A comparative study of the effect of continuous combined conjugated equine estrogen plus medroxyprogesterone acetate and tibolone on blood coagulability

The differential effect of estrogen, estrogen–progestin and tibolone on coagulation inhibitors in postmenopausal women

OBJECTIVES

Hormone therapy increases the risk of venous thromboembolism, possibly through a negative effect on coagulation inhibitors. The aim of the study was to assess the effect of conjugated equine estrogens alone or in combination with medroxyprogesterone acetate, low-dose 17beta-estradiol combined with norethisterone acetate and tibolone on inhibitors of coagulation.

METHODS

Two hundred and sixteen postmenopausal women received orally either conjugated equine estrogens 0.625 mg (CEE, n=24) or tibolone 2.5 mg (n=24) or CEE+medroxyprogesterone acetate 5 mg (CEE/MPA, n=34) or 17beta-estradiol 1 mg+norethisterone acetate 0.5 mg (E2/NETA, n=66) or no therapy (control, n=68) for 12 months. Plasma antithrombin, protein C and total protein S were measured at baseline and at 12 months.

RESULTS

CEE, CEE/MPA and E2/NETA treatment were associated with a significant decrease in antithrombin levels (CEE: baseline 235.6+/-47.6 mg/l, follow-up 221.3+/-48.3 mg/l, p=0.0001; CEE/MPA: baseline 251.1+/-38.6 mg/l, follow-up 225.0+/-42.6 mg/l, p=0.009; E2/NETA: baseline 257.1+/-59.4 mg/l, follow-up 227.1+/-50.4 mg/l, p=0.007; tibolone: baseline 252.6+/-62.4 mg/l, follow-up 261.9+/-59.1 mg/l, p=0.39). Protein C decreased significantly in the CEE and CEE/MPA groups (CEE: baseline 3.64+/-1.17 mg/l, follow-up 2.48+/-1.47 mg/l, p=0.004; CEE/MPA: baseline 3.24+/-1.23 mg/l, follow-up 2.61+/-1.38 mg/l, p=0.001; E2/NETA: baseline 3.24+/-1.10 mg/l, follow-up, 3.15+/-1.11 mg/l, p=0.08; tibolone: baseline 3.26+/-1.25 mg/l, follow-up 3.09+/-1.32 mg/l, p=0.37). Protein S decreased significantly only in the CEE/MPA group (CEE: baseline 19.4+/-2.76 mg/l, follow-up 18.0+/-2.45 mg/l, p=0.56; CEE/MPA: baseline 18.4+/-3.42 mg/l, follow-up 14.5+/-3.43 mg/l, p=0.005; E2/NETA: baseline 19.0+/-3.11 mg/l, follow-up 19.5+/-3.43 mg/l, p=0.18; tibolone: baseline 18.5+/-3.09 mg/l, follow-up 18.0+/-4.09 mg/l, p=0.32).

CONCLUSIONS

Estrogen and estrogen-progestin therapy are associated with a reduction in coagulation inhibitors, the extent of which depends on the regimen administered. Tibolone appears to have no effect on inhibitors of coagulation.

Atheroprotective effects of methotrexate on reverse cholesterol transport proteins and foam cell transformation in human THP-1 monocyte/macrophages

OBJECTIVE

To determine whether methotrexate (MTX) can overcome the atherogenic effects of cyclooxygenase 2 (COX-2) inhibitors and interferon-gamma (IFNgamma), both of which suppress cholesterol efflux protein and promote foam cell transformation in human THP-1 monocyte/macrophages.

METHODS

Message and protein levels of the reverse cholesterol transport proteins cholesterol 27-hydroxylase and ATP-binding cassette transporter A1 (ABCA1) in THP-1 cells were evaluated by real-time polymerase chain reaction and immunoblot, respectively. Expression was evaluated in cells incubated in the presence or absence of the COX-2 inhibitor NS398 or IFNgamma, with and without MTX. Foam cell transformation of lipid-laden THP-1 macrophages was detected with oil red O staining and light microscopy.

RESULTS

MTX increased 27-hydroxylase message and completely blocked NS398-induced down-regulation of 27-hydroxylase (mean +/- SEM 112.8 +/- 13.1% for NS398 plus MTX versus 71.1 +/- 4.3% for NS398 alone; P < 0.01). MTX also negated COX-2 inhibitor-mediated down-regulation of ABCA1. The ability of MTX to reverse inhibitory effects on 27-hydroxylase and ABCA1 was blocked by the adenosine A2A receptor-specific antagonist ZM241385. MTX also prevented NS398 and IFNgamma from increasing transformation of lipid-laden THP-1 macrophages into foam cells.

CONCLUSION

This study provides evidence supporting the notion of an atheroprotective effect of MTX. Through adenosine A2A receptor activation, MTX promotes reverse cholesterol transport and limits foam cell formation in THP-1 macrophages. This is the first reported evidence that any commonly used medication can increase expression of antiatherogenic reverse cholesterol transport proteins and can counteract the effects of COX-2 inhibition. Our results suggest that one mechanism by which MTX protects against cardiovascular disease in rheumatoid arthritis patients is through facilitation of cholesterol outflow from cells of the artery wall.

Tibolone in postmenopausal women with systemic lupus erythematosus: a pilot study

OBJECTIVE

To determine the influence of the use of tibolone on the frequency of flares of systemic lupus erythematosus (SLE) in postmenopausal patients.

METHODS

Thirty patients with inactive or controlled SLE were included in the study. Patients were randomized to receive a 12-month course of either tibolona (2.5 mg/day) or placebo. The following were investigated: hypoestrogenism symptoms by Kupperman index, weight; anti-dsDNA antibodies; SLE flares (frequency) assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI); and biochemical profile (total cholesterol, high-density lipoprotein cholesterol [HDL-C], triglycerides, complement components [C3/C4], alpha1-acid glycoprotein, urea, creatinine, 24-h proteinuria, C-reactive protein and erythrocyte sedimentation rate).

RESULTS

The reduction in Kupperman index was greater in the patients using tibolone than in those using placebo. The mean SLEDAI was not different between the groups during the study as well as SLE flare frequency (tibolone: 2/15 [13.3%] vs. placebo: 1/15 [6.7%]; p=0.54). All cases of flares were considered mild to moderate. Although the groups were similar at the baseline evaluation, after 6 and 12 months of treatment lower values were found in the tibolone group for triglycerides (6 months: 161.6+/-30.9 mg/dl vs. 194.4+/-46.5; p=0.04; 12 months 163.7+/-29.8 mg/dl vs. 204.1+/-49.9 mg/dl; p=0.02; tibolone vs. placebo group, respectively) and for HDL-C (6 months: 40.7+/-10.7 mg/dl vs. 53.4+/-16.5; p=0.02; 12 months: 47.2+/-7.9 mg/dl vs. 63.2+/-16.3mg/dl; p<0.01; tibolone vs. placebo group, respectively). There were no differences between the two groups in any of the remaining variables.

CONCLUSION

In patients with inactive or stable SLE, the short-term use of tibolone did not significantly affect the frequency of flares. In addition, tibolone was well tolerated and effective to control hypoestrogenism related symptoms in SLE patients.