The effect of estrogen replacement therapy on total plasma homocysteine in healthy postmenopausal women

Effects of early initiated oestrogen replacement therapy on plasma homocysteine levels in women in surgically induced menopause

OBJECTIVE

The aim of this study was to investigate and to compare the effects on serum homocysteine levels of early initiated oral and transdermal oestrogen replacement therapies (ERTs) given to women without a uterus who had undergone surgically induced menopause. Homocysteine levels are considered one of the predictors of cardiovascular disease risk.

METHODS

This study included 45 women with surgical menopause. Of 45 women, 15 received oral ERT, (oestradiol hemihydrate 2 mg/day, Estrofem®), 15 received transdermal ERT (oestradiol hemihydrate 0.1% gel 1.5 mg/day, Estreva®) and 15 received no hormone therapy. Blood samples were collected from all women to measure homocysteine levels at the mean time of 15 weeks after surgical menopause. Obtained results of the groups were compared.

RESULTS

There were no significant differences in age, height, weight, body mass index (BMI), waist circumference and time elapsing since menopause between the three groups. The duration of ERT was not significantly different between the therapy groups. There was no significant difference in homocysteine levels between the groups (p>0.05). No significant correlation was found between weight, BMI and homocysteine levels (p>0.05).

CONCLUSION

Considering that homocysteine is a predictor of risk for cardiovascular disease, the results of this study showed that early initiation of ERT in healthy surgically induced menopausal women neither protects nor deteriorates cardiovascular disease.

Effects of low- or high-dose hormone therapy on fasting and post-methionine homocysteine levels in postmenopausal women

OBJECTIVE

To evaluate the effect of two different hormone therapy (HT) doses on fasting and post-methionine homocysteine levels, an independent risk factor for cardiovascular and thromboembolic diseases.

METHODS

Forty-eight women in natural postmenopause randomly received calcium 1 mg/day (control group; n = 12) or calcium plus low dose (1 mg estradiol plus 0.5 mg norethisterone; n = 18) or high dose (2 mg estradiol plus 1 mg norethisterone; n = 18) HT in a 6-month randomized, controlled, prospective study.

RESULTS

Folate levels did not vary in any group, while levels of vitamin B12 significantly decreased after low- (-12.2 +/- 6.6%; p < 0.04) or high-dose HT (-13.9 +/- 6.1%; p < 0.01). Fasting homocysteine was reduced by either HT dose in a way that was inversely related to pretreatment homocysteine levels (-0.675x; r = 0.644; p < 0.0001). Modification of post-load homocysteine increase was influenced by the HT dose and inversely related to the homocysteine response to methionine observed at baseline. The regression slope observed with the low-dose HT (-1.637x; r = 0.57; p < 0.02) was significantly steeper (p < 0.001) than that observed with the high-dose HT (-0.304x; r = 0.554; p < 0.03) dose.

CONCLUSIONS

Low- or high-dose HT similarly influences fasting homocysteine levels. Low-dose HT seems to be more effective than high-dose HT in reducing the post-methionine homocysteine increase.

The effects of raloxifene and tibolone on homocysteine and vascular histopathological changes

The aim of the present study was to examine the effects of raloxifene (RLX) and tibolone (TBN) on plasma homocysteine (Hcy) levels and their relationship with atherosclerotic changes in the walls of the carotid artery in ovariectomised rats. Thirty surgically ovariectomised Wistar albino rats after a menopausal period of 6 cycles were randomly assigned to receive RLX 0.01 mg/kg/day (n=10), TBN 0.04 mg/kg/day (n=10) and the same dose of placebo (n=10) for 6 cycles. Serum levels of vitamin B12, folate and Hcy were measured and carotid arteries were examined histopathologically following the termination of treatment. Hcy levels were 3.27+/-0.97, 2.57+/-0.32 and 2.28+/-0.12 micromol/l, Vitamin B12 levels were 901.90+/-239.76, 694.70+/-112.20 and 631+/-309.44 pg/ml and folate levels were 73.80+/-12.71, 72.51+/-7.05 and 84.79+/-20.82 ng/ml in receiving RLX, TBN and placebo respectively. Hcy levels were increased by RLX vs. placebo (P=0.006) but not by TBN vs. placebo (P=0.070). Vitamin B12 levels were found to be elevated by TBN vs. the control group (P=0.041) but not by RLX vs. placebo (P=0.059). Histopathological examination of carotid arteries from rats receiving both RLX and TBN revealed no difference vs. placebo. Data obtained from the study support the view that neither RLX nor TBN appears to have a primary protective effect on vascular disease by effecting the metabolism of Hcy at menopause.

Impact of folate and homocysteine metabolism on human reproductive health

Folates belong to the vitamin B group and are involved in a large number of biochemical processes, particularly in the metabolism of homocysteine. Dietary or genetically determined folate deficiency leads to mild hyperhomocysteinemia, which has been associated with various pathologies. Molecular mechanisms of homocysteine-induced cellular dysfunction include increased inflammatory cytokine expression, altered nitric oxide bioavailability, induction of oxidative stress, activation of apoptosis and defective methylation. Whereas the involvement of folate metabolism and homocysteine in ageing-related diseases, in several developmental abnormalities and in pregnancy complications has given rise to a large amount of scientific work, the role of these biochemical factors in the earlier stages of mammalian reproduction and the possible preventive effects of folate supplementation on fertility have, until recently, been much less investigated. In the present article, the possible roles of folates and homocysteine in male and female subfertility and related diseases are systematically reviewed, with regard to the epidemiological, pathological, pharmacological and experimental data of the literature from the last 25 years.

Hyperhomocysteinemia and cardiovascular risk in postmenopausal women: the role of folate supplementation

In the postmenopausal period, cardiovascular diseases are a frequent chronic condition leading to high risk of myocardial infarction and death. Recently hyperhomocysteinemia and even mildly elevated plasma concentrations of homocysteine have been recognized as independent risk factors for vascular damage predisposing to arteriosclerosis. Elevated plasma levels of homocysteine induce vascular endothelial damage and are frequently associated with low folate levels.

In this review we evaluate literature data on some aspects related to menopause and homocysteine metabolism. In particular, we show the effect of folic acid supplementation on homocysteine concentrations and on homocysteine-related thiols, such as cysteine and cysteine-glycine, as well as the relationship with glucose, insulin, and lipidic metabolism in postmenopausal women. We also analyze the influence of folate supplementation on endothelial function, by brachial artery flow-mediated dilatation (endothelium-dependent) and nitroglycerine-induced dilatation (endothelium-independent) before and after a methionine load.

Folate administration in postmenopausal women is able to reduce high plasma homocysteine levels and to modify impaired endothelial function induced by hyperhomocysteinemia.

Clin Chem Lab Med 2007;45:130–5.

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.

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.

Hormone replacement influences homocysteine levels in the methionine-loading test: a randomized placebo controlled trial in postmenopausal women

OBJECTIVE

To investigate the mechanism by which exogenous oestrogen influences the homocysteine metabolism in postmenopausal women.

STUDY DESIGN

A randomized placebo controlled trial in which a methionine-loading test was performed, in 25 healthy postmenopausal women, before and after a 12-week oral treatment with placebo or daily 4 mg 17beta-estradiol with (HRT) or without (ERT) 10 mg dydrogesterone. Fasting and post-load homocysteine as well as Vitamins B(6), B(12) and folate were determined.

RESULTS

In both treatment groups a significant 12% decrease in fasting homocysteine was observed. This decrease was accompanied by a post-load homocysteine increase of more than 20%. Vitamin B(6) values were decreased by more than 25%.

CONCLUSION

The hormone therapy induced lowering of fasting homocysteine and Vitamin B(6) levels and an increase in post-load homocysteine, supporting the hypothesis that homocysteine-methionine metabolism is modulated by hormone therapy in postmenopausal women.

Effects of oral and transdermal 17 beta-estradiol combined with progesterone on homocysteine metabolism in postmenopausal women: a randomised placebo-controlled trial

Mild hyperhomocysteinemia is a risk factor for both ischaemic heart disease and venous thromboembolism. The effects of transdermal estrogen replacement therapy (ERT) on homocysteine metabolism in postmenopausal women have scarcely been investigated. This clinical trial aimed to estimate the effects of combined hormone replacement therapy on the fasting total homocysteine levels according to the estrogen route of administration. We enrolled 196 postmenopausal women, who were randomly allocated to receive on a continuous basis either 1mg of 17 beta-estradiol orally (n = 63) or 50 microg transdermally (n = 68) per day, both combined with a daily intake of 100 mg progesterone, or placebo (n = 65) over a period of 6 months. Neither oral nor transdermal ERT significantly affected total plasma homocysteine levels or red-blood cell folate levels. However, oral ERT significantly decreased plasma vitamin B12 levels compared to placebo (mean relative variation difference over 6 months between oral ERT and placebo: -11.7% (95%CI, -21 to -2%) whereas transdermal ERT did not display any significant effects. Our data show that transdermal ERT as well as low dose of oral ERT does not significantly affect the homocysteine metabolism. This finding does not support a role for transdermal estrogen in the prevention of ischaemic heart disease in postmenopausal women.

Effect of hormone replacement therapy and tibolone on serum total homocysteine levels in postmenopausal women

OBJECTIVE

To assess the effect of continuous combined hormone replacement therapy (HRT) or tibolone on serum total homocysteine (tHcy) levels in postmenopausal women.

STUDY DESIGN

Ninety-five postmenopausal women aged 41-68 years were included in the study. Seventy-three women with climacteric complaints, osteopenia or osteoporosis received either conjugated equine estrogens 0.625 mg combined with medroxyprogesterone acetate 5 mg (CEE/MPA, n=31) or tibolone 2.5 mg (n=42). Twenty-two healthy women, matched for chronological and menopausal age, served as controls. Serum tHcy levels were assessed at baseline, 6, 12 and 18 months.

RESULTS

No difference was recorded between groups regarding demographic characteristics or mean baseline serum tHcy. Serum tHcy levels decreased significantly in the CEE/MPA compared to baseline (change at 18 months: -3.9%, P<0.05). The magnitude of the decrease was higher in the subgroup of women with baseline tHcy levels above the median (change at 18 months: -15.0%, P<0.01). No change in tHcy levels was detected in the tibolone group throughout the study period, either in the whole group (change at 18 months: 1.9%, NS) or in the subgroup with baseline tHcy levels above the median (change at 18 months: -3.23%, NS).

CONCLUSION

Continuous CEE/MPA reduces tHcy especially in women with high pretreatment tHcy levels. Tibolone has no effect on serum tHcy levels at least during the first 18 months of therapy. Larger studies with longer follow-up are required to confirm these results.

Folate, homocysteine levels, methylenetetrahydrofolate reductase (MTHFR) 677C --> T variant, and the risk of myocardial infarction in young women: effect of female hormones on homocysteine levels

In young women data are limited about the association between myocardial infarction (MI) and hyperhomocysteinemia, low folate or methylenetetrahydrofolate reductase (MTHFR) genotypes. The effect of oral contraceptive (OC) use on plasma homocysteine levels is not clear. We assessed the association between hyperhomocysteinemia, low folate, MTHFR 677TT mutation and risk of MI, and we investigated the effect of OC use on homocysteine levels in controls. In 181 patients with a first MI and 601 controls 18-49 years of age from a population-based case-control study, non-fasting blood samples were available. The homozygote mutant allele (TT) was detected in 12% of the patients and in 10% of controls. The odds ratio (OR) for MI in TT patients compared with the wild-type (CC) controls was 1.3 [95% confidence interval (CI) 0.8, 2.3]. For all MTHFR genotypes combined, the OR for MI in the lowest quartile of folate (<5.4 nmol L-1) compared with the highest quartile (>10.4 nmol L-1) was 3.0 (95% CI 1.7, 5.1). A 2-fold increased risk of MI was found in women with the TT genotype who had folate levels below the median of 7.4 nmol L-1 compared with CC genotype and folate levels above the median (OR = 2.0; 95% CI 1.0, 3.7). Mean homocysteine levels were 12.2 micromol L-1 in OC users and 12.3 micromol L-1 in non-users. Only at the 97.5 percentile (cut-off 21.0 micromol L-1) was the adjusted OR for higher vs. lower homocysteine levels increased by 2.8-fold (95% CI 1.2, 6.8). Low folate is a risk factor for MI, particularly in women with the MTHFR 677TT genotype. Homocysteine levels were not influenced by OC use.

Comparison of the effect of oral and transdermal hormone therapy on fasting and postmethionine homocysteine levels

OBJECTIVE

To compare the modifications on basal and post-methionine homocysteine (Hcy) levels induced by transdermal vs. oral continuous combined hormone therapy (HT).

DESIGN

Prospective randomized study.

SETTING

Outpatient service at university hospital.

PATIENT(S)

Twenty-four healthy postmenopausal women.

INTERVENTION(S)

Six-month administration of transdermal (50 microg/d of E(2) and 140-170 microg/d of norethisterone [NET] acetate; n = 12) or oral (2 mg of E(2) and 1 mg of NET acetate; n = 12) HT.

MAIN OUTCOME MEASURE(S)

Fasting levels of Hcy, cysteine (Cys), folate, and vitamin B12. Post-methionine Hcy concentrations.

RESULT(S)

During HT, a slight decrease of fasting Hcy (8.9 [6.7; 15.2] micromol/L vs. 8.3 [4.9; 12.0] micromol/L) and fasting Hcy/Cys, a possible index of Hcy trans-sulfuration (0.061 [0.039; 0.107] micromol/L vs. 0.048 [0.032; 0.093] micromol/L) was observed. Modifications were similar in the transdermal and oral group. Net decreases of Hcy and Hcy/Cys observed during HT were related linearly to pretreatment values (r = 0.821 and r = 0.775, respectively), and were significant for Hcy above, but not below, 9 micromol/L. Transdermal (33.5 [27.5; 75.9] micromol/L vs. 28.4 [17.4; 48.9] micromol/L) or oral HT (36.1 [17.7; 74.8] micromol/L vs. 29.9 [17.5; 50.3] micromol/L), decreased, similarly, post-methionine Hcy levels.

CONCLUSION(S)

Similarly to oral, transdermal HT reduces post-methionine Hcy and fasting Hcy when it is elevated.

Effects of tibolone on plasma homocysteine levels in postmenopausal women

OBJECTIVE

To investigate the effects of tibolone on levels of plasma homocysteine, an independent risk factor for cardiovascular disorders, in postmenopausal women.

DESIGN

Prospective, randomized clinical study.

SETTING

University hospital.

PATIENT(S)

Postmenopausal healthy women.

INTERVENTION(S)

Tibolone (2.5 mg/d) or calcium (1250 mg/d) and conjugated equine estrogens (0.625 mg/d) plus medroxyprogesterone acetate (5 mg/d) were administered orally for 6 months. Blood samples were collected at the start and the end of therapy.

MAIN OUTCOME MEASURE(S)

Plasma homocysteine levels.

RESULT(S)

Administration of tibolone and calcium caused only a 4% decrease in plasma homocysteine levels compared with initial levels. In contrast, conjugated equine estrogens plus medroxyprogesterone acetate caused a 29% decrease in plasma homocysteine levels.

CONCLUSION(S)

Despite the reported beneficial effect of tibolone on the serum lipid profile, tibolone had no statistically significant effect on serum homocysteine levels in postmenopausal women. The possible cardiovascular protective role of tibolone might be unrelated to its effects on homocysteine levels.

Effect of long-term hormone replacement therapy on plasma homocysteine in postmenopausal women: a randomized controlled study

OBJECTIVE

The purpose of this study was to investigate the long-term effect of hormone replacement therapy on total homocysteine and to study whether there was any difference in effect between opposed and unopposed hormone replacement therapy or whether the methylenetetrahydrofolate reductase C677T polymorphism was associated with the effect of hormone replacement therapy on total homocysteine.

STUDY DESIGN

Two hundred nine healthy postmenopausal women were randomized to hormone replacement therapy (n = 103) or no substitution (n = 106) 5 to 7 years earlier.

RESULTS

Women who received hormone replacement therapy had significantly lower total homocysteine concentrations than women in the control group; median total homocysteine values were 8.6 micromol/L and 9.7 micromol/L, respectively, in a per-protocol analysis (P =.02). The effect was comparable in all methylenetetrahydrofolate reductase genotypes, and no difference between unopposed and opposed hormone replacement therapy could be demonstrated. Similar results were obtained when an intention-to-treat analysis was performed.

CONCLUSION

Long-term hormone replacement therapy results in lower total homocysteine concentrations in all methylenetetrahydrofolate reductase genotypes without demonstrable difference in effect between unopposed and opposed hormone replacement therapy.

Drugs affecting homocysteine metabolism: impact on cardiovascular risk

Elevated total plasma homocysteine has been established as an independent risk factor for thrombosis and cardiovascular disease. A strong relationship between plasma homocysteine levels and mortality has been reported in patients with angiographically confirmed coronary artery disease. Homocysteine is a thiol containing amino acid. It can be metabolised by different pathways, requiring various enzymes such as cystathionine beta-synthase and methylenetetrahydrofolate reductase. These reactions also require several co-factors such as vitamin B6 and folate. Medications may interfere with these pathways leading to an alteration of plasma homocysteine levels. Several drugs have been shown to effect homocysteine levels. Some drugs frequently used in patients at risk of cardiovascular disease, such as the fibric acid derivatives used in certain dyslipidaemias and metformin in type 2 (non-insulin-dependent) diabetes mellitus, also raise plasma homocysteine levels. This elevation poses a theoretical risk of negating some of the benefits of these drugs. The mechanisms by which drugs alter plasma homocysteine levels vary. Drugs such as cholestyramine and metformin interfere with vitamin absorption from the gut. Interference with folate and homocysteine metabolism by methotrexate, nicotinic acid (niacin) and fibric acid derivatives, may lead to increased plasma homocysteine levels. Treatment with folate or vitamins B6 and B12 lowers plasma homocysteine levels effectively and is relatively inexpensive. Although it still remains to be demonstrated that lowering plasma homocysteine levels reduces cardiovascular morbidity, surrogate markers for cardiovascular disease have been shown to improve with treatment of hyperhomocystenaemia. Would drugs like metformin, fibric acid derivatives and nicotinic acid be more effective in lowering cardiovascular morbidity and mortality, if the accompanying hyperhomocysteinaemia is treated? The purpose of this review is to highlight the importance of homocysteine as a risk factor, and examine the role and implications of drug induced modulation of homocysteine metabolism.

Continuous combined hormone replacement therapy with oral 17beta-estradiol and norethisterone acetate improves homocysteine metabolism in postmenopausal women

OBJECTIVE

To evaluate the effect of a continuous combined oral hormone replacement therapy (HRT) on basal and post-methionine load homocysteine levels in postmenopausal women.

DESIGN

Twenty-two postmenopausal women (PMW) were randomly allocated to receive either continuous combined oral HRT (2 mg of estradiol plus 1 mg of norethisterone acetate; n = 11) or no treatment (controls, n = 11) for 6 months. A methionine oral load (0.1 g/kg body weight) was performed in each subject at time 0 and after 6 months. Serum homocysteine levels were measured by high-performance liquid chromatography in samples collected at time 0 and at 4, 8, and 24 h after the methionine load, while levels of vitamin B6 (by high-performance liquid chromatography) and B12 and folate (both by ELISA) were assayed in samples collected at time 0.

RESULTS

Serum levels of glucose and body mass index increased in treated PMW, whereas folate decreased in controls. In treated PMW, basal homocysteine tended to decrease (10.6 +/- 3.3 micromol/L vs. 9.62 +/- 2.8 micromol/L, p = 0.062), whereas in controls it significantly increased (10.7 +/- 2.65 micromol/L vs. 12.17 +/- 3.89 micromol/L, p < 0.05). This increase was not significant after correction for vitamin status (p = 0.072). Homocysteine values 4 h (31.9 +/- 13.53 micromol/L vs. 39.83 +/- 22.53 micromol/L, p < 0.05) and 8 h (35.1 +/- 13.13 vs. 43.34 +/- 22.15 micromol/L) after methionine, and integrated homocysteine response to methionine (392.5 +/- 133.8 micromol/24 h vs. 458.8 +/- 104.8 micromol/24 h; p < 0.05), were significantly reduced in HRT-treated, but not in untreated, PMW.

CONCLUSIONS

Continuous combined oral HRT with17beta-estradiol plus norethisterone acetate reduces homocysteine levels, mainly after a methionine load. This effect seems to be independent of vitamin status and may have positive implications for the prevention of cardiovascular diseases in PMW.

[Influence of menopausal status in homocysteine plasma levels]

BACKGROUND

Some studies have found that postmenopausal women have increased plasma homocysteine levels while others do not. The aim of this study was to know if homocysteine levels are increased in Spanish postmenopausal women.

PATIENTS AND METHODS

In 100 postmenopausal women (age: mean [SD] 56 [6] years) homocysteine, creatinine, folic acid, vitamin B12 and lipoproteins were determined. Controls were 50 premenopausal women (age: 29 [6] years), 50 men with similar age to postmenopausal women, and 50 men with similar age to premenopausal women. All the subjects of the study were healthy.

RESULTS

Homocysteine concentrations were higher in postmenopausal compared with premenopausal women (8.6 [2.1]; 95% confidence interval [CI], 8.2-9.1 vs 7.7 [1.6]; 95% CI, 7.2-8.1 micromol/l; p < 0.05), but were not different between both men groups. Hyperhomocysteinemia was found in 9 postmenopausal but in any premenopausal women (9% vs 0%; p = 0.03). Low density lipoprotein cholesterol values were higher (155 [32]; 95% CI, 148-161 vs 111 [32]; 95% CI, 101-120 mg/dl; p < 0.05), and high density lipoprotein cholesterol lower (54 [12]; 95% CI, 52-57 vs 64 [18]; 95% CI, 59-69 mg/dl; p < 0.05) in postmenopausal than premenopausal women. In postmenopausal women homocysteine levels were negatively associated with folic acid and positively associated with creatinine levels, but there was not association with age, vitamin B12 serum levels and lipoproteins.

CONCLUSION

In postmenopausal women increased homocysteine concentrations, together with hypercholesterolemia, could contribute to the raise of their cardiovascular risk.

Acute renal vein thrombosis, oral contraceptive use, and hyperhomocysteinemia

Oral contraceptive use and hyperhomocysteinemia are considered to be relatively weak risk factors for venous thromboembolism. We report a case of acute renal vein thrombosis, a rare and aggressive form of thromboembolism, that occurred in a 21-year-old woman taking oral contraceptives, who was subsequently found to have marked hyperhomocysteinemia. This case suggests that the oral contraceptive and hyperhomocysteinemia may interact in a synergistic manner in the pathogenesis of thrombosis. In oral contraceptive users who develop venous thrombosis in the absence of other risk factors, clinicians should consider investigations for an underlying prothrombotic biochemical disorder.