Sex steroid hormone polymorphisms, high-density lipoprotein cholesterol, and apolipoprotein A-1 from the Study of Women's Health Across the Nation (SWAN)

Sex-dependent associations of serum BDNF, glycolipid metabolism and cognitive impairments in Parkinson's disease with depression: a comprehensive analysis

Brain-derived neurotrophic factor (BDNF) and glycolipid metabolism have been implicated in cognitive impairments and depression among Parkinson's disease (PD). However, the role of sex differences in this relationship remains elusive. This study aimed to investigate the potential sex differences in the link between serum BDNF levels, glycolipid metabolism and cognitive performance among depressive PD patients. PD patients comprising 108 individuals with depression and 108 without depression were recruited for this study. Cognitive function was assessed using the Montreal Cognitive Assessment Beijing version (MOCA-BJ). The severity of depressive symptoms was assessed using the Hamilton Depression Rating Scale (HAMD-17), while motor symptoms were evaluated using the Revised Hoehn and Yahr rating scale (H-Y) and the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III). Laboratory testing and enzyme-linked immunosorbent assay (ELISA) are used to measure serum levels of glycolipid metabolism and BDNF. Females showed superior performance in delayed recall (all p < 0.05), male PD patients exhibited higher scores in naming tasks compared to females in non-depression group. There was no sex differences in serum BDNF levels between depression and non-depression groups. Liner regression analysis indicated BDNF as an independent risk factor for language deficits in male PD patients with depression (p < 0.05), while cholesterol (CHOL) emerged as a cognitive influencing factor, particularly in delayed recall among male PD patients with depression (p < 0.05). Our study reveals extensive cognitive impairments in PD patients with depression. Moreover, BDNF and CHOL may contribute to the pathological mechanisms underlying cognitive deficits, particularly in male patients with depression.

Gender-specific association of biochemical variables with depression: a population-based case-control study from North India

Background

Depression is a highly prevalent mental disorder with complex aetiology. An emerging body of evidence shows that depression tends to co-occur with abnormal blood glucose levels and dyslipidaemia. This study aimed to understand the overall and gender-specific associations of abnormal glucose levels and dyslipidaemia with depression in a single Mendelian population from rural Haryana, India. To achieve the aim, a population-based case-control study, which constituted of 251 depressed (cases) and 251 non-depressed (controls) individuals, was set up. The study was conducted among the Jat community of Palwal District, Haryana (North India). Data collection was done using a pre-tested interview schedule through the household survey method. Depression status was ascertained using Beck Depression Inventory-II. Fasting blood glucose analysis and lipid profiling were done using commercial kits (Randox, USA) through spectrophotometry. Statistical analysis was done using MS-Excel 2010 and SPSS version 16.0.

Results

In the present study, overall fasting blood sugar level was not found to be associated with depression. However, high blood sugar posed a 3.6-folds elevated risk for depression among females with borderline significance (p = 0.058). Further, higher levels of TC and LDL were found to be inversely associated with depression. In the sex-wise analysis inverse association of TC and LDL with depression remained significant among males but not among females. Instead, high TG and high VLDL showed an increased risk for depression in females.

Conclusions

This study suggests gender-specific associations of some of the studied biochemical variables with depression. Longitudinal studies are warranted to explicate cause-effect relationships between the studied biochemical variables and depression.

Elevated HDL Levels Linked to Poorer Cognitive Ability in Females With Parkinson's Disease

Introduction

Cholesterol levels have been associated with age-related cognitive decline, however, such an association has not been comprehensively explored in people with Parkinson's disease (PD). To address this uncertainty, the current cross-sectional study examined the cholesterol profile and cognitive performance in a cohort of PD patients.

Methods

Cognitive function was evaluated using two validated assessments (ACE-R and SCOPA-COG) in 182 people with PD from the Australian Parkinson's Disease Registry. Total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and Triglyceride (TRG) levels were examined within this cohort. The influence of individual lipid subfractions on domain-specific cognitive performance was investigated using covariate-adjusted generalised linear models.

Results

Females with PD exhibited significantly higher lipid subfraction levels (TC, HDL, and LDL) when compared to male counterparts. While accounting for covariates, HDL levels were strongly associated with poorer performance across multiple cognitive domains in females but not males. Conversely, TC and LDL levels were not associated with cognitive status in people with PD.

Conclusion

Higher serum HDL associates with poorer cognitive function in females with PD and presents a sex-specific biomarker for cognitive impairment in PD.

Sex-dependent effect of APOE on Alzheimer's disease and other age-related neurodegenerative disorders

The importance of apolipoprotein E (APOE) in late-onset Alzheimer's disease (LOAD) has been firmly established, but the mechanisms through which it exerts its pathogenic effects remain elusive. In addition, the sex-dependent effects of APOE on LOAD risk and endophenotypes have yet to be explained. In this Review, we revisit the different aspects of APOE involvement in neurodegeneration and neurological diseases, with particular attention to sex differences in the contribution of APOE to LOAD susceptibility. We discuss the role of APOE in a broader range of age-related neurodegenerative diseases, and summarize the biological factors linking APOE to sex hormones, drawing on supportive findings from rodent models to identify major mechanistic themes underlying the exacerbation of LOAD-associated neurodegeneration and pathology in the female brain. Additionally, we list sex-by-genotype interactions identified across neurodegenerative diseases, proposing APOE variants as a shared etiology for sex differences in the manifestation of these diseases. Finally, we present recent advancements in 'omics' technologies, which provide a new platform for more in-depth investigations of how dysregulation of this gene affects the development and progression of neurodegenerative diseases. Collectively, the evidence summarized in this Review highlights the interplay between APOE and sex as a key factor in the etiology of LOAD and other age-related neurodegenerative diseases. We emphasize the importance of careful examination of sex as a contributing factor in studying the underpinning genetics of neurodegenerative diseases in general, but particularly for LOAD.

Heritability and Genome-Wide Association Study of Plasma Cholesterol in Chinese Adult Twins

Dyslipidemia represents a strong and independent risk factor for cardiovascular disease. Plasma cholesterol, such as total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and high density lipoprotein cholesterol (HDL-C), is the common indicator of diagnosing dyslipidemia. Here based on 382 Chinese twin pairs, we explored the magnitude of genetic impact on TC, HDL-C, LDL-C variation and further searched for genetic susceptibility loci for them using genome-wide association study (GWAS). The ACE model was the best fit model with additive genetic parameter (A) accounting for 26.6%, common or shared environmental parameter (C) accounting for 47.8%, unique/non-shared environmental parameter (E) accounting for 25.6% for the variance in HDL-C. The AE model was the best fit model for TC (A: 61.4%; E: 38.6%) and LDL-C (A: 65.5%; E: 34.5%). While no SNPs reached the genome-wide significance level (P < 5 × 10-8), 8, 14, 9 SNPs exceeded the suggestive significance level (P < 1 × 10-5) for TC, HDL-C, LDL-C, respectively. The promising genetic regions for TC, HDL-C, LDL-C were on chromosome 11 around rs7107698, chromosome 5 around rs12518218, chromosome 2 around rs10490120, respectively. Gene-based analysis found 1038, 1033 and 1090 genes nominally associated with TC, HDL-C, LDL-C (P < 0.05), especially FAF1, KLKB1 for TC, KLKB1 for HDL-C, and NTRK1, FAF1, SNTB2 for LDL-C, respectively. The number of common related genes among TC, HDL-C and LDL-C was 71, including FAF1, KLKB1, etc. Pathway enrichment analysis discovered known related pathways-zinc transporters, metal ion SLC transporters for TC, cell adhesion molecules CAMs, IL-6 signaling for HDL, FC epsilon RI signaling pathway, NFAT pathway for LDL, respectively. In conclusion, the TC and LDL-C level is moderately heritable and the HDL-C level is lowly heritable in Chinese population. The genomic loci, functional genes and pathways are identified to account for the heritability of plasma cholesterol level. Our findings provide important insights into plasma cholesterol molecular physiology and expect future research to replicate and validate our results.

Sex differences in associations between blood lipids and cerebral small vessel disease

BACKGROUND AND AIMS

Dyslipidemia predicts higher risk of coronary events and stroke and might be associated with cerebral small vessel disease (SVD). Previous studies linking blood lipids and SVD have yielded inconsistent results, which may be attributable to sex differences in lipids metabolism. The aim of this study was to investigate the relationships between blood lipids and SVD in neurologically healthy men and women.

METHODS AND RESULTS

Consecutive 817 people aged 50 years or more were enrolled and underwent magnetic resonance imaging scans to evaluate the periventricular white matter lesions (PVWMLs), deep white matter lesions (DWMLs) and silent brain infarction (SBI). Fasting total cholesterol, triglyceride, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol, apolipoprotein A-1 (apoA-1) and apolipoprotein B were assessed. Multivariable logistic regression analyses were performed to determine the associations of blood lipids with PVWMLs, DWMLs and SBI. HDL-C (for PVWMLs: OR 0.36, 95% CI 0.19-0.71; for DWMLs: OR 0.35, 95% CI 0.20-0.63) and apoA-1 (for PVWMLs: OR 0.27, 95% CI 0.11-0.66; for DWMLs: OR 0.22, 95% CI 0.10-0.48) were inversely associated with the severity of PVWMLs and DWMLs in women but not in men after adjustment for age, hypertension, diabetes, current smoking, daily drinking, body mass index and uric acid. Additionally, no blood lipids were significantly associated with SBI.

CONCLUSIONS

Our findings demonstrate that sex differences may exist in the associations between lipids and SVD. HDL-C and apoA-1 levels were inversely associated with the severity of PVWMLs and DWMLs in women.

Sex-specific nonlinear associations between serum lipids and different domains of cognitive function in middle to older age individuals

To examine how serum lipids relates to specific cognitive ability domains between the men and women in Chinese middle to older age individuals. A complete lipid panel was obtained from 1444 individuals, ages 50-65, who also underwent a selection of cognitive tests. Participants were 584 men and 860 women from Linyi city, Shandong province. Multiple linear regression analyses examined serum lipids level as quadratic predictors of sex-specific measure of performance in different cognitive domains, which were adjusted for sociodemographic and lifestyle characteristics. In men, a significant quadratic effect of total cholesterol (TC) was identified for Digit Symbol (B = -0.081, P = 0.044) and also quadratic effect of low density lipoprotein-cholesterol (LDL-C) was identified for Trail Making Test B (B = -0.082, P = 0.045). Differently in women, there were significant quadratic associations between high density lipoprotein-cholesterol (HDL-C) and multiple neuropsychological tests. The nonlinear lipid-cognition associations differed between men and women and were specific to certain cognitive domains and might be of potential relevance for prevention and therapy of cognitive decline.

Cognitive Functions, Concentration of Endogenous Estradiol, Estrogen Receptor α (ERα) Polymorphism in Postmenopausal Women

BACKGROUND The goal of this study was to investigate the relationship between cognitive functions and the level of endogenous estradiol in postmenopausal women, according to which estrogen receptor α (ERα) polymorphism the woman carries. MATERIAL AND METHODS The study group consisted of 210 women. The inclusion criteria were: minimum 2 years after the last menstruation, FSH concentration 30 U/ml, and no dementia signs on Montreal Cognitive Assessment (MoCA). A computerized battery of Central Nervous System Vital Signs (CNS VS) test was used to diagnose cognitive functions. Genotyping of the ERa polymorphism was performed using a polymerase chain reaction and restriction enzymes (PCR-RFLP). Blood plasma was tested for FSH and estradiol (E2). Statistical analysis was performed using STATISTICA software. RESULTS A relationship was confirmed between standard scores for 3 cognitive functions: general memory, verbal memory, and processing speed, and the XbaI polymorphism in the women in the study. In the group of women with genotype TT PvuII, significant positive relationships were observed between the concentration of E2 and the standard scores of 3 cognitive functions: general memory, verbal memory, and processing speed. In the group of women with genotype TC PvuII, significant negative correlations were found between the concentration of E2 and the standard scores of 4 cognitive functions: NCI, general memory, verbal memory, and processing speed. CONCLUSIONS ERα polymorphism exerted an effect on the interaction between the concentration of estradiol and the results for cognitive functions. The concentration of estradiol did not depend on Xba1 and PvuII polymorphisms. The results for cognitive functions depended on which Xba1 polymorphism the woman carried.

Delay discounting, genetic sensitivity, and leukocyte telomere length

In a graying world, there is an increasing interest in correlates of aging, especially those found in early life. Leukocyte telomere length (LTL) is an emerging marker of aging at the cellular level, but little is known regarding its link with poor decision making that often entails being overly impatient. Here we investigate the relationship between LTL and the degree of impatience, which is measured in the laboratory using an incentivized delay discounting task. In a sample of 1,158 Han Chinese undergraduates, we observe that steeper delay discounting, indexing higher degree of impatience, is negatively associated with LTL. The relationship is robust after controlling for health-related variables, as well as risk attitude-another important determinant of decision making. LTL in females is more sensitive to impatience than in males. We then asked if genes possibly modulate the effect of impatient behavior on LTL. The oxytocin receptor gene (OXTR) polymorphism rs53576, which has figured prominently in investigations of social cognition and psychological resources, and the estrogen receptor β gene (ESR2) polymorphism rs2978381, one of two gonadal sex hormone genes, significantly mitigate the negative effect of impatience on cellular aging in females. The current results contribute to understanding the relationship between preferences in decision making, particularly impatience, and cellular aging, for the first time to our knowledge. Notably, oxytocin and estrogen receptor polymorphisms temper accelerated cellular aging in young females who tend to make impatient choices.

ESR1 and ESR2 polymorphisms in the BIG 1-98 trial comparing adjuvant letrozole versus tamoxifen or their sequence for early breast cancer

Estrogen receptor 1 (ESR1) and ESR2 gene polymorphisms have been associated with endocrine-mediated physiological mechanisms, and inconsistently with breast cancer risk and outcomes, bone mineral density changes, and hot flushes/night sweats. DNA was isolated and genotyped for six ESR1 and two ESR2 single-nucleotide polymorphisms (SNPs) from tumor specimens from 3691 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1-98 trial to receive tamoxifen and/or letrozole for 5 years. Associations with recurrence and adverse events (AEs) were assessed using Cox proportional hazards models. 3401 samples were successfully genotyped for five SNPs. ESR1 rs9340799(XbaI) (T>C) variants CC or TC were associated with reduced breast cancer risk (HR = 0.82,95% CI = 0.67-1.0), and ESR1 rs2077647 (T>C) variants CC or TC was associated with reduced distant recurrence risk (HR = 0.69, 95% CI = 0.53-0.90), both regardless of the treatments. No differential treatment effects (letrozole vs. tamoxifen) were observed for the association of outcome with any of the SNPs. Letrozole-treated patients with rs2077647 (T>C) variants CC and TC had a reduced risk of bone AE (HR = 0.75, 95% CI = 0.58-0.98, P interaction = 0.08), whereas patients with rs4986938 (G>A) genotype variants AA and AG had an increased risk of bone AE (HR = 1.37, 95% CI = 1.01-1.84, P interaction = 0.07). We observed that (1) rare ESR1 homozygous polymorphisms were associated with lower recurrence, and (2) ESR1 and ESR2 SNPs were associated with bone AEs in letrozole-treated patients. Genes that are involved in estrogen signaling and synthesis have the potential to affect both breast cancer recurrence and side effects, suggesting that individual treatment strategies can incorporate not only oncogenic drivers but also SNPs related to estrogen activity.

ESR1 polymorphisms and statin therapy: a sex-specific approach

Lipid-lowering therapy has shown a high degree of variability in clinical response and there is evidence that the variability in drug response between individuals is due to genetic factors. Thirteen single nucleotide polymorphisms (SNPs) within the ESR1 gene were evaluated with basal lipid and lipoprotein levels, as well as response to lipid-lowering therapy, in 495 hypercholesterolemic individuals of European descent receiving simvastatin or atorvastatin. Significant associations were detected between rs4870061 (P=0.040, corrected P-value (PC)=0.440), rs1801132 (P=0.002, PC=0.022) and the SNP rs3020314 (P=0.013, PC=0.143) with triglyceride (TG) baseline levels. The rs4870061 was also associated with high-density lipoprotein cholesterol (HDL-C) baseline levels (P=0.045, PC=0.495). Regarding statin efficacy, rs2234693 C/C was associated with greater HDL-C increase (P=0.037; PC=0.407) and rs3798577 T allele was associated with greater total cholesterol (TC) reduction (P=0.019; PC=0.209) and greater TG reduction (P=0.026; PC=0.286). These associations suggest that ESR1 polymorphisms are in part responsible for the TC, HDL-C and TG variation levels and this effect may be sex-specific.

Associations of estrogen receptor alpha and Beta gene polymorphisms with lipid levels and insulin resistance in men

OBJECTIVE

The association of four single nucleotide polymorphisms in estrogen receptor alpha (ESR1) and beta (ESR2) genes with lipid levels and insulin resistance in men.

DESIGN AND METHODS

Lipids, glucose, insulin and HOMA-IR were determined, in a population-based, cross-sectional, cohort of 170 apparently healthy middle-aged Greek men, along with body mass index (BMI), waist circumference (WC) and percentage of body fat content (%fat). Genotyping of ESR1 for PvuII and XbaI and ESR2 for RsaI and AluI polymorphisms was performed.

RESULTS

Associations of AluI with LDL-Chol (mean ± SD, aa 4.3 ± 1.1 vs. Aa 3.7 ± 1.0 and ΑΑ 4.2 ± 1.1, p = 0.023) and RsaI with HOMA-IR [median (IQR), RR 1.55 (0.88-2.49) vs. Rr/rr 1.69 (0.72-2.29), p = 0.032] were found. Synergistic effects of RsaI and AluI of ESR2 gene on LDL-Chol levels, %fat and WC, as well as a synergistic effect of both ESR1 and ESR2 genes on levels of TChol (p = 0.01) and LDL-Chol (p = 0.027) were also shown. These findings remained significant after adjustment for potential confounders. Significant independent associations of PvuII with %fat (mean ± SD, pp 24.6 ± 5.3 vs Pp 22.4 ± 5.2 and PP 21.2 ± 6.7, p = 0.044), and RsaI with %fat (RR 22.6 ± 5.5 vs. Rr/rr 25.2 ± 6.3, p = 0.015) and WC (mean ± SD, RR 97.4 ± 10.4 vs. Rr/rr 102.6 ± 12.6, p = 0.013) were found. Synergistic effects on %fat, between the ESR1 polymorphisms (p = 0.004), between the ESR2 polymorphisms and among all four ESR polymorphisms studied were also present.

CONCLUSIONS

ESR2 is associated with LDL-Chol levels and HOMA-IR in men independently of confounders. Body fat is affected by both genes. Furthermore, a synergistic effect of ESR1 and ESR2 on TChol, LDL-Chol and %fat, was shown.

Genetics of cardiovascular disease: Importance of sex and ethnicity

Sex differences in incidence and prevalence of and morbidity and mortality from cardiovascular disease are well documented. However, many studies examining the genetic basis for cardiovascular disease fail to consider sex as a variable in the study design, in part, because there is an inherent difficulty in studying the contribution of the sex chromosomes in women due to X chromosome inactivation. This paper will provide general background on the X and Y chromosomes (including gene content, the pseudoautosomal regions, and X chromosome inactivation), discuss how sex chromosomes have been ignored in Genome-wide Association Studies (GWAS) of cardiovascular diseases, and discuss genetics influencing development of cardiovascular risk factors and atherosclerosis with particular attention to carotid intima-medial thickness, and coronary arterial calcification based on sex-specific studies. In addition, a brief discussion of how ethnicity and hormonal status act as confounding variables in sex-based analysis will be considered along with methods for statistical analysis to account for sex in cardiovascular disease.

Gender-specific associations between lipids and cognitive decline in the elderly

The aim of this study was to examine the associations between serum lipid levels and cognitive function in a community-based sample of non-demented subjects aged 65 years and over. Participants were 2737 men and 4118 women from a population-based cohort recruited from three French cities. Visual memory, verbal fluency, psychomotor speed, and executive abilities were evaluated at baseline, and after 2, 4, and 7 years of follow-up. Lipid levels were evaluated at baseline. Multiadjusted Cox models stratified by gender were adjusted for sociodemographic and lifestyle characteristics, mental and physical health, and genetic vulnerability to dyslipidemia (apolipoprotein E and A, and cholesteryl ester transfer protein) and taking into account baseline vascular pathologies. In men, a hypercholesterolemic pattern in late-life (high total cholesterol (T-C), low HDL-C, high LDL-C levels) was associated with a 25 to 50% increased risk of decline over 7 years in psychomotor speed, executive abilities, and verbal fluency. Specific associations with low T-C and low LDL-C levels were also observed which may depend on genetic vulnerability to dyslipidemia (related to apolipoprotein A5 and cholesteryl exchange transfer protein). In contrast, in women, a 30% higher rate of decline was found in psychomotor speed with high HDL-C levels and in executive abilities with low levels of LDL-C and triglycerides, in interaction with hormonal treatment. For men and women, vascular pathologies only slightly outweighed the risk related to lipids. This suggests a complex gender-specific pattern of cognitive decline involving genetic vulnerability in men and hormonal status in women.

Estrogen receptor α is not a candidate gene for metabolic syndrome in Caucasian elderly subjects

OBJECTIVE

Variants of estrogen receptor α (ERα) have been associated with obesity, dyslipidemia, diabetes and blood pressure. The Middle East registers some of the highest rate of metabolic syndrome worldwide. The aim of this study is to investigate the relationship between metabolic syndrome, a clustered combination of these metabolic factors, and polymorphisms PvuII and XbaI of ERα in Lebanese Caucasian elderly overweight subjects.

MATERIAL/METHODS

250 Caucasian Lebanese unrelated elderly men and women, median age 71 years, were studied. ERα intronic polymorphisms variants, PvuII and XbaI diplotypes and genotypes, were examined. Associations with metabolic syndrome, defined by the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI), and its components, namely high density lipoprotein (HDL), fasting glucose levels, blood pressure, and waist circumference were evaluated in regression models.

RESULTS

ER α diplotypes and genotypes distributions were similar between participants with and without metabolic syndrome, in the overall group of subjects, and by gender. No consistent associations between the diplotypes and genotypes tested and metabolic syndrome, or its components, could be detected.

CONCLUSIONS

Genetic variants in ERα were not associated with metabolic syndrome or its components, in a group of 250 Lebanese Caucasian elderly participants, a group with a high prevalence of metabolic syndrome.

Sex differences in the associations between lipid levels and incident dementia

Cholesterol is a risk factor for developing vascular pathologies, which is in turn an important risk factor for dementia. Previous studies linking lipids and dementia have yielded inconsistent results, which may be attributable to sex differences in the etiology of both vascular disease and dementia. The aim of this study was to evaluate the associations between lipids and incident dementia in 7053 community-dwelling elderly. Dementia was diagnosed at baseline, and 2, 4, and 7-year follow-up. Multivariate Cox models stratified by sex and history of vascular pathologies at baseline were adjusted for sociodemographic, mental and physical health variables, and genetic vulnerability. In men without vascular pathologies, an increased incidence of all-cause dementia but not Alzheimer's disease (AD) was associated with high triglyceride (TG) (HR = 1.55, 95% CI = 1.04-2.32, p = 0.03) and low HDL-cholesterol levels (HR = 1.49, 95% CI = 0.99-2.23, p = 0.05). In women without vascular pathologies, low TG levels were associated with a decreased risk of AD (HR = 0.65, 95% CI = 0.43-0.97, p = 0.03). A decreased risk was also found with high TG levels which may depend on genetic vulnerability to dyslipidemia related to APOA5. For both sexes, no significant associations were found between total- or LDL-cholesterol and dementia or AD. Low HDL-cholesterol and high TG levels may be risk factors of dementia in elderly men whereas low TG is associated with decreased incident AD in women. This data suggests a complex sex-specific etiology of vascular dementia and AD.

Women's Health Initiative Hormone Therapy Trials: New insights on Cardiovascular Disease from Additional Years of Follow up

Debate and controversy surrounding the benefits and risks of menopausal hormone therapy (MHT) for prevention of cardiovascular disease has continued in the decade since the cessation of the Women's Health Initiative (WHI) hormone therapy interventions. As a result, many women and their physicians have been reluctant to turn to MHT for relief of vasomotor and other menopausal symptoms. However, several follow-up studies of WHI participants provide additional insight into clinical characteristics of women who are more likely to have favorable outcomes and lower rates of adverse events associated with MHT. This report focuses on those studies that identify characteristics and biomarkers helpful in stratifying risk for an individual. Incorporation of these factors into a benefit:risk model could assist in patient-oriented decision making regarding use of MHT. Personalizing treatment offers the potential to minimize risk and improve health outcomes.

Genetic polymorphisms associated with carotid artery intima-media thickness and coronary artery calcification in women of the Kronos Early Estrogen Prevention Study

Menopausal hormone treatment (MHT) may limit progression of cardiovascular disease (CVD) but poses a thrombosis risk. To test targeted candidate gene variation for association with subclinical CVD defined by carotid artery intima-media thickness (CIMT) and coronary artery calcification (CAC), 610 women participating in the Kronos Early Estrogen Prevention Study (KEEPS), a clinical trial of MHT to prevent progression of CVD, were genotyped for 13,229 single nucleotide polymorphisms (SNPs) within 764 genes from anticoagulant, procoagulant, fibrinolytic, or innate immunity pathways. According to linear regression, proportion of European ancestry correlated negatively, but age at enrollment and pulse pressure correlated positively with CIMT. Adjusting for these variables, two SNPs, one on chromosome 2 for MAP4K4 gene (rs2236935, β = 0.037, P value = 2.36 × 10(-06)) and one on chromosome 5 for IL5 gene (rs739318, β = 0.051, P value = 5.02 × 10(-05)), associated positively with CIMT; two SNPs on chromosome 17 for CCL5 (rs4796119, β = -0.043, P value = 3.59 × 10(-05); rs2291299, β = -0.032, P value = 5.59 × 10(-05)) correlated negatively with CIMT; only rs2236935 remained significant after correcting for multiple testing. Using logistic regression, when we adjusted for waist circumference, two SNPs (rs11465886, IRAK2, chromosome 3, OR = 3.91, P value = 1.10 × 10(-04); and rs17751769, SERPINA1, chromosome 14, OR = 1.96, P value = 2.42 × 10(-04)) associated positively with a CAC score of >0 Agatston unit; one SNP (rs630014, ABO, OR = 0.51, P value = 2.51 × 10(-04)) associated negatively; none remained significant after correcting for multiple testing. Whether these SNPs associate with CIMT and CAC in women randomized to MHT remains to be determined.

Are polymorphisms in oestrogen receptors genes associated with lipid levels in response to hormone therapy?

BACKGROUND

Polymorphisms in the oestrogen receptor 1 (ESR1) and oestrogen receptor 2 (ESR2) genes are associated with intermediate or endpoint markers of cardiovascular disease and with the efficacy of postmenopausal hormone therapy (HT). Contradictory findings have been described in the past and the role of these genetics variants remains unclear.

METHODS

A cross-sectional study was carried out with 266 postmenopausal women, of whom 115 received oral HT (HT+) and 151 did not receive any HT (HT-). We analysed three single-nucleotide polymorphisms (SNPs) in ESR1 (rs1801132, rs7757956 and rs2813544) and two in ESR2 (rs3020450 and rs7154455) and derived haplotypes with three additional polymorphisms that had been previously investigated by our group (ESR1 rs2234693 and ESR2 rs1256049 and rs4986938).

RESULTS

The ESR1 rs2813544 polymorphism was associated with low-density lipoprotein cholesterol (LDL-C) in HT+ postmenopausal women (p = 0.044; pC = 0.388), while one ESR2 gene haplotype was associated with total cholesterol (T-chol) (p = 0.015; pC = 0.090) and LDL-C in HT+ postmenopausal women (p = 0.021; pC = 0.126).

CONCLUSION

Our findings suggest that, in HT+ postmenopausal women, the rs2813544 polymorphism may influence LDL-C levels and, as previously described, ESR2 rs1256049 is associated with T-chol and LDL-C. No previous study has investigated the association of this SNP set with lipoprotein levels in women while taking into account the hormonal status of the patients.

Genetic polymorphisms in estrogen receptors and sexual dimorphism in fat redistribution in HIV-infected patients on HAART

OBJECTIVE

To investigate genetic single nucleotide polymorphisms (SNPs) in estrogen receptor-α (ERα) (ESR1, rs2234693, rs1801132, rs7757956 and rs2813544) and ERβ (ESR2, rs3020450, rs7154455 and rs4986938) genes and relate them to the adverse effects lipodystrophy, dyslipidemia and metabolic syndrome as well as to differences in their prevalence between sexes in HIV-infected individuals on HAART.

DESIGN

Cross-sectional study.

METHODS

Blood samples and anthropometric measurements were collected from 614 patients at reference services in the cities of Porto Alegre, Pelotas and Rio Grande in Brazil. The SNPs were genotyped by real-time PCR.

RESULTS

The lipodystrophy subtype frequencies in patients of different sexes showed statistically significant differences; the atrophic pattern was more prevalent in men, and the hypertrophic pattern was more prevalent in women. Furthermore, metabolic syndrome prevalence was higher in women than in men. The ESR1 rs2813544 G-allele was associated with higher measurements of several anthropometric variables in women: BMI, total subcutaneous fat and subcutaneous fat of limbs. Additionally, patients who were AA homozygous for ESR2 rs3020450 presented an increased risk for developing lipoatrophy (prevalence ratio 1.37, 95% confidence interval 1.09-1.73, P = 0.007).

CONCLUSION

Significant differences in lipodystrophy and metabolic syndrome prevalence were detected between sexes. Moreover, the ESR1 gene (rs2813544) presented significant sex-specific associations with anthropometric variables, and the ESR2 gene (rs3020450) was associated with an increased risk of developing lipoatrophy. Our results suggest that these genes are in part responsible for the sexual dimorphism in fat tissue redistribution and patterns of lipodystrophy.

Estrogen receptor alpha gene polymorphisms are associated with type 2 diabetes and fasting glucose in male subjects

The PvuII and XbaI polymorphisms of the estrogen receptor α (ER1) gene have been variably associated with type 2 diabetes (T2D) in several populations. However, this association has not been studied in Iranian subjects and we hypothesized that the ER1 variants might be associated with T2D and related metabolic traits in this population. The PvuII and XbaI genotypes were determined by PCR-RFLP in 377 normoglycemic controls and 155 T2D patients. Bonferroni correction was applied for the correction of multiple testing. No significant association was found between the allele and genotype frequencies of PvuII and XbaI variants with T2D in females. In a dominant model (PP vs. Pp+pp), the frequency of the Pp+pp genotype was higher in normoglycemic subjects compared to T2D patients [85.5% vs. 66.7%, OR 0.22 (0.08-0.55), P=0.001]. Four possible haplotypes were observed in the population, whereas haplotype TA had a higher frequency in male T2D subjects than the controls. Furthermore, non-diabetic male subjects carrying the genotype of PP had a higher fasting glucose levels than the individuals with the genotype of Pp+pp (P=0.013). Multivariate logistic regression analysis showed that PvuII polymorphism was the independent determinants of T2D in males [OR 4.37 (1.61-11.86), P=0.004]. No association was found between the XbaI polymorphism and diabetes in male group. Our results suggest that the ER1 polymorphisms might associate with T2D and fasting glucose among Iranian male subjects.

Sex-based differences in vascular function

Cardiovascular disease is the leading cause of morbidity and mortality for both men and women in the USA. However, there are differences between the sexes in age-dependent onset, severity, symptoms and outcomes. Basic research into the causes of sex-dependent differences in cardiovascular disease is ongoing and includes investigation into genetic variation in expression and distribution of receptors for the sex steroids; specificity of natural and synthetic ligands that activate the sex steroid receptors; and intracellular mechanisms that are activated by the receptors in all components of the vessel wall and blood elements, which integrate to regulate vascular tone, vascular repair and remodeling in health and disease. In this era of personalized medicine, basic research into mechanisms of sex differences in vascular function will result in improved prevention, detection and treatment of cardiovascular disease in both men and women.

The association between the rs2234693 and rs9340799 estrogen receptor alpha gene polymorphisms and risk factors for cardiovascular disease: a review

Although estrogen is primarily thought of as the hormone involved in female reproduction, it also plays a role in many additional physiological and pathological processes. Recent studies have demonstrated an association between estrogen and clustered risk factors for cardiovascular disease (CVD), such as lipid and glucose metabolism and obesity-related phenotypes, as well as occurrence and severity of CVD. Evidence suggesting a genetic basis for this link is accumulating. Several polymorphisms of the estrogen receptor (ER) alpha (ESR1) gene exist that may influence the impact of estrogen, leading to clinically relevant phenotypes. Based on the relationship ERS1 seems to exhibit with CVD risk factors, these polymorphisms may play a role in the mediation of vasoprotective effects, modulation of cardiovascular physiology, and development of risk factors for CVD. The two most frequently studied polymorphisms located in ESR1 are often identified by their restriction endonucleases Pvull (rs2234693) and Xbal (rs9340799). ln this review, we have evaluated and summarized the results of studies involving rs2234693 and rs9340799 and clustered risk factors accompanying development of CVD. Despite inconsistent findings, together these studies provide some support for a relationship between polymorphisms in ESR1 and risk factors for CVD. These summarized findings do not yet support inclusion of ESR1 genotypes in genetic testing algorithms for predisposition to CVD, but they do indicate that further investigation into the potential connection between ESR1 and risk factors for CVD is warranted.

Gender and genotype modulation of the association between lipid levels and depressive symptomatology in community-dwelling elderly (the ESPRIT study)

BACKGROUND

Lipids appear to mediate depressive vulnerability in the elderly; however, sex differences and genetic vulnerability have not been taken into account in previous prospective studies.

METHODS

Depression was assessed in a population of 1040 women and 752 men aged 65 years and older at baseline and after 7-year follow-up. Clinical level of depression (DEP) was defined as having either a score of 16 or higher on the Centre for Epidemiology Studies Depression scale or a diagnosis of current major depression on the Mini-International Neuropsychiatric Interview. Lipid levels, apolipoprotein E, and serotonin transporter linked promoter region (5-serotonin transporter gene linked promoter region) genotypes were evaluated at baseline.

RESULTS

Multivariate analyses adjusted by sociodemographic and behavioral variables, measures of physical health including ischemic pathologies, and genetic vulnerability indicated gender-specific associations between dyslipidemia and DEP, independent of the use of lipid-lowering agents or apolipoprotein E status. Men with low low-density lipoprotein cholesterol levels had twice the risk of prevalent and incident DEP, whereas in women low high-density lipoprotein cholesterol levels were found to be significantly associated with increased prevalent DEP (odds ratio = 1.5) only. A significant interaction was observed between low low-density lipoprotein-cholesterol and 5-serotonin transporter gene linked promoter region genotype, men with s/s or s/l genotype being at increased risk of DEP (odds ratio = 6.0 and 2.7, respectively). No significant gene-environment interaction was observed for women.

CONCLUSIONS

DEP is associated with higher atherogenic risk in women (low high-density lipoprotein cholesterol), whereas the reverse is observed in men (low low-density lipoprotein cholesterol). Late-life depression may have a complex gender-specific etiology involving genetic vulnerability in men.

Association of polymorphisms in genes involved in lipoprotein metabolism with plasma concentrations of remnant lipoproteins and HDL subpopulations before and after hormone therapy in postmenopausal women

OBJECTIVE

A high degree of inter-individual variability in plasma lipid level response to hormone therapy (HT) has been reported. Variations in the oestrogen receptor alpha gene (ESR1) and in genes involved in lipid metabolism may explain some of the variability in response to HT. Subjects Postmenopausal Caucasian women (n = 208) participating in a placebo-controlled randomized trial of 3.2 years of hormone therapy (HT).

METHODS

Plasma triglyceride (TG), remnant lipoprotein cholesterol (RLP-C), and high-density lipoprotein cholesterol (HDL-C) levels and HDL subpopulations were assessed at baseline and at follow up. Single nucleotide polymorphisms (SNPs) in ESR1 and in the ATP binding cassette A1 (ABCA1), cholesteryl ester transfer protein (CETP), hepatic lipase (LIPC), lipoprotein lipase (LPL), and scavenger receptor class B type I (SRB1) genes were assessed for their association with baseline plasma levels and HT-related changes in levels of RLP-C and HDL subpopulations.

RESULTS

Carriers of the ESR1 PvuII or IVS1-1505 variants had lower plasma TG concentrations and higher plasma HDL-C and alpha-1 and prealpha-1 HDL particle levels at baseline and showed greater increases in HDL-C, apo A-I and alpha-1 particle levels after HT than wild-type carriers. Carriers of the N291S and D9N variants in the LPL gene had significantly higher remnant lipoproteins and lower alpha-2 HDL particle levels at baseline. The CETP TaqIB SNP was a significant determinant of baseline plasma HDL-C and HDL subpopulation profile.

CONCLUSIONS

Single nucleotide polymorphisms in ESR1, CETP and LPL had significant effects on baseline plasma levels of TG-rich and HDL subpopulations. With the exception of ESR1 SNPs, variation in genes involved in lipid metabolism has a very modest effect on lipoprotein response to HT.

Using basic science to design a clinical trial: baseline characteristics of women enrolled in the Kronos Early Estrogen Prevention Study (KEEPS)

Observational and epidemiological studies suggest that menopausal hormone therapy (MHT) reduces cardiovascular disease (CVD) risk. However, results from prospective trials showed neutral or adverse effects most likely due to differences in participant demographics, such as age, timing of initiation of treatment, and preexisting cardiovascular disease, which reflected in part the lack of basic science information on mechanisms of action of hormones on the vasculature at the time clinical trials were designed. The Kronos Early Estrogen Replacement Study (KEEPS) is a prospective, randomized, controlled trial designed, using findings from basic science studies, to test the hypothesis that MHT when initiated early in menopause reduces progression of atherosclerosis. KEEPS participants are younger, healthier, and within 3 years of menopause thus matching more closely demographics of women in prior observational and epidemiological studies than women in the Women's Health Initiative hormone trials. KEEPS will provide information relevant to the critical timing hypothesis for MHT use in reducing risk for CVD.

Vascular actions of estrogens: functional implications

The impact of estrogen exposure in preventing or treating cardiovascular disease is controversial. But it is clear that estrogen has important effects on vascular physiology and pathophysiology, with potential therapeutic implications. Therefore, the goal of this review is to summarize, using an integrated approach, current knowledge of the vascular effects of estrogen, both in humans and in experimental animals. Aspects of estrogen synthesis and receptors, as well as general mechanisms of estrogenic action are reviewed with an emphasis on issues particularly relevant to the vascular system. Recent understanding of the impact of estrogen on mitochondrial function suggests that the longer lifespan of women compared with men may depend in part on the ability of estrogen to decrease production of reactive oxygen species in mitochondria. Mechanisms by which estrogen increases endothelial vasodilator function, promotes angiogenesis, and modulates autonomic function are summarized. Key aspects of the relevant pathophysiology of inflammation, atherosclerosis, stroke, migraine, and thrombosis are reviewed concerning current knowledge of estrogenic effects. A number of emerging concepts are addressed throughout. These include the importance of estrogenic formulation and route of administration and the impact of genetic polymorphisms, either in estrogen receptors or in enzymes responsible for estrogen metabolism, on responsiveness to hormone treatment. The importance of local metabolism of estrogenic precursors and the impact of timing for initiation of treatment and its duration are also considered. Although consensus opinions are emphasized, controversial views are presented to stimulate future research.

ESR1 polymorphism is associated with plasma lipid and apolipoprotein levels in Caucasians of the Rochester Family Heart Study

We evaluated six estrogen receptor 1 (ESR1) polymorphisms for association with ten plasma lipid and apolipoprotein traits in 1,847 individuals (941 females and 906 males) in the multi-generation Rochester Family Heart Study using a generalized estimating equation approach. Apolipoprotein A-I (apoA-I), apoA-II, and HDL-cholesterol (HDL-C) were associated with exon 4 rs1801132 (Pro325Pro) genotype (P = 0.0044, P = 0.0048, and P = 0.0035, respectively). Positive correlation between levels of apoA-I, apoA-II, and HDL-C and the number of G alleles was observed in females (P = 0.0120, P = 0.0032, and P = 0.0030), but not males (P > 0.05). Because few studies have evaluated the effect of ESR1 gene polymorphisms on lipid traits in children, we also stratified our sample at the age of 15 years. There was evidence of association between intron 1 single-nucleotide polymorphisms rs9322331 and rs9340799 and apoC-II, and triglycerides (TGs) in youths 15 years and younger. In youths, evidence of association between rs9322331 and rs9340799 and apoC-II was stronger in males (P = 0.0036 and P = 0.0124) than in females (P > 0.05), whereas evidence of association with TG was stronger in females (P = 0.0030 and P = 0.0024) than in males (P > 0.05). These findings suggest that ESR1 variation plays an age- and sex-dependent role in determining plasma lipid and apolipoprotein levels.

Identification of estrogen receptor alpha gene polymorphisms by SSCP and its effect on reproductive traits in Japanese flounder (Paralichthys olivaceus)

Estrogen receptor (ERalpha) modifies the expression of genes involved in cell growth, proliferation and differentiation through binding to estrogen response elements (EREs) located in a number of gene promoters, so the ERalpha gene is considered as an important factor affecting reproductive endocrinology in Japanese flounder (Paralichthys olivaceus). In this study, twelve single nucleotide polymorphisms (SNPs) within eight CDS exons and 1 kb of 3'-UTR of the ERalpha gene were tested to association with four reproductive traits in a population of 119 Japanese flounder individuals with polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP). The association analysis of SNPs within Japanese flounder ERalpha gene with the reproductive traits was carried out using General Linear Model (GLM) estimation. Results indicated that two SNPs in the exon4 of ERalpha gene, P1 (A803G and C864T), were significantly associated with hepatosomatic index (HSI) (P<0.05) in female Japanese flounder. Other ten SNPs in 3'-UTR associated to serum 17beta-estradiol (E(2)) and HSI showed that P2 (A1982T) was significantly associated with E(2) (P<0.01) and P3 (A2149G, 2181TTACAAG2182 insertion or deletion, T2324G, A2359G and G2391A) was significantly associated with HSI (P<0.05) in female Japanese flounder. However, P2 (A1982T) and P4 (G2256T, T2294C, T2309G and A2333T) had significant effects on E(2) (P<0.05 and P<0.01, respectively) in male Japanese flounder. In addition, there were significant associations between diplotype D1 based on fourteen SNPs and reproductive traits. The genetic effects for HSI (female) or E(2) (male) of diplotype D1 were significantly higher than those of other eight diplotypes (P<0.05), respectively. Our findings implied that P1 of ERalpha gene affecting the reproductive traits could be a potential QTN (quantitative trait nucleotide) which would be useful genetic marker in the selection of some reproductive traits for its in Japanese flounder.

Polymorphisms and haplotypes of the estrogen receptor-beta gene (ESR2) and cardiovascular disease in men and women

BACKGROUND

Cohort studies suggest an association between variation in the estrogen receptor-alpha gene (ESR1) and cardiovascular disease (CVD), but data are lacking for the effect of variation in the estrogen receptor-beta gene (ESR2).

METHODS

Three polymorphisms of the ESR2 gene, and their associated haplotypes, were evaluated in 296 white women from the Women's Health Study and 566 white men from the Physicians' Health Study who developed CVD [myocardial infarction (MI) or ischemic stroke], each matched 1:1 to a member of the cohort study who remained free from CVD. Blood samples and cardiovascular risk information were collected at baseline.

RESULTS

Women, but not men, who developed CVD or MI, but not ischemic stroke, were more likely to have the rs1271572 polymorphism variant T allele (P = 0.05 and 0.02) and less likely to have the rs1256049 polymorphism variant A allele (P = 0.003 and 0.004). No associations were observed for rs4986938. In conditional logistic multivariate regression, the rs1271572 variant was associated with increased odds of CVD [odds ratio (OR) = 1.49, 95% CI: 1.10-2.01] and MI (OR = 1.46, 95% CI: 0.96-2.23), whereas the rs1256049 variant was associated with decreased odds of CVD (OR = 0.37, 95% CI: 0.17-0.79) and MI (OR = 0.25, 95% CI: 0.09-0.73) in women. A common haplotype that included the rs1271572 variant was associated with a 7-fold increased risk of MI in women.

CONCLUSIONS

Two tightly linked polymorphisms of ESR2 were associated with risk of CVD, particularly MI, in women but not men. Additional studies of ESR2 genetic variation and risk of CVD are warranted.

Sex steroid hormone pathway genes and health-related measures in women of 4 races/ethnicities: the Study of Women's Health Across the Nation (SWAN)

We synthesized findings relating health outcomes and genetic variants of the sex steroid hormone pathway in women from the Study of Women's Health Across the Nation (SWAN) Genetics Study. The SWAN Genetics Study, a component of the longitudinal SWAN study, describes selected genetics characteristics of health-related attributes during the menopausal transition in African American, Caucasian, Chinese, and Japanese women. At baseline, SWAN recruited menstruating women aged 42 to 52 years, who were not using exogenous hormones. Immortalized cell lines were developed and genotyped in 1,538 specimens from 1,757 participants in the genetics study. Genotypes and haplotypes from 6 genes (27 single nucleotide polymorphisms [SNPs]) in the sex steroid hormone pathway were related to circulating hormone concentrations, menstrual cycle profiles, and health-related outcomes, including lipids, diabetes mellitus, depressive symptoms, measures of cognition, bone mineral density (BMD), and vasomotor symptoms. Allele frequencies and distances differed substantially in the 4 race/ethnicity-specific groups evaluated, leading to variable patterns of association with health-related measures. For example, 17HSD genotypes were highly associated with diabetes risk in Caucasian women, whereas its haplotypes were associated with diabetes risk in both African American and Caucasian women. Several SNPs were associated with multiple outcomes. ESR1 rs3798577 was significantly associated with circulating estradiol concentrations, indicators of ovarian aging, high-density lipoprotein (HDL) cholesterol, apolipoprotein A-1, insulin sensitivity, and lumbar spine BMD. CYP1A1 rs2606345 was related to estrogen metabolite concentrations, vasomotor symptoms, and depressive symptoms. Some associations were much more prominent in specific races/ethnicities; Chinese women had statistically significant relations between ESR2 rs1256030 and HDL cholesterol, lumbar spine BMD, hip BMD, and metabolic syndrome. Importantly, women in the SWAN Genetics Study were typical of women in the community-based SWAN sample. This community-based sample of women from the SWAN Genetics Study identified important genetic sex steroid hormone pathway variants in relation to measures of health status. The magnitude and breadth of these relationships should motivate further research to verify and extend the findings.