarian hormones, particularly 17beta-estradiol (E(2)), during the menstrual cycle were associated with changes in the low-density lipoprotein (LDL) particle size, fatty acyl composition, alpha-tocopherol content and in vitro oxidizability.

METHODS

Twenty-eight healthy premenopausal women (mean age: 32.2 years) participated in the study. Blood was drawn on days 3 (menstrual phase), 14 (follicular phase) and 22 (luteal phase) of the menstrual cycle for plasma determinations and LDL isolation. Plasma E(2), progesterone, follicle-stimulating hormone and luteinizing hormone were determined by immunoassay. LDL oxidation by Cu(2+)- and 2,2'-azobis (2-amidinopropane) was measured by the formation of conjugated dienes, LDL particle size by quasi-elastic light scattering, fatty acyl composition by gas chromatography, alpha-tocopherol by reversed phase HPLC. A within-subjects analysis of variance was performed to determine significant differences of the variables over the course of a subject's menstrual cycle.

RESULTS

The LDL oxidizability indices (lag time before the onset of propagation and the maximal oxidation rate) did not change during the menstrual cycle. The LDL particle size (24.8+/-1.7 nm diameter), alpha-tocopherol (11.7+/-3.7 nmol/mg LDL protein) and fatty acyl composition also remained constant.

CONCLUSIONS

The LDL physicochemical properties and oxidizability are not affected by menstrual cycle phase.

The Cardiovascular Effects of Selective Estrogen Receptor Modulators

Coronary artery disease (CAD) is the main contributor of mortality among postmenopausal women. Menopause-associated estrogen deficiency has both metabolic and vascular consequences that increase the risk for CAD. Hormone therapy (HT) has been reported to have a beneficial effect on metabolic and vascular factors influencing the incidence of CAD. Although observational studies have reported that HT reduces significantly the risk for CAD, randomized clinical trials (WHI, HERS, ERA) have questioned the efficacy of HT in primary and secondary CAD prevention despite confirming the lipid-lowering effect of HT. In the aftermath of the WHI, increased interest has been given to the action of selective estrogen receptor modulators (SERMs) and their effect on the cardiovascular system. The chemical structure of SERMs, either triphenylethilyn (tamoxifen) or benzothiophene (raloxifene) derivatives, differs from that of estrogens. SERMs are nonsteroidal molecules that bind, with high affinity, to the ER. SERMs induce conformational changes to the ligand-binding domain of the ER that modulate the ability of the ER to interact with coregulator proteins. The relative balance of coregulators within a cell determines the transcriptional activity of the receptor-ligand complex. SERMs therefore may express an estrogen-agonist or estrogen-antagonist effect depending on the tissue targeted. SERMs express variable effects on the metabolic and vascular factors influencing the incidence of CAD. SERMs have been reported to modulate favorably the lipid-lipoprotein profile. Toremifene expresses the most beneficial effect followed by tamoxifene and raloxifene, while ospexifene and HMR-3339 have the least effect and may even increase triglycerides. Raloxifene and tamoxifene decrease serum homocysteine levels and C-reactive proteins (CRP), which are both markers of CAD risk. Raloxifene has been reported to increase the nitric oxide (NO)-endothelin (ET)-1 ratio and, thus, contribute to proper endothelial function and vasodilation. Toremifene has no effect on the NO-ET-1 ratio. Finally, raloxifene decreases the vascular cell adhesion molecules and the inflammatory cytokines TNF-alpha and IL-6. Of the SERMs, raloxifene has had the most extensive evaluation regarding the effect on the vascular wall of endothelium. Although not confirmed by large clinical trials, raloxifene has been reported to have an effect on the cohesion of the intercellular junction (VE-cadherin) and the synthesis-degradation of extracellular matrix (MMP-2). The Multiple Outcomes Raloxifene Evaluation (MORE) study has reported that raloxifene may have a cardioprotective effect when administered to postmenopausal women at high risk for CAD disease.

Circulating chemoattractants RANTES, negatively related to endogenous androgens, and MCP-1 are differentially suppressed by hormone therapy and raloxifene

BACKGROUND

The cardinal role of chronic inflammation in the development of atherosclerosis is increasingly being recognized. Estrogens may prevent the evolution of atherosclerosis by suppressing immune response. Furthermore, the conflicting reports on the cardiovascular effects of hormone therapy between observational and clinical trials have triggered interest on the effect of alternative therapies on the cardiovascular system.

OBJECTIVE

The aim of this study was to assess the effect of estrogen, estrogen-progestin, tibolone and raloxifene therapy on circulating markers of chemotaxis in healthy postmenopausal women.

METHODS

Eighty-eight postmenopausal women aged 44-62 years were randomly allocated to daily: (1) conjugated equine estrogens 0.625 mg (CEE), (2) 17beta-estradiol 1mg plus norethisterone acetate 0.5mg (E(2)/NETA), (3) tibolone 2.5mg, (4) raloxifene HCl 60 mg or (5) no treatment. Serum monocyte chemoattractant protein-1 (MCP-1) and regulated upon activation, normal T-cell expressed and secreted (RANTES) were measured at baseline and at 3 months.

RESULTS

Endogenous testosterone and free androgen index (FAI) correlated negatively, while SHBG correlated positively with serum RANTES (testosterone: r=-0.27, p=0.033; FAI: r=-0.43, p=0.004: SHBG: r=0.34, p=0.026). Serum MCP-1 decreased significantly in the CEE group (baseline 125.3+/-51 pg/ml, 3 months 84.5+/-36.1 pg/ml, p=0.043), while no difference was detected between baseline and post-treatment levels in the other groups. Furthermore, a significant decrease in serum RANTES was observed at the end of 3 months only in the E2/NETA and the raloxifene group (E2/NETA baseline 8690.6+/-3880.0 pg/ml, 3 months 6894.0+/-1720.0 pg/ml, p=0.007; raloxifene baseline 9042.4+/-3765.6 pg/ml, 3 months 6718.1+/-2366.2 pg/ml, p=0.011).

CONCLUSION

Endogenous androgens may suppress chemotactic response. Postmenopausal hormone therapy and raloxifene may inhibit the expression of chemoattractant molecules and thus attenuate inflammation. The relevance of these findings in terms of clinically established caridoprotection remains to be clarified.

A 5-year study on the effect of hormone therapy, tibolone and raloxifene on vaginal bleeding and endometrial thickness

OBJECTIVES

To study the effect of standard and low-dose estrogen-progestin therapy (EPT), tibolone and raloxifene on the incidence of vaginal spotting/bleeding and endometrial thickness over a 5-year period.

METHODS

Seven hundred eighty-six postmenopausal women were studied in an open prospective design. Vaginal spotting/bleeding and endometrial thickness as assessed by transvaginal ultrasonography was compared between six categories of women over a 5-year period: three categories in women on continuous combined estrogen-progestin therapy, one category under tibolone, one category under raloxifene and one under no treatment. More specifically, women received tibolone 2.5 mg (N = 204), raloxifene HCl 60 mg (N = 137), conjugated equine estrogens 0.625 mg/medroxyprogesterone acetate 5mg (N = 122), 17beta-estradiol 2mg/norethisterone acetate 1mg (N = 58), 17beta-estradiol 1mg/norethisterone acetate 0.5mg (N = 76) or no therapy (controls, N = 189). Women with suspected endometrial pathology were referred for hysteroscopy.

RESULTS

Bleeding/spotting incidence was highest among standard dose EPT users (conjugated equine estrogens 0.625 mg/medroxyprogesterone acetate 5mg: 40.1%, 17beta-estradiol 2mg/norethisterone acetate 1mg: 44.8%, p < 0.001 compared to controls). Low-dose EPT associated with lower incidence of spotting/bleeding (34.1%). The incidence under tibolone and raloxifene was 22.5% and 2.9%, respectively, while 3.2% of women not receiving therapy reported vaginal spotting/bleeding. Mean endometrial thickness was not significantly affected in any of the groups studied. The drop-out rate due to spotting/bleeding was higher in the two higher dose EPT regimens. After logistic regression analysis, age at baseline was the only significant predictor of subsequent spotting/bleeding (b = -0.25, S.E. = 0.09, p = 0.006), while menopausal age and pre-treatment serum FSH had marginal significance.

CONCLUSIONS

EPT, tibolone and raloxifene do not appear to associate with significant changes in endometrial thickness in the majority of cases. The low-dose EPT regimen associated with a decreased incidence of unscheduled spotting/bleeding compared to the standard dose regimens. Tibolone expressed a favorable endometrial profile, as seen in its effect on unscheduled spotting/bleeding and mean endometrial thickness. Raloxifene associated with the lowest incidence in S/B and the lowest drop-out rate.s.

Effects of estrogen, raloxifene, and hormone replacement therapy on serum C-reactive protein and homocysteine levels

OBJECTIVES

To investigate the effects of conjugated equine estrogen (CEE), CEE plus medroxyprogesterone acetate (MPA), CEE plus Nomegestrol acetate (NA), and raloxifene on serum high sensitivity C-reactive protein (hs-CRP) and homocysteine (Hcy) levels in healthy postmenopausal women.

MATERIALS

One hundred seven healthy postmenopausal women were recruited in a prospective, randomized, and placebo-controlled 6 months study. Of these, 18 were hysterectomized and received daily oral 0.625 mg CEE. Eighty nine non-hysterectomized women were randomly allocated to one of four groups: a group (22 patients) treated with CEE, 0.625 mg/daily plus MPA 2.5 mg/daily; a group (22 patients) treated with CEE, 0.625 mg/daily plus NA 5 mg/daily; a group (23 patients) treated with raloxifene hydrochloride, 60 mg once daily; and a placebo group (22 patients). Hcy and hs-CRP were measured at baseline and at 3 and 6 months.

RESULTS

CEE (20%, P=0.03) and CEE+MPA (59%, P=0.006) increased serum hs-CRP levels significantly, whereas CEE+NA decreased serum hs-CRP by 25% (P=0.01). Raloxifene had no significant effect on serum hs-CRP levels during and after the treatment. In all active treatment groups serum Hcy levels decreased significantly compared to baseline and placebo.

CONCLUSIONS

Conjugated equine estrogen, hormone replacement therapies, and raloxifene lower serum Hcy levels to a comparable extent in postmenopausal women. Hs-CRP, as a cardiovascular risk factor, is not influenced by raloxifene, whereas CEE and CEE plus MPA significantly increase hs-CRP levels. Treatment with CEE plus NA reduces serum hs-CRP levels.

Effect of oral conjugated equine estrogen combined with medroxyprogesterone acetate on plasma homocysteine levels in postmenopausal women

Conjugated equine estrogen alone or combined with medroxyprogesterone acetate lowered homocysteine levels in postmenopausal women. Regardless of the dosage of progestin used, there was no impact on homocysteine metabolism after 3 years of therapy.

Homocysteine and vitamin B12 status relate to bone turnover markers, broadband ultrasound attenuation, and fractures in healthy elderly people

Hyperhomocysteinemia may contribute to the development of osteoporosis. The relationship of Hcy and vitamin B12 with bone turnover markers, BUA, and fracture incidence was studied in 1267 subjects of the Longitudinal Aging Study Amsterdam. High Hcy and low vitamin B12 concentrations were significantly associated with low BUA, high markers of bone turnover, and increased fracture risk.

INTRODUCTION

Hyperhomocysteinemia may contribute to the development of osteoporosis. Vitamin B12 is closely correlated to homocysteine (Hcy). The main objective of our study was to examine the association of Hcy and vitamin B12 status and the combined effect of these two with broadband ultrasound attenuation (BUA), bone turnover markers, and fracture.

MATERIALS AND METHODS

Subjects were 615 men and 652 women with a mean age of 76 +/- 6.6 (SD) years of the Longitudinal Aging Study Amsterdam (LASA). At baseline (1995/1996), blood samples were taken after an overnight fast for dairy products. Plasma Hcy was measured with IMx, serum vitamin B12 with competitive immunoassay (IA) luminescence, serum osteocalcin (OC) with immunoradiometric assay (IRMA), and urinary excretion of deoxypyridinoline (DPD) with competitive IA and corrected for creatinine (Cr) concentration. CVs were 4%, 5%, 8%, and 5%, respectively. BUA was assessed in the heel bone twice in both the right and left calcaneus. Mean BUA value was calculated from these four measurements. CV was 3.4%. After baseline measurements in 1995, a 3-year prospective follow-up of fractures was carried out until 1998/1999. Subjects were grouped by using two different approaches on the basis of their vitamin B12 concentration, normal versus low (<200 pM) or lowest quartile (Q1) versus normal quartiles (Q2-Q4), and Hcy concentration, normal versus high (>15 microM) or highest quartile (Q4) versus normal quartiles (Q1-Q3). Analysis of covariance was performed to calculate mean values of BUA, OC, and DPD/Cr(urine) based on the specified categories of Hcy and vitamin B12 and adjusted for several confounders (potential confounders were age, sex, body weight, body height, current smoking [yes/no], mobility, cognition). The relative risk (RR) of any fracture was assessed with Cox regression analysis. Quartiles were used when Hcy and vitamin B12 were separately studied in their relationship with fracture incidence.

RESULTS

Fourteen percent of the men and 9% of the women had high Hcy (>15 microM) and low vitamin B12 (<200 pM) concentrations. Women with vitamin B12 levels <200 pM and Hcy concentrations >15 microM had lower BUA, higher DPD/Cr, and higher OC concentrations than their counterparts. In men, no differences were found between the different Hcy and vitamin B12 categories in adjusted means of BUA, OC, or DPD/Cr(urine). Twenty-eight men and 43 women sustained a fracture during the 3-year follow-up period. The adjusted RR for fractures (95% CI) for men with high Hcy and/or low vitamin B12 concentrations was 3.8 (1.2-11.6) compared with men with normal Hcy and vitamin B12 concentrations. Women with high Hcy and/or low vitamin B12 concentrations had an adjusted RR for fractures of 2.8 (1.3-5.7).

CONCLUSIONS

High Hcy and low vitamin B12 concentrations were significantly associated with low BUA, high markers of bone turnover, and increased fracture risk.

Effect of hormone therapy on the elastic properties of the arteries in healthy postmenopausal women

The aim of the study was to assess the effect of continuous hormone therapy (HT) for 1 yr on pulse wave analysis and central aortic pressure in healthy postmenopausal women. Sixty-five healthy postmenopausal women were randomly allocated to receive either conjugated equine estrogens 0.625 mg plus medroxyprogesterone acetate 5 mg (CEE/MPA, Premelle 5, Wyeth-Ayerst Lab, Philadelphia, PA, no.=32) or no therapy (no.=33). Treatment was continuous, and the study period lasted 12 months. Central aortic pressure, augmentation and augmentation index (AI) were determined non-invasively using applanation tonometry. All measurements were performed at baseline and at the end of the study by the same person. Ns differences were found between baseline values and values at the end of the study in either the control or the CEE/MPA group in central systolic aortic pressure (107.0 +/- 13.1 vs 107.6 +/- 11.3 mmHg, p=0.80, and 110.8 +/- 10.8 vs 112.3 +/- 11.4 mmHg, p=0.23, respectively), augmentation (12.6 +/- 4.2 vs 11.9 +/- 4.8 mmHg, p=0.45 and 11.7 +/- 3.7 vs 12.6 +/- 4.2 mmHg, p=0.34, respectively), and percentage of AI (36.8 +/- 9.3 vs 36.3 +/- 10.3, p=0.81 and 34.1 +/- 8.9 vs 34.9 +/- 9.8, p=0.72, respectively). The results of this preliminary report suggest that HT for 1 yr does not have any significant effect on central aortic pressure and wave reflection in healthy postmenopausal women.

The effect of hormone therapy on plasma homocysteine levels: a randomized clinical trial*

OBJECTIVE

An elevated plasma homocysteine level is a risk factor for cardiovascular diseases. Hormone therapy (HT) may reduce fasting plasma homocysteine levels. We studied 80 postmenopausal women to determine the effect of medroxyprogesterone acetate (MPA) combined with conjugated equine estrogens (CEE) on fasting plasma homocysteine levels.

DESIGN

In a randomized, double blind, prospective, placebo-controlled study, we randomly assigned 80 healthy postmenopausal women between CEE 0.625 mg/d combined with MPA 2.5 mg/d (n = 20), CEE 0.625 mg/d combined with MPA 5 mg/d (n = 20), unopposed CEE 0.625 mg/d (n = 20), and placebo (n = 20) all given for a duration of 6 months. Fasting plasma homocysteine levels were measured before and at the end of the treatment.

RESULTS

Before treatment, plasma homocysteine concentrations were similar in all groups. After 6 months of unopposed CEE, the mean fasting plasma homocysteine levels decreased by 19.02% when compared with baseline levels (P < 0.05). The mean fasting plasma homocysteine concentrations decreased by 17.63% and 19.56% from baseline in both the CEE plus MPA 2.5 mg/d and CEE plus MPA 5 mg/d groups, respectively (P < 0.05 for each group). In contrast, plasma homocysteine levels increased by 11.66% in the placebo group. The homocysteine lowering effect did not differ significantly among the three groups of women receiving unopposed CEE alone and CEE plus MPA at two different doses.

CONCLUSION

Six months of estrogen therapy (ET) and combined estrogen-progestogen therapy (EPT) significantly lower fasting plasma homocysteine levels in healthy postmenopausal women with equal efficacy.

Effect of hormone therapy and raloxifene on serum VE-cadherin in postmenopausal women

OBJECTIVE

To investigate the effect of continuous combined hormone therapy and raloxifene on serum VE-cadherin.

DESIGN

The study was double blinded, with a placebo run-in period of 28-50 days.

SETTING

University menopause clinic.

PATIENT(S)

Twenty-eight healthy postmenopausal women devoid of climacteric complaints.

INTERVENTION(S)

Subjects were randomized to 17beta-estradiol (2 mg) + norethisterone acetate (1 mg; E(2)-NETA) or raloxifene hCL (60 mg) for a period of 6 months.

MAIN OUTCOME MEASURE(S)

Serum VE-cadherin, which was estimated at baseline and at month 6.

RESULT(S)

Serum VE-cadherin decreased significantly in both E(2)-NETA and raloxifene groups (raloxifene baseline +/- SD: 1.17 +/- 0.44 ng/mL, 6 months: 0.82 +/- 0.29 ng/mL; E(2)-NETA baseline: 1.19 +/- 0.47 ng/mL, 6 months: 0.92 +/- 0.49 ng/mL). Percentage changes from baseline were -21.7 +/- 24.3 for E(2)-NETA and -26.0 +/- 20.6 for raloxifene.

CONCLUSION(S)

The effect of E(2)-NETA and raloxifene suggests that these drugs may preserve interendothelial junction integrity and control vascular permeability. Although this effect may influence the progress of the atheromatous lesion, its clinical impact on coronary artery disease (CAD) remains uncertain.

Effect of supraphysiologic doses of testosterone on fasting plasma total homocysteine concentrations in men with Klinefelter's syndrome

OBJECTIVE

To examine the effect of supraphysiologic doses of testosterone (T) on plasma total homocysteine (tHcy) concentrations in patients with Klinefelter's syndrome (KS).

DESIGN

Prospective clinical study.

SETTING

University hospital.

PATIENT(S)

Thirty-two newly diagnosed male patients with KS, and 20 healthy, volunteer controls matched by age and body mass index.

INTERVENTION(S)

Testosterone was administered IM every 2 weeks for 6 months. Initially, pretreatment fasting blood samples were collected after overnight fasting. Posttreatment blood samples were drawn 7 days after the last injection.

MAIN OUTCOME MEASURE(S)

Plasma total homocysteine.

RESULT(S)

The KS patients had lower tHcy levels than the controls. However, plasma fasting tHcy concentrations increased in a statistically significant manner after 6 months of treatment. As compared with the levels among controls, pretreatment levels of the serum creatinine, hemoglobin, and hematocrit were significantly lower, and increased in a statistically significant way following treatment. Posttreatment levels of total cholesterol were statistically significantly higher than the baseline. The pretreatment folate and cobalamin levels also were statistically significantly higher in patients when compared with controls, and decreased significantly after treatment. The linear regression analysis showed that only creatinine, cobalamin, and folate were independently associated with plasma tHcy levels in patients before and after treatment.

CONCLUSION(S)

The patients with KS showed lower tHcy concentrations than healthy, age-matched male controls. Testosterone treatment increased plasma tHcy levels.

The effect of hormone therapy and raloxifene on serum matrix metalloproteinase-2 and -9 in postmenopausal women

OBJECTIVE

The aim of the study was to investigate the effect of continuous-combined hormone therapy and raloxifene on the total and active forms of serum matrix metalloproteinase (MMP) -2 and -9.

DESIGN

The study was double-blinded, with a placebo run-in period of 28 to 50 days. Twenty-eight women received either 17beta-estradiol 2 mg + norethisterone acetate 1 mg (E2/NETA) or raloxifene HCL 60 mg for a period of 6 months. Total and active forms of MMP-2 and -9 were estimated at baseline and at month 6.

RESULTS

Total MMP-2 increased significantly in both E2/NETA and raloxifene groups (raloxifene baseline: 278.1 +/- 18.1 ng/mL; 6 months: 303.1 +/- 29.9 ng/mL, P = 0.008) (E2/NETA baseline: 281.9 +/- 27.5 ng/mL; 6 months: 298.8 +/- 12.7 ng/mL, P = 0.025). Similarly, both treatments increased the active MMP-2 fraction, although only the raloxifene-associated increase acquired significance (raloxifene baseline: 24.9 +/- 8.6 ng/mL; 6 months: 31.6 +/- 15.3 ng/mL, P = 0.045) (E2/NETA baseline: 21.7 +/- 5.7 ng/mL; 6 months: 27.4 +/- 5.8 ng/mL, P = 0.128). Total as well as active fractions of MMP-9 were not significantly affected by either treatment.

CONCLUSIONS

Both E2/NETA and raloxifene increased the total and active MMP-2 serum levels. MMP-9 was not significantly affected by either regimen. Larger, long-term clinical trials are needed to elucidate the effect of HT and raloxifene on MMPs and the possible clinical implications for cardiovascular health.