Effect of raloxifene on activated protein C (APC) resistance in postmenopausal women and on APC resistance and homocysteine levels in elderly men: two randomized placebo-controlled studies.

Raloxifene, a selective estrogen receptor modulator, like hormonal replacement therapy increases the risk of venous thromboembolism in postmenopausal women. A possible explanation for the increased thrombotic risk could be an increase in acquired resistance to activated protein C (APC). In two randomized, placebo-controlled, double-blind studies we determined the effect of raloxifene on the normalized APC sensitivity ratios (nAPCsr). The nAPCsr were determined with the thrombin generation-based APC resistance test. In the first study 83 postmenopausal women (age, 51.1 +/- 2.7 years) randomly received daily 0.625 mg conjugated equine estrogen and 2.5 mg medroxyprogesterone acetate (n=17), 60 mg raloxifene (n=23), 150 mg raloxifene (n=20) or placebo (n=23) for 24 months. At baseline and after 6, 12 and 24 months the nAPCsr were measured. In the second study 30 elderly men (age, 64.4 +/- 2.4 years) randomly received 120 mg raloxifene (n=15) or placebo (n=15) for 3 months. At baseline and after 3 months the nAPCsr and fasting homocysteine levels were measured. In postmenopausal women conjugated equine estrogen/medroxyprogesterone acetate significantly increased the nAPCsr from 1.26 +/- 0.82 to 2.87 +/- 0.86 at 24 months (P <0.0005 compared with placebo). Raloxifene had no significant effect on nAPCsr compared with placebo in both women and men. The results did not change after excluding carriers of factor V Leiden. Also fasting homocysteine levels were not affected by raloxifene in the aging men. It is concluded that raloxifene, in contrast to combined hormonal replacement therapy, does not increase APC resistance.

Raloxifene and hormone replacement therapy increase arachidonic acid and docosahexaenoic acid levels in postmenopausal women.

Estrogens may affect the essential n-6 and n-3 fatty acids arachidonic acid (AA; C20:4n-6) and docosahexaenoic acid (DHA; C22:6n-3). Therefore, we investigated the long-term effects of hormone replacement therapy and raloxifene, a selective estrogen-receptor modulator, in two randomized, double-blind, placebo-controlled studies. In study I, 95 healthy, non-hysterectomized, early postmenopausal women (age range 47-59 years) received one of the following treatments: daily raloxifene 60 mg (n=24), daily raloxifene 150 mg (n=23), 0.625 mg conjugated equine estrogens (CEE) plus 2.5 mg medroxyprogesterone acetate (MPA; n=24), or placebo (n=24). In study II, 30 men (age range 60-69 years) received daily 120 mg raloxifene (n=15) or placebo (n=15). In study I, plasma cholesteryl ester fatty acids were measured at baseline and after 6, 12, and 24 months in 83 (drop out rate 13%), 73 (23%), and 70 (25%) women respectively. In study II, fatty acids were measured at baseline and after 3 months in 29 men (drop out rate 3%). In postmenopausal women, administration of 150 mg raloxifene increased AA by a mean of +6.1% (P=0.055, not significant). Administration of CEE plus MPA increased AA by +14.1% (P<0.0005). Mean changes in DHA were +22.1% (P=0.003) and +14.9% (P=0.047) respectively, as compared with placebo. In men, 120 mg raloxifene for 3 months did not significantly affect AA (-5.2%; P=0.342) or DHA (+4.0%; P=0.755), but it increased testosterone levels by +19.8% (P=0.006). Administration of raloxifene 150 mg/day as well as CEE plus MPA to postmenopausal women increases the proportion of AA and DHA in plasma cholesteryl esters during a follow-up of 2 years. Short term administration of raloxifene in elderly men did not affect AA or DHA. The synthesis of AA and DHA from precursors may be enhanced through an estrogen receptor-dependent pathway.

Raloxifene reduces procarboxypeptidase U, an antifibrinolytic marker. A 2-year randomized, placebo-controlled study in healthy early postmenopausal women.

OBJECTIVE: The aim of this study was to compare the long-term effects of two dosages of raloxifene with oral hormone therapy (HT; conjugated equine estrogens combined with medroxyprogesterone acetate) on procarboxypeptidase U. DESIGN: In a randomized, double-blind, placebo-controlled, 2-year study, 95 healthy, nonhysterectomized, early postmenopausal women received either daily raloxifene 60 mg (n = 24), raloxifene 150 mg (n = 23), HT (conjugated equine estrogens 0.625 mg + medroxyprogesterone acetate 2.5 mg, n = 24), or placebo (n = 24). At baseline and after 6, 12, and 24 months, fasting plasma procarboxypeptidase U concentrations were measured. RESULTS: Six months of treatment with raloxifene 60 mg and raloxifene 150 mg were associated with significant decreases in plasma procarboxypeptidase U concentrations, which were sustained after 12 and 24 months. Raloxifene 60 mg: t = 0, 619 +/- 89 U/L (mean +/- SD); t = 6, 574 +/- 87 U/L; t = 12, 571 +/- 96 U/L; t = 24, 568 +/- 92 U/L; ANCOVA versus placebo, P = 0.026. Raloxifene 150 mg: t = 0, 608 +/- 67 U/L; t = 6, 580 +/- 73 U/L; t = 12, 578 +/- 70 U/L; t = 24, 562 +/- 61 U/L; ANCOVA versus placebo, P = 0.039. No significant changes were found in the HT group. CONCLUSION: Long-term treatment with raloxifene reduced procarboxypeptidase U plasma concentrations.

Raloxifene treatment increases plasma levels of beta-endorphin in postmenopausal women: a randomized, placebo-controlled study.

OBJECTIVE: To evaluate the effect of the selective estrogen receptor modulator raloxifene hydrochloride (Evista, Eli Lilly and Company, Indianapolis, IN) on plasma levels of beta-endorphin, and to determine whether beta-endorphin levels and menopausal symptoms are related. DESIGN: A randomized, double-blind, placebo-controlled pilot study. SETTING: Endocrinology outpatient department. PATIENT(S): Forty postmenopausal women. INTERVENTION(S): The women received raloxifene, 60 mg/d, or placebo for 3 months. A questionnaire on climacteric symptoms was administered before and after treatment. MAIN OUTCOME MEASURE(S): Circulating levels of beta-endorphin, climacteric symptom score, and correlation with beta-endorphin levels. RESULT(S): Raloxifene treatment significantly increased levels of beta-endorphin and did not significantly affect climacteric symptoms, with the exception of worsening vasomotor symptoms. No significant relation was seen between plasma levels of beta-endorphin and climacteric symptoms. CONCLUSION(S): Raloxifene modulates plasma levels of beta-endorphin without concomitantly relieving climacteric symptoms, as seen with hormone replacement therapy.

Neither long-term treatment with raloxifene nor hormone replacement therapy modulate cardiac function in healthy postmenopausal women: two randomized, placebo-controlled, 2-year studies.

OBJECTIVE: Our purpose was to investigate the long-term effects of raloxifene, compared with opposed and unopposed estrogen replacement therapy, on echocardiographic parameters of left ventricular systolic function in healthy postmenopausal women. A total of 157 women were studied in 2 randomized, double-blind, placebo-controlled, 2-year studies. STUDY DESIGN: In study I, 60 postmenopausal women who had undergone hysterectomy received daily raloxifene, 60 mg (n = 15); raloxifene, 150 mg (n = 15); conjugated equine estrogens (CEE), 0.625 mg (n = 15); or placebo (n = 15). In study II, 97 postmenopausal women who had not undergone hysterectomy received daily raloxifene, 60 mg (n = 24); raloxifene, 150 mg (n = 24); CEE, 0.625 mg, plus medroxyprogesterone acetate (MPA), 2.5 mg (n = 24); or placebo (n = 25). M-mode, quantitative 2-dimensional and Doppler echocardiographic measurements were performed at baseline and after 1 and 2 years. RESULTS: Neither after 1 year nor after 2 years of treatment were echocardiographic parameters found to differ from baseline in both raloxifene groups, as well as in the unopposed CEE and the CEE/MPA groups, compared with the placebo group. CONCLUSION: Within 2 years of raloxifene treatment, no effect on echocardiographic parameters of left ventricular systolic function was found. Unopposed CEE or CEE/MPA also showed no effect.

A 2-year, randomized, comparative, placebo-controlled study on the effects of raloxifene on lipoprotein(a) and homocysteine.

OBJECTIVES: Lipoprotein(a) (Lp(a)) and homocysteine (Hcy) are independent cardiovascular risk factors, which have been shown to be lowered by hormone replacement therapy (HRT). In this 2-year study, the long-term effects of raloxifene (Rlx) in two doses, on Lp(a) and Hcy, were studied and compared with the effects of continuously combined hormone replacement therapy (ccHRT). METHODS: In a prospective, randomized, double-blind, placebo-controlled 2-year study, 95 healthy, non-hysterectomized, early postmenopausal women, received daily either oral Rlx 60 mg (N=24) or 150 mg (N=23), ccHRT (conjugated equine estrogens 0.625 mg plus medroxyprogesterone acetate 2.5 mg; N=24) or placebo (N=24). Fasting serum Lp(a) and plasma Hcy concentrations were measured at baseline and at 6, 12 and 24 months. RESULTS: The mean individual changes compared to baseline after 24 months were for Lp(a): Rlx 60: - 5%, Rlx 150: -7%, ccHRT: -34%, placebo: +1% and for Hcy: Rlx 60: -3%, Rlx 150: -4%, ccHRT: -4%, placebo: +6%. ANCOVA was significant for Lp(a) under ccHRT versus placebo (P=0.001) and for Lp(a) under ccHRT versus each of the two Rlx groups (P<0.05). CONCLUSIONS: Long-term treatment with Rlx was not as effective as ccHRT in lowering Lp(a). Although not significant and without an obvious dose-related response, the Hcy values showed the same trend for each treatment arm, which is in line with data reported earlier.