Estrogen-metabolizing gene polymorphisms and age at natural menopause in Caucasian women

L.A. Hefler1,4, C. Grimm1, G. Heinze2, C. Schneeberger1, M.W. Mueller3, A. Muendlein3, J.C. Huber1, S. Leodolter1 and C.B. Tempfer1

Departments of 1 Obstetrics and Gynecology and 2 Medical Computer Sciences, Medical University of Vienna and 3 Institute of Microbiology and Genetics, University of Vienna, Vienna, Austria

4 To whom correspondence should be addressed at: Department of Obstetrics and Gynecology, Medical University of Vienna, Waehringer Guertel 18–20, A-1090 Vienna, Austria. Email: lukas.hefler{at}meduniwien.ac.at


    Abstract
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 Acknowledgements
 References
 
BACKGROUND: Lifestyle parameters, personal history and genetic factors are thought to affect the timing of natural menopause in humans. Based on their biological function, estrogen-metabolizing gene polymorphisms have been regarded as candidate genes for early menopause. METHODS: In the present cross-sectional, multi-centre study, we analysed nine single nucleotide polymorphisms of six estrogen-metabolizing genes [three estrogen-synthesizing genes, i.e. 17-{beta}-hydroxysteroid dehydrogenase type 1 (17-{beta} HSD), cytochrome P-450 (CYP) 17 and CYP19; and three estrogen-inactivating genes, i.e. catechol-O-methyltransferase (COMT), CYP1A1 and CYP1B1] by sequencing-on-chip-technology in 1360 Caucasian women with natural menopause. Women's lifestyle parameters, reproductive and personal histories were ascertained. RESULTS: Carriage of at least one mutant allele of the CYP1B1-4 Asn453Ser A->G polymorphism (P=0.004) and the number of full-term pregnancies (P<0.001) were found to be independently associated with age at natural menopause. Women with at least one polymorphic allele of CYP1B1-4 experienced natural menopause earlier than non-carriers of the polymorphism [mean (SD) 48.6 (5.0) versus 49.4 (4.3) years]. Women with no, one, two and three or more full-term pregnancies experienced natural menopause at 48.5 (5.0), 48.8 (4.8), 49.5 (4.2) and 49.6 (4.6) years, respectively. CONCLUSION: We present the most comprehensive data on estrogen-metabolizing gene polymorphisms and timing of natural menopause to date. The number of full-term pregnancies and the CYP1B1-4 polymorphism are significant predictors of timing of natural menopause in Caucasian women.

Key words: age/estrogen/gene/natural menopause/polymorphism


    Introduction
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 Acknowledgements
 References
 
Peripheral and tissue-bound estrogen concentrations influence a woman's reproductive life span by modulating the timing of menarche and menopause. Menopause is primarily characterized by a physiological decline of hormonal production, especially estrogen and its metabolites, causing typical somatic and/or psychological alterations including hot flushes, osteoporosis, urinary tract problems, decreased libido, sleeping disorders and depression (Manson and Martin, 2001Go).

Interest in the timing of menopause and underlying processes leading to this phenomenon have gained attention in recent years. In Western societies, the average number of children per family is decreasing and women tend to postpone childbirth for career reasons. These recognized trends as well as the fact that menopause is preceded by time spans of reduced fertility further increase the interest in and relevance of factors predicting the timing of natural menopause (van Noord et al., 1997Go; Kato et al., 1998Go; Harlow and Signorello, 2000Go). Even more importantly, early menopause is regarded as a major risk factor for conditions associated with substantial health hazards such as cardiovascular diseases, ovarian cancer, osteoporosis and its associated sequelae (Gordon et al., 1978Go; van der Schouw et al., 1996Go).

The timing of menarche and menopause shows considerable variation between individuals and different societies (van Noord et al., 1997Go; Kato et al., 1998Go; Harlow and Signorello, 2000Go). Environmental, lifestyle and genetic factors may contribute alone or in specific combinations to individual variations of the reproductive life span. Data with respect to smoking, body mass index (BMI) and number of pregnancies on timing of reproductive functions are inconsistent (Bromberger et al., 1997Go; Kato et al., 1998Go; Hardy et al., 2000Go; Harlow and Signorello, 2000Go; Roth and Taylor, 2001Go).

Of note, twin studies and affected sib-pair analyses document high heritability estimates for age at menopause (Cramer et al., 1995Go; Snieder et al., 1998Go; de Bruin et al., 2001Go). Heritability has been proposed to partly explain the variation of age at natural menopause for singleton sisters. Twin data were used to distinguish additive genetic from common environmental effects (Snieder et al., 1998Go; de Bruin et al., 2001Go). Furthermore, it was shown that a family history of early menopause was associated with an increased risk for experiencing an early menopause as well (Cramer et al., 1995Go4). Multiple interacting genes are believed to influence the timing of menopause (Weel et al., 1999Go; Hefler et al., 2002Go; van Asselt et al., 2003Go). Based on their biological function, genes involved in estrogen metabolism can be seen as ‘candidate genes’ for the timing of menopause in humans.

Single nucleotide polymorphisms (SNPs) are responsible for the interindividual variation of numerous physiological functions, among them blood pressure, drug metabolism, blood clotting and cardiovascular dysfunction (Tempfer et al., 2004Go). Whereas preliminary studies have been published describing a certain influence of estrogen-metabolizing SNPs on the timing of menarche (Gorai et al., 2003Go), few data with respect to these SNPs and the timing of menopause have been published to date (Weel et al., 1999Go; Gorai et al., 2003Go).

We previously developed a microarray system combining liquid phase amplification of genomic DNA with allele-specific solid-phase PCR into a one-step reaction (Huber et al., 2002Go). We analysed nine polymorphisms within six human genes involved in estrogen metabolism (Figure 1): three estrogen-synthesizing genes, i.e. 17-{beta}-hydroxysteroid dehydrogenase type 1 (HSD17) vlV A->C, cytochrome P-450 (CYP) 17 A2 allele T->C and CYP19 aromatase (CYP19-2 Arg264Cys C->T, CYP19-3 C1558T C->T), and three estrogen inactivating-genes, i.e. catechol-O-methyltransferase (COMT) Val158Met G->A, CYP1A1 (CYP1A1-1 MspI RFLP T->C, CYP1A1-2 Ile462ValA->G) and CYP1B1 (CYP1B1-3 Leu432Val C->G, CYP1B1-4 Asn453Ser A->G). It is known that these SNPs alter gene function and subsequently influence peripheral estrogen concentrations. As estrogen is known to be crucially involved in all female reproductive processes, SNPs of these estrogen-metabolizing genes can be seen as candidate genes for timing of menopause. The nine polymorphisms were chosen after confirming the absence of any linkage disequilibrium between these specific SNPs.



View larger version (24K):
[in this window]
[in a new window]
 
Figure 1. Pathway of estrogen metabolism in the human.

 
We hypothesized that lifestyle parameters, personal history as well as SNPs involved in estrogen metabolism influence the timing of natural menopause in Caucasian women.


    Materials and methods
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 Acknowledgements
 References
 
Approval for this study was obtained by the Institutional Review Board at the Medical University of Vienna, Austria. We enrolled 1677 consecutive Caucasian women seeking counselling for various reasons, mainly for post-menopausal disorders or risk assessment for malignancies. Participating women were seen by their treating physicians in university hospitals, primary and secondary care facilities, and private offices nationwide in Germany and Austria. Signed written consent was obtained from all participating women. To avoid confounding by ethnicity, only women of Austrian and German ethnic background were included. Women were enrolled from May 2001 to March 2004.

A questionnaire asking for age at menarche and menopause, number of full-term pregnancies and miscarriages, history of recurrent abortion, age at first delivery, weight and size at menopause, smoking habits and personal history of breast cancer was answered by all participating women. Of these 1677 women, 317 women experienced surgical menopause by premenopausal hysterectomy and 1360 experienced natural menopause and were thus available for further analysis (Table I).


View this table:
[in this window]
[in a new window]
 
Table I. Characteristics of enrolled women

 
Menarche was defined as age at the first menstrual period (years); natural menopause was defined as age at the last menstrual period (years) without having menstrual periods for at least 12 consecutive months. Women with a history of perimenopausal hormone therapy use were excluded from this study, since the exact timing of natural menopause cannot be assessed in these women. DNA was extracted from patients’ blood (n=335) or buccal swabs (n=1342) and genotyping was performed according to established protocols (Huber et al., 2002Go).

Statistics
Values are given as means (SD). Student's t-test, one-way analysis of variance (ANOVA) and {chi}2 test with Bonferroni correction were used to compare lifestyle parameters and personal history between genotypes as described previously (Table II; Weel et al., 1999Go; Schuit et al., 2004Go). Allele frequencies were estimated by the gene-counting method, and the {chi}2 test was used to identify deviations from Hardy–Weinberg equilibrium. P<0.05 was considered statistically significant.


View this table:
[in this window]
[in a new window]
 
Table II. Women's characteristics broken down by presence/absence of polymorphic alleles

 
As the influence of lifestyle parameters and personal history on age at natural menopause has not been well defined to date, we decided to use the Student's t-test, one-way ANOVA and linear regression analysis to assess the influence of these parameters, i.e. age at menarche, age at first delivery, number of full-term pregnancies (0 = nullipara, 1 = one delivery, 2 = two deliveries, 3 = three or more deliveries) and miscarriages, history of recurrent abortion, BMI, smoking habits (0 = non-smoker, 1 = current smoker) and personal history of breast cancer (0 = no personal history of breast cancer, 1 = personal history of breast cancer) on age at natural menopause (Table III; Gorai et al., 2003Go). Based on the slightly varying design of the questionnaire in different study centres, smoking information was only available for 563 women.


View this table:
[in this window]
[in a new window]
 
Table III. Lifestyle parameters, personal history and age at natural menopause

 
Subsequently, we performed a multivariate linear regression model with age at natural menopause as dependent variable and the nine investigated polymorphisms as independent variables. We used a dominant genetic model [comparing carriers of at least one polymorphic allele (= homozygous mutant and heterozygous) versus non-carriers] of all nine investigated polymorphisms in all 1360 women (Table IV). Multiple imputation was used to replace all missing values (Little, 1992Go). An association was considered significant at a P<0.05 in the multivariate linear regression model.


View this table:
[in this window]
[in a new window]
 
Table IV. Multivariate linear regression analysis of age at natural menopause as dependent variable

 
A power analysis showed that except for the EDH17 polymorphism (48.7%), a power of >80% was reached for all other polymorphisms with an {alpha}=0.05 with a minimum detectable difference in timing of menopause of 2 years.

We used the statistical software SAS V9.1 (2003 SAS Institute Inc., Cary, NC) for statistical analysis.


    Results
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 Acknowledgements
 References
 
Women's characteristics are shown in Table I. Table II shows the investigated lifestyle parameters and personal history broken down by the presence/absence of polymorphic alleles. Genotype distributions were in Hardy–Weinberg equilibrium. After stepwise Bonferroni correction was performed, no significant association between any polymorphism and age at menarche, number of full-term pregnancies, age at first delivery, BMI, personal history of breast cancer, current or past smoking and personal history of recurrent abortion was ascertained.

The association between lifestyle parameters and personal history with age at menopause is depicted in Table III.

We analysed the influence of the investigated nine estrogen-metabolizing gene polymorphisms on the timing of natural menopause using a dominant genetic model in a multivariate regression analysis (Yamada et al., 2002Go). Table IV shows the results of the multivariate regression analysis. Carriage of at least one mutant allele of the CYP1B1-4 polymorphism (P=0. 018) was found to be independently associated with age at natural menopause. Women with at least one polymorphic allele of CYP1B1-4 experienced natural menopause earlier than non-carriers of the polymorphism [49.4 (4.3) versus 48.6 (5.0) years].


    Discussion
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 Acknowledgements
 References
 
Timing of menopause is one of the cornerstones of a woman's reproductive life. The role of lifestyle parameters and personal history with respect to an early onset of menopause has been discussed controversially. Data with respect to the role of increased/decreased BMI and smoking habits in determining the timing of menopause are inconsistent (Snieder et al., 1998Go; Hardy et al., 2000Go).

Smoking habits are regarded to have a major impact on a woman's life. Of note, various studies showed that the effect of smoking is dependent on numerous co-factors, such as age at the beginning of smoking, duration of smoking, number of cigarettes smoked, age at cessation of smoking, etc. (Band et al., 2002Go). Therefore, the literature with respect to the influence of smoking on human diseases is inconsistent (Band et al., 2002Go; Yamada et al., 2002Go; Gorai et al., 2003Go). In our study, data on smoking are lacking in a fraction of women. This is due to the design of the questionnaire in different study centres. Based on the number of missing values and on the information on smoking status available, it is not surprising that only a trend towards an early menopause was ascertained. An exact quantification of smoking habits, as published previously for breast cancer, would provide adequate data (Band et al., 2002Go).

Furthermore, we ascertained various parameters on women's personal history not previously correlated with timing of menopause such as a personal history of recurrent abortion and breast cancer. In a univariate analysis, a personal history of premenopausal breast cancer and the number of full-term pregnancies were significantly associated with the timing of natural menopause. These novel data support the assumption that higher lifetime estrogen exposure may be responsible for an increased risk of breast cancer as well as an increased age at natural menopause.

Our study supports previous data that the number of full-term pregnancies is associated with the timing of menopause (Harlow and Signorello, 2000Go). As it has been hypothesized that onset of menopause is attributed to the loss of ovarian follicles, pregnancy by suppressing ovulation during and shortly after pregnancy delays oocyte depletion and may subsequently postpone menopause. It might be argued that women who have a greater follicular reserve and later menopause are more likely to have more pregnancies. A selection bias cannot be fully excluded. Of note, we are only confirming previously published studies with respect to the influence of full-term pregnancies on age at menopause. Furthermore, it has been published previously that the lifetime number of ovulatory cycles (indicative of oocyte depletion) is predictive of the age at natural menopause. This assumption is also consistent with many studies that have reported early natural menopause among women with shorter menstrual cycles, and a later natural menopause among women who used oral contraceptives (Harlow and Signorello, 2000Go).

We have to acknowledge that the analysis of the number of pregnancies and the age at menopause should be time (age) dependent. Women having a late menopausal age have had the opportunity to have more children. Since decreased fertility precedes menopause, it is possible that women with an early age at menopause have fewer pregnancies. Therefore, confounding by age cannot be fully excluded.

It is interesting to note that the timing of menopause shows considerable variation between individuals and societies, and yet it shows a considerable degree of genetic control. Furthermore, there is also evidence that the age of menopause has remained static over thousands of years, while age at menarche has changed due to changes in body weight and improved nutrition. There is no adequate explanation to date for this phenomenon.

An important role for genetically determined factors for an early onset of menopause has been reported (Snieder et al., 1998Go; Weel et al., 1999Go). As described previously for myocardial infarction (Yamada et al., 2002Go), we screened for possible associations between estrogen-metabolizing gene polymorphisms and timing of natural menopause using three different genetic models. A dominant, genetic model was performed. Within the CYP1B1 gene locus, the presence of at least one mutant allele of CYP1B1-4, but not of CYP1B1-3, was found to be the only polymorphism significantly associated with age at natural menopause in our series.

The association between the CYP1B1-4 polymorphism and timing of menopause is biologically plausible. The human CYP1B1 enzyme has been shown to be an important enzyme not only in estradiol inactivation, but also in the activation of diverse procarcinogens such as nitroarenes, polycyclic aromatic hydrocarbons and arylamines to reactive metabolites that cause DNA damage (Shimada et al., 1999Go; Murray et al., 2001Go; Ingelman-Sundberg, 2004Go). The enzyme is constitutively expressed in steroidogenic tissues such as the uterus, breast and ovary (Hayes et al., 1996Go). Although the role of the CYP1B1-4 polymorphism has not been fully elucidated to date (Shimada et al., 1999Go; McLellan et al., 2000Go), experimental data suggest that CYP1B1-4 is linked to biological effects (Bailey et al., 1998Go). This is in accordance with in vivo data showing that circulating serum sex steroid levels in post-menopausal women are at least to a certain extent influenced by estrogen-metabolizing gene polymorphisms (de Vivo et al., 2002Go; Dunning et al., 2004Go). It can only be hypothesized that women with the CYP1B1-4 polymorphism have modestly increased serum estrogen levels throughout their reproductive career. In the present study, we do not have any data on serum estradiol levels, thus, we cannot correlate SNPs with hormonal levels. Furthermore, it is not known to date whether increased/decreased circulating estrogen levels throughout the reproductive phase are predictive of the timing of menopause.

Our study has some limitations. Selection bias has to be acknowledged when interpreting the results of this study. First, we had to exclude women using perimenopausal hormone replacement therapy (HRT) because these women have no clear time point of menopause. Also, we have consecutively recruited women seeking advice due to post-menopausal symptoms, a prescription of HRT and on risk assessment for malignancies. We cannot rule out bias by self-selection of women participating in the study. Furthermore, cause–effect relationships cannot be fully appreciated in a cross-sectional study.

In summary, we present the most comprehensive data on estrogen-metabolizing gene polymorphisms and timing of natural menopause to date. The presence of the CYP1B1-4 Asn453Ser A->G polymorphism is a significant predictor of the timing of natural menopause in Caucasian women.


    Acknowledgements
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 Acknowledgements
 References
 
This study was supported in part by the Ludwig Boltzmann Foundation, Institute for Gynecology and Gynecologic Oncology.


    References
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 Acknowledgements
 References
 
Bailey LR, Roodi N, Dupont WD and Parl FF (1998) Association of cytochrome P450 1B1 (CYP1B1) polymorphism with steroid receptor status in breast cancer. Cancer Res 58, 1388.

Band PR, Le ND, Fang R and Deschamps M (2002) Carcinogenic and endocrine disrupting effects of cigarette smoke and risk of breast cancer. Lancet 360, 1044–1049.[CrossRef][ISI][Medline]

Bromberger JT, Matthews KA, Kuller LH, Wing RR, Meilahn EN and Plantinga P (1997) Prospective study of the determinants of age at menopause. Am J Epidemiol 145, 124–133.[Abstract]

Cramer DW, Xu H and Harlow BL (1995) Family history as a predictor of early menopause. Fertil Steril 64, 740–745.[ISI][Medline]

de Bruin JP, Bovenhuis H, van Noord PA, Pearson PL, van Arendonk JA, te Velde ER, Kuurman WW and Dorland M (2001) The role of genetic factors in age at natural menopause. Hum Reprod 16, 2014–2018.[Abstract/Free Full Text]

de Vivo I, Hankinson SE, Li L, Colditz GA and Hunter DJ (2002) Association of CYP1B1 polymorphisms and breast cancer risk. Cancer Epidemiol Biomarkers Prev 11, 489–492.[Abstract/Free Full Text]

Dunning AM, Dowsett M, Healey CS, Tee L, Luben RN, Folkerd E, Novik KL, Kelemen L, Ogata S, Pharoah PD, Easton DF, Day NE and Ponder BA (2004) Polymorphisms associated with circulating sex hormone levels in postmenopausal women. J Natl Cancer Inst 96, 936–945.[Abstract/Free Full Text]

Gorai I, Tanaka K, Inada M, Morinaga H, Uchiyama Y, Kikuchi R, Chaki O and Hirahara F (2003) Estrogen-metabolizing gene polymorphisms, but not estrogen receptor-alpha gene polymorphisms, are associated with the onset of menarche in healthy postmenopausal Japanese women. J Clin Endocrinol Metab 88, 799–803.[Abstract/Free Full Text]

Gordon T, Kannel WB, Hjortland MC and McNamara PM (1978) Menopause and coronary heart disease The Framingham Study. Ann Intern Med 89, 157–161.[ISI][Medline]

Hardy R, Kuh D and Wadsworth M (2000) Smoking, body mass index, socioeconomic status and the menopausal transition in a British national cohort. Int J Epidemiol 29, 845–851.[Abstract/Free Full Text]

Harlow BL and Signorello LB (2000) Factors associated with early menopause. Maturitas 35, 3–9.[CrossRef][ISI][Medline]

Hayes CL, Spink DC, Spink BC, Cao JQ, Walker NJ and Sutter TR (1996) 17 beta-estradiol hydroxylation catalyzed by human cytochrome P450 1B1. Proc Natl Acad Sci USA 93, 9776–9781.[Abstract/Free Full Text]

Hefler LA, Worda C, Huber JC and Tempfer CB (2002) A polymorphism of the Nos3 gene and age at natural menopause. Fertil Steril 78, 1184–1186.[CrossRef][ISI][Medline]

Huber M, Mundlein A, Dornstauder E, Schneeberger C, Tempfer CB, Mueller MW and Schmidt WM (2002) Accessing single nucleotide polymorphisms in genomic DNA by direct multiplex polymerase chain reaction amplification on oligonucleotide microarrays. Anal Biochem 303, 25–33.[CrossRef][ISI][Medline]

Ingelman-Sundberg M (2004) Human drug metabolising cytochrome P450 enzymes: properties and polymorphisms. Naunyn Schmiedeberg's Arch Pharmacol 369, 89–104.[CrossRef][ISI][Medline]

Kato I, Toniolo P, Akhmedkhanov A, Koenig KL, Shore R and Zeleniuch-Jacquotte A (1998) Prospective study of factors influencing the onset of natural menopause. J Clin Epidemiol 51, 1290–1292.

Little R (1992) Regression with missing xs: a review. J Am Stat Assoc 87, 1127–1237.

Manson JE and Martin KA (2001) Clinical practice. Postmenopausal hormone-replacement therapy. N Engl J Med 345, 34–40.[Free Full Text]

McLellan RA, Oscarson M, Hidestrand M, Leidvik B, Jonsson E, Otter C and Ingelman-Sundberg M (2000) Characterization and functional analysis of two common human cytochrome P450 1B1 variants. Arch Biochem Biophys 378, 175–181.[CrossRef][ISI][Medline]

Murray GI, Melvin WT, Greenlee WF and Burke MD (2001) Regulation, function, and tissue-specific expression of cytochrome P450 CYP1B1. Annu Rev Pharmacol Toxicol 41, 297–316.[CrossRef][ISI][Medline]

Roth LK and Taylor HS (2001) Risks of smoking to reproductive health. Assessment of women's knowledge. Am J Obstet Gynecol 184, 934–939.[CrossRef][ISI][Medline]

Schuit SC, van Meurs JB, Bergink AP, van der Klift M, Fang Y, Leusink G, Hofman A, van Leeuwen JP, Uitterlinden AG and Pols HA (2004) Height in pre- and postmenopausal women is influenced by estrogen receptor alpha gene polymorphisms. J Clin Endocrinol Metab 89, 303–309.[Abstract/Free Full Text]

Shimada T, Watanabe J, Kawajiri K, Sutter TR, Guengerich FP, Gillam EM and Inoue K (1999) Catalytic properties of polymorphic human cytochrome P450 1B1 variants. Carcinogenesis 20, 1607–1613.[Abstract/Free Full Text]

Snieder H, MacGregor AJ and Spector TD (1998) Genes control the cessation of a woman's reproductive life: a twin study of hysterectomy and age at menopause. J Clin Endocrinol Metab 83, 1875–1880.[Abstract/Free Full Text]

Tempfer CB, Schneeberger C and Huber JC (2004) Applications of polymorphisms and pharmacogenomics in obstetrics and gynecology. Pharmacogenomics 5, 57–65.[CrossRef][ISI][Medline]

van Asselt KM, Kok HS, Peeters PH, Roest M, Pearson PL, te Velde ER, Grobbee DE and van der Schouw YT (2003) Factor V Leiden mutation accelerates the onset of natural menopause. Menopause 10, 477–481.[CrossRef][ISI][Medline]

van der Schouw YT, van der Graaf Y, Steyerberg EW, Eijkemans JC and Banga JD (1996) Age at menopause as a risk factor for cardiovascular mortality. Lancet 347, 714–718.[CrossRef][ISI][Medline]

van Noord PA, Dubas JS, Dorland M, Boersma H and te Velde E (1997) Age at natural menopause in a population-based screening cohort: the role of menarche, fecundity, and lifestyle factors. Fertil Steril 68, 95–102.[CrossRef][ISI][Medline]

Weel AE, Uitterlinden AG, Westendorp IC, Burger H, Schuit SC, Hofman A, Helmerhorst TJ, van Leeuwen JP and Pols HA (1999) Estrogen receptor polymorphism predicts the onset of natural and surgical menopause. J Clin Endocrinol Metab 84, 3146–3150.[Abstract/Free Full Text]

Yamada Y, Izawa H, Ichihara S, Takatsu F, Ishihara H, Hirayama H, Sone T, Tanaka M and Yokota M (2002) Prediction of the risk of myocardial infarction from polymorphisms in candidate genes. N Engl J Med 347, 1916–1923.[Abstract/Free Full Text]

Submitted on October 10, 2004; resubmitted on February 14, 2005; accepted on February 16, 2005.





This Article
Abstract
Full Text (PDF )
All Versions of this Article:
20/5/1422    most recent
deh848v1
Alert me when this article is cited
Alert me if a correction is posted
Services
Email this article to a friend
Similar articles in this journal
Similar articles in ISI Web of Science
Similar articles in PubMed
Alert me to new issues of the journal
Add to My Personal Archive
Download to citation manager
Request Permissions
Google Scholar
Articles by Hefler, L.A.
Articles by Tempfer, C.B.
PubMed
PubMed Citation
Articles by Hefler, L.A.
Articles by Tempfer, C.B.