Sex differences in coronary heart disease. Why are women so superior? The 1995 Ancel Keys Lecture

Gender differences in effectiveness of the Complete Health Improvement Program (CHIP)

OBJECTIVE

To determine the differential effect of gender on outcomes of the Complete Health Improvement Program, a chronic disease lifestyle intervention program.

DESIGN

Thirty-day cohort study.

SETTING

One hundred thirty-six venues around North America, 2006 to 2009.

PARTICIPANTS

A total of 5,046 participants (33.5% men, aged 57.9 ± 13.0 years; 66.5% women, aged 57.0 ± 12.9 years).

INTERVENTION

Diet, exercise, and stress management.

MAIN OUTCOME MEASURES

Body mass index, diastolic blood pressure, systolic blood pressure, lipids, and fasting plasma glucose (FPG).

ANALYSIS

The researchers used t test and McNemar chi-square test of proportions, at P < .05.

RESULTS

Reductions were significantly greater for women for high-density lipoprotein (9.1% vs 7.6%) but greater for men for low-density lipoprotein cholesterol (16.3% vs 11.5%), total cholesterol (TC) (13.2% vs 10.1%), triglycerides (11.4% vs 5.6%), FPG (8.2% vs 5.3%), body mass index (3.5% vs 3%), diastolic blood pressure (5.5% vs 5.1%), and TC/high-density lipoprotein (6.3% vs 1.4%) but not different for systolic blood pressure (6% vs 5%). The greatest reductions were in participants with the highest baseline TC, low-density lipoprotein, triglycerides, and FPG classifications.

CONCLUSIONS AND IMPLICATIONS

The Complete Health Improvement Program effectively reduced chronic disease risk factors among both genders, but particularly men, with the largest reductions occurring in individuals at greatest risk. Physiological or behavioral factor explanations, including differences in adiposity and hormones, dietary intake, commitment and social support, are explored. Researchers should consider addressing gender differences in food preferences and eliciting commitment and differential support modes in the development of lifestyle interventions such as the Complete Health Improvement Program.

The prevalence of cardiopulmonary symptoms among Chinese older adults in the Greater Chicago area

BACKGROUND

Cardiovascular and pulmonary symptoms influence health and well-being among older adults. However, minority aging populations are often underrepresented in most studies on cardiovascular and pulmonary symptoms. This study aims to examine the prevalence of cardiovascular and pulmonary symptoms among U.S. Chinese older adults.

METHODS

Data were drawn from the Population Study of Chinese Elderly study, a population-based survey of U.S. Chinese older adults in the Greater Chicago area. Guided by a community-based participatory research approach, a total of 3,159 Chinese older adults aged 60 and above were surveyed. Clinical Review of Systems was used to assess participants' perceptions of their cardiovascular and pulmonary symptoms.

RESULTS

Cardiovascular symptoms (31.6%) and pulmonary symptoms (42.2%) were commonly experienced by U.S. Chinese older adults. Symptoms such as cough (27.4%), sputum production (22.7%), chest pain or discomfort (16.3%), shortness of breath at rest (15.1%), and shortness of breath with activity (12.9%) were commonly reported. Older age, lower income, fewer years residing in the community, poorer self-perceived health status and quality of life, and worsened health over the last year were associated with report of any cardiovascular or pulmonary symptom.

CONCLUSIONS

Cardiovascular and pulmonary symptoms are common among Chinese older adults in the U.S. Future longitudinal research is needed to examine changes in Chinese older adults' burden of cardiopulmonary symptoms and their health and well-being.

Sex-dependent influence of endogenous estrogen in pulmonary hypertension

RATIONALE

The incidence of pulmonary arterial hypertension is greater in women, suggesting estrogens may play a role in the disease pathogenesis. Experimentally, in males, exogenously administered estrogen can protect against pulmonary hypertension (PH). However, in models that display female susceptibility, estrogens may play a causative role.

OBJECTIVES

To clarify the influence of endogenous estrogen and sex in PH and assess the therapeutic potential of a clinically available aromatase inhibitor.

METHODS

We interrogated the effect of reduced endogenous estrogen in males and females using the aromatase inhibitor, anastrozole, in two models of PH: the hypoxic mouse and Sugen 5416/hypoxic rat. We also determined the effects of sex on pulmonary expression of aromatase in these models and in lungs from patients with pulmonary arterial hypertension.

MEASUREMENTS AND MAIN RESULTS

Anastrozole attenuated PH in both models studied, but only in females. To verify this effect was caused by reduced estrogenic activity we confirmed that in hypoxic mice inhibition of estrogen receptor α also has a therapeutic effect specifically in females. Female rodent lung displays increased aromatase and decreased bone morphogenetic protein receptor 2 and Id1 expression compared with male. Anastrozole treatment reversed the impaired bone morphogenetic protein receptor 2 pathway in females. Increased aromatase expression was also detected in female human pulmonary artery smooth muscle cells compared with male.

CONCLUSIONS

The unique phenotype of female pulmonary arteries facilitates the therapeutic effects of anastrozole in experimental PH confirming a role for endogenous estrogen in the disease pathogenesis in females and suggests aromatase inhibitors may have therapeutic potential.

Prevalence of dyslipidemia and its association with insomnia in a community based population in China

Background

Studies of the prevalence of dyslipidemia and its association with insomnia are scarce in China. This study investigated the prevalence of dyslipidemia and its association with insomnia in a community based Chinese population.

Methods

We conducted a cross-sectional survey in Beijing and recruited 10054 participants aged ≥18 years. The association between self-reported insomnia and dyslipidemia was determined by multiple logistic regression models. Age, gender, education, obesity, body mass index, physical activity, current smoking, current drinking, diabetes, and hypertension were adjusted as confounders. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were reported as effect measurements.

Results

The prevalence of dyslipidemia in those with no insomnia, occasional insomnia, and frequent insomnia were 53.3%, 54.3%, and 54.5% in men and 52.0%, 54.8%, and 61.2% in women. Compared with subjects with no insomnia, the multivariate adjusted ORs and 95% CIs for those with occasional insomnia and frequent insomnia were 1.07(0.86 ~ 1.34) and 1.19(0.89 ~ 1.60) for men, and 1.00(0.86 ~ 1.14) and 1.23(1.03 ~ 1.47) for women.

Conclusions

These observations indicate that frequent insomnia was associated with a higher prevalence of dyslipidemia in women. This association was not significant in men.

WITHDRAWN: Gender differences and age-specific associations between Body Mass Index and other cardiovascular risk factors in CMV infected and uninfected people

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.imlet.2014.09.010. The duplicate article has therefore been withdrawn.

Gender differences and age-specific associations between body mass index and other cardiovascular risk factors in CMV infected and uninfected people

Body mass index (BMI) is a known risk factor for cardiovascular disease and cancer. It is also related to white blood count (WBC) and inflammation. The effects of age and gender on these associations have not been explored. Here we have examined the relationships between BMI and inflammatory parameters/cardiovascular risk factors including WBC/neutrophil count (NC), CRP and mean arterial blood pressure (MAP), in young (20-35 years) and older (60-85 years) healthy donors with respect to gender and CMV IgG serology. In young but not older people significant associations between BMI and WBC were observed, however, with opposite directions in the two genders. Only in CMV+ older women a positive trend was preserved. Across the population, there was no significant association between NC and MAP; however, among older men we saw a positive correlation between the two parameters. Linear regression confirmed that across the whole population, age group (young versus older) and also the interaction between gender and age group but not gender alone had significant effects on this association. When analysing CMV+ older people separately we established that both NC and its interaction with gender had a significant effect on MAP. This study reveals that the correlations between common inflammatory markers/cardiovascular risk factors depend on age, gender, and CMV status in a complex fashion. Our findings support the need to evaluate risk factors independently in men and women and to take into account CMV infection status. More focused studies will be required to shed light on these novel findings.

Endothelial C-type natriuretic peptide maintains vascular homeostasis

The endothelium plays a fundamental role in maintaining vascular homeostasis by releasing factors that regulate local blood flow, systemic blood pressure, and the reactivity of leukocytes and platelets. Accordingly, endothelial dysfunction underpins many cardiovascular diseases, including hypertension, myocardial infarction, and stroke. Herein, we evaluated mice with endothelial-specific deletion of Nppc, which encodes C-type natriuretic peptide (CNP), and determined that this mediator is essential for multiple aspects of vascular regulation. Specifically, disruption of CNP leads to endothelial dysfunction, hypertension, atherogenesis, and aneurysm. Moreover, we identified natriuretic peptide receptor-C (NPR-C) as the cognate receptor that primarily underlies CNP-dependent vasoprotective functions and developed small-molecule NPR-C agonists to target this pathway. Administration of NPR-C agonists promotes a vasorelaxation of isolated resistance arteries and a reduction in blood pressure in wild-type animals that is diminished in mice lacking NPR-C. This work provides a mechanistic explanation for genome-wide association studies that have linked the NPR-C (Npr3) locus with hypertension by demonstrating the importance of CNP/NPR-C signaling in preserving vascular homoeostasis. Furthermore, these results suggest that the CNP/NPR-C pathway has potential as a disease-modifying therapeutic target for cardiovascular disorders.

Correlates of reactive hyperemic index in men and postmenopausal women

The aim of the present study was to investigate the differences in digital reactive hyperemic index (RHI) in men and postmenopausal women. We investigated the differences in and correlates of RHI, measured by peripheral artery tonometry (PAT), in a group of 82 men (mean age ± SD: 55.6 ± 8.2 years; body mass index: 29.0 ± 4.2 kg/m(2)) and 125 postmenopausal women (58.9 ± 5.2 years; 27.7 ± 4.1 kg/m(2)). We also examined fRHI values (natural log of the PAT ratio of the 90-120 seconds post-occlusion interval) and augmentation index (AIx) as a measure of arterial stiffness. We found that RHI, fRHI and AIx were significantly lower in men compared to postmenopausal women (p<0.0001). We also found that fRHI values were significantly lower in individuals with (MetS+) versus without (MetS-) the metabolic syndrome (MetS). Endothelial inflammation was present in MetS+ subjects as indicated by increased plasma soluble intercellular adhesion molecule-1 (sICAM-1) (p<0.001) and E-selectin (p=0.0519) concentrations compared to MetS- individuals. No significant difference was found in RHI or AIx between MetS+ versus MetS- individuals. In summary, our study reveals that men have an impairment of endothelial function, assessed by digital PAT, compared to postmenopausal women. Furthermore, we show that the presence of the MetS is characterized by endothelial dysfunction, as suggested by lower fRHI, as well as by endothelial inflammation, which likely contributes to the increased cardiovascular disease risk associated with the MetS. ClinicalTrials.gov Identifier: NCT01085019.

Insomnia and its association with hypertension in a community-based population in China: a cross-sectional study

OBJECTIVE

To investigate the prevalence of hypertension and its association with insomnia in a community-based population in China.

METHODS

A cross-sectional study which recruited 10 054 participants aged ≥18 years was conducted in Beijing. The association between self-reported insomnia and hypertension was determined by multiple logistic regression models. Age, gender, education, obesity, body mass index, physical activity, current smoking, current drinking, work stress, diabetes and dyslipidaemia were adjusted for as confounders. Prevalence ratios (PRs) with corresponding 95% CIs were reported as effect measurements.

RESULTS

The number of subjects with no insomnia, occasional insomnia and frequent insomnia was 7632 (75.9%), 1545 (15.4%) and 877 (8.7%), respectively. The prevalence of hypertension in those with no insomnia, occasional insomnia and frequent insomnia was 37.3%, 43.0% and 48.0%. Compared with subjects with no insomnia, the multivariate adjusted PRs and 95% CIs for those with occasional insomnia and frequent insomnia were 1.01 (0.91 to 1.12) and 0.92 (0.83 to 1.03) for men and 1.08 (1.00 to 1.16) and 1.12 (1.02 to 1.22) for women.

CONCLUSIONS

Self-reported insomnia is associated with a higher risk of hypertension in women.

Cardiovascular disease in transsexual persons treated with cross-sex hormones: reversal of the traditional sex difference in cardiovascular disease pattern

OBJECTIVE

The incidence of heart disease increases with age, but is lower in women than in men up to 75 years. A protective effect of female sex hormones or, alternatively, acceleration in male heart disease by testosterone at younger ages, could explain this sex difference. In contrast with the above, male-to-female transsexual subjects (MtoF) treated with estrogens (+anti-androgens) show more cardiovascular pathology than female-to-male transsexual subjects (FtoM) receiving testosterone. Why MtoF suffer more frequently from cardiovascular disease than females is as yet unclear. The mode of cross-sex hormone treatment may be a factor, and, if so, it may need adaptations.

SUBJECTS AND METHODS

Studies in transsexual people on the effects of cross-sex hormone treatment on surrogate cardiovascular risks and on clinical endpoints were reviewed. With regard to MtoF, a parallel was sought with men with prostate cancer, undergoing androgen deprivation and estrogen administration.

RESULTS

Exposure of FtoM to testosterone was not associated with a strong increase in cardiovascular events. Aging and pre-existing cardiovascular pathology contributed to the risk of cardiovascular disease in MtoF. Use of the synthetic biopotent compound ethinyl estradiol in a dose two to four times of oral contraceptives increased cardiovascular risk substantially. The route of administration of estrogens (oral vs transdermal) may have impacted on the risks.

CONCLUSION

MtoF should not be treated with oral ethinyl estradiol. Transdermal estrogens are probably safer than oral estrogens. Pre-existing cardiovascular risks should be taken into consideration when prescribing and choosing the type of estrogens in cross-sex hormone administration (oral vs transdermal). In addition, risk factors, as they emerge with aging, should be addressed.

Testosterone and cardiovascular disease

PURPOSE OF REVIEW

Use of testosterone among men is increasing rapidly. Low serum testosterone is positively associated with cardiovascular disease and its risk factors. No large randomized controlled trial (RCT) has assessed the effects of testosterone on cardiovascular outcomes. Here recent evidence accumulating from other sources - pharmacoepidemiology, Mendelian randomization studies and meta-analysis of small RCTs - is reviewed to inform current testosterone usage.

RECENT FINDINGS

In a large, well conducted pharmacoepidemiology study specifically testosterone prescription was associated with myocardial infarction. Two Mendelian randomization studies did not corroborate beneficial effects of higher endogenous testosterone on cardiovascular risk factors, but suggested higher endogenous testosterone raised LDL cholesterol and lowered HDL cholesterol. A comprehensive meta-analysis of RCTs summarizing 27 trials including 2994 men found increased risk of cardiovascular-related events on testosterone (odds ratio 1.54, 95% confidence interval 1.09-2.18).

SUMMARY

Contrary to expectations from observational studies, current indications suggest testosterone causes ischemic cardiovascular disease with corresponding implications for practice. A large RCT would undoubtedly settle the issue definitively. Given mounting evidence of harm and the urgency of the situation assembling all the evidence from completed RCTs of testosterone or androgen deprivation therapy and use of Mendelian randomization might generate a definitive answer most quickly.

Estrogen and the female heart

Estrogen has a plethora of effects in the cardiovascular system. Studies of estrogen and the heart span human clinical trials and basic cell and molecular investigations. Greater understanding of cell and molecular responses to estrogens can provide further insights into the findings of clinical studies. Differences in expression and cellular/intracellular distribution of the two main receptors, estrogen receptor (ER) α and β, are thought to account for the specificity and differences in responses to estrogen. Much remains to be learned in this area, but cellular distribution within the cardiovascular system is becoming clearer. Identification of GPER as a third ER has introduced further complexity to the system. 17β-estradiol (E2), the most potent human estrogen, clearly has protective properties activating a signaling cascade leading to cellular protection and also influencing expression of the protective heat shock proteins (HSP). E2 protects the heart from ischemic injury in basic studies, but the picture is more involved in the whole organism and clinical studies. Here the complexity of E2's widespread effects comes into play and makes interpretation of findings more challenging. Estrogen loss occurs primarily with aging, but few studies have used aged models despite clear evidence of differences between the response to estrogen deficiency in adult and aged animals. Thus more work is needed focusing on the effects of aging vs. estrogen loss on the cardiovascular system.

Men benefit more from midlife leisure-time physical activity than women regarding the development of late-life disability--results of the KORA-Age study

OBJECTIVE

Encouraging physical activity is an important public health measure to reduce disability prevalence in the aged. The aims of this study were to determine the association between midlife physical activity and late-life disability and to investigate gender-specific differences.

METHOD

This data originates from the KORA-Age cohort, a follow-up in 2008 of the MONICA (Multinational Monitoring of Trends and Determinants in Cardiovascular Diseases)/KORA (Cooperative Health Research in the Region of Augsburg) S1-S4 surveys (1984-2001) situated in Augsburg, a city in Southern Germany. We applied a multivariable hurdle model to investigate the association of physical activity and disability.

RESULTS

We analysed 3333 persons with a mean follow-up of 18±5.5 years. Using hurdle models, moderate activity and high activity had a protective effect on the occurrence of disability (OR (odds ratio)=0.80 and 0.73), but not on severity (i.e. number of limitations). We observed a strong gender-specific difference in this association, with men benefitting more from exercise.

CONCLUSION

Elevated physical activity reduces the risk of becoming disabled and postpones the onset of disability by several years, but we could not show an effect on the severity of disability. In addition, men seem to benefit more from leisure-time physical activity than women.

Estrogens increase cystathionine-γ-lyase expression and decrease inflammation and oxidative stress in the myocardium of ovariectomized rats

OBJECTIVE

Hydrogen sulfide (H2S), generated in the myocardium predominantly via cystathionine-γ-lyase (CSE), is cardioprotective. The objectives of the present study were to investigate the effects of estrogens on CSE expression and H2S generation in the myocardium and to examine whether serum 17β-estradiol (E2) level is associated with CSE activity and H2S generation and whether H2S or E2 level is associated with proinflammatory cytokines and oxidative stress status.

METHODS

Ovariectomized Sprague-Dawley rats received subcutaneous E2 (30 μg/kg/d) or vehicle for 12 weeks. At the end of the 12-week treatment, CSE expression, H2S generation, reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, catalase (CAT) activity, interleukin (IL)-6 concentration, and tumor necrosis factor-α (TNF-α) concentration in the left ventricle were determined.

RESULTS

E2 increased CSE expression and H2S generation in the myocardium of ovariectomized rats. H2S production rate and serum E2 were positively correlated. E2 increased GSH/GSSG ratio, T-AOC, CAT, and SOD activity but decreased IL-6 and TNF-α levels. Serum E2 level was positively correlated with GSH/GSSG ratio, T-AOC, CAT, and SOD activity, and inversely correlated with IL-6 and TNF-α levels. H2S generation rate was positively correlated with T-AOC and GSH/GSSG ratio, and inversely correlated with IL-6 and TNF-α levels.

CONCLUSIONS

E2 increases CSE expression and endogenous H2S generation in the myocardium. The effects of E2 are associated with decreased oxidative stress and inflammatory status. Our data suggest that estrogens might exert cardioprotective effects through up-regulation of CSE expression and H2S generation.

Sexually dimorphic actions of glucocorticoids: beyond chromosomes and sex hormones

Sexual dimorphism is a well-documented phenomenon that is observed at all levels of the animal kingdom. Historically, sex hormones (testosterone and estrogen) have been implicated as key players in a wide array of pathologies displaying sexual dimorphism in their etiology and progression. While these hormones clearly contribute to sexually dimorphic diseases, other factors may be involved in this phenomenon as well. In particular, the stress hormone cortisol exerts differential effects in both males and females. The underlying molecular basis for the sexually dimorphic actions of glucocorticoids is unknown but clearly important to understand, since synthetic glucocorticoids are the most widely prescribed medication for the treatment of chronic inflammatory diseases and hematological cancers in humans.

Gender differences in non-glycemic responses to improved insulin sensitivity by pioglitazone treatment in patients with type 2 diabetes

Excess cortisol and GH induce insulin resistance, a central feature of type 2 diabetes (T2D). To study whether the insulin sensitizer pioglitazone affects basal cortisol levels and the GH-IGF-I axis in patients with T2D. Forty-eight patients with T2D (men/women = 28:20, age 61 ± 1 years, BMI 31 ± 0.6 kg/m(2)) were treated for 26 weeks with pioglitazone 30-45 mg daily in addition to their preexisting therapy. Insulin, proinsulin, HbA(1c), IGF-I, IGFBP-1, and basal cortisol were analyzed before and after treatment. Pioglitazone decreased proinsulin/insulin ratio and HbA(1c) decreased (HbA(1c) from 7.8 ± 0.2 to 6.6 ± 0.2% in men and from 7.6 ± 0.2 to 6.1 ± 0.2% in women, p < 0.001 in both). There was a redistribution of fat but no change in waist circumference. IGF-I and adiponectin increased (p ≤ 0.001) in both genders. IGFBP-1 increased but significantly only for the whole group (p = 0.033). Triglycerides decreased significantly in women only (p = 0.015). Before treatment, women had lower basal cortisol (p = 0.045). Basal cortisol increased in women (from 390 ± 26 to 484 ± 32 nmol/L, p = 0.020) but not in men and did not differ between genders at week 26. ΔIGFBP-1 correlated with Δcortisol (r = 0.458; p = 0.049) and Δadiponectin (r = 0.600; p = 0.005) in women only. In addition to the known effect of improving insulin sensitivity, pioglitazone increased IGF-I regardless of gender and in women also increased basal cortisol. Increased IGF-I may contribute to improved insulin sensitivity after treatment. There seems to be gender differences in treatment responses to pioglitazone on lipid metabolism and basal cortisol, perhaps correcting different mechanisms of insulin resistance between genders.

The number of X chromosomes influences protection from cardiac ischaemia/reperfusion injury in mice: one X is better than two

AIM

Sex differences in coronary heart disease have been attributed to sex hormones, whereas the potential role of the sex chromosomes has been ignored so far. Here, we investigated the role of the sex chromosomes in causing sex differences in myocardial ischaemia/reperfusion (I/R) injury.

METHODS AND RESULTS

We used two unique mouse models, the 'four core genotypes' [XX mice with ovaries (XXF) or testes (XXM) and XY mice with ovaries (XYF) or testes (XYM)] and XY* (gonadal male or female mice with one or two X chromosomes). All mice were gonadectomized (GDX). In vivo or isolated Langendorff-perfused hearts were subjected to I/R injury. The in vivo infarct size in XY mice was significantly smaller than XX mice regardless of their gonadal type (24.5 ± 4.1% in XYF and 21.8 ± 3.3% in XYM vs. 37.0 ± 3.2% in XXF and 35.5 ± 2.1% in XXM, P < 0.01). Consistent with the results in vivo, the infarct size was markedly smaller and cardiac functional recovery was significantly better in XY mice compared with XX ex vivo. The mitochondrial calcium retention capacity was significantly higher in XY compared with XX mice (nmol/mg protein: XXF = 126 ± 9 and XXM = 192 ± 45 vs. XYF = 250 ± 56 and XYM = 286 ± 51, P < 0.05). In XY* mice, mice with 2X chromosomes had larger infarct size (2X females = 41.4 ± 8.9% and 2X males = 46.3 ± 9.5% vs. 1X females = 23.7 ± 3.9% and 1X males = 26.6 ± 6.9%, P < 0.05) and lower heart functional recovery, compared with those with 1X chromosome. Several X genes that escape X inactivation (Eif2s3x, Kdm6a, and Kdm5c) showed higher expression in XX than in XY hearts.

CONCLUSION

XX mice have higher vulnerability to I/R injury compared with XY mice, which is due to the number of X chromosomes rather than the absence of the Y chromosome.

Influence of sex differences on microRNA gene regulation in disease

Sexual dimorphism is observed in most human diseases. The difference in the physiology and genetics between sexes can contribute tremendously to the disease prevalence, severity, and outcome. Both hormonal and genetic differences between males and females can lead to differences in gene expression patterns that can influence disease risk and course. MicroRNAs have emerged as potential regulatory molecules in all organisms. They can have a broad effect on every aspect of physiology, including embryogenesis, metabolism, and growth and development. Numerous microRNAs have been identified and elucidated to play a key role in cardiovascular diseases, as well as in neurological and autoimmune disorders. This is especially important as microRNA-based tools can be exploited as beneficial therapies for disease treatment and prevention. Sex steroid hormones as well as X-linked genes can have a considerable influence on the regulation of microRNAs. However, there are very few studies highlighting the role of microRNAs in sex biased diseases. This review attempts to summarize differentially regulated microRNAs in males versus females in different diseases and calls for more attention in this underexplored area that should set the basis for more effective therapeutic strategies for sexually dimorphic diseases.

Markers of Systemic Inflammation and Apo-AI Containing HDL Subpopulations in Women with and without Diabetes

Background. Besides their role in reverse cholesterol transport, HDL particles may affect the atherosclerotic process through the modulation of subclinical inflammation. HDL particles differ in size, composition, and, probably, anti-inflammatory properties. This hypothesis has never been explored in diabetic women, frequently having dysfunctional HDL. The potential relationship between lipid profile, Apo-AI containing HDL subclasses distribution, and common inflammatory markers (hsCRP, IL-6) was examined in 160 coronary heart disease- (CHD-) free women with and without type 2 diabetes. Results. Compared to controls, diabetic women showed lower levels of the atheroprotective large α-1, α-2, and pre-α-1 and higher concentration of the small, lipid-poor α-3 HDL particles (P < 0.05 all); diabetic women also had higher hsCRP and IL-6 serum levels (age- and BMI-adjusted P < 0.001). Overall, HDL subclasses significantly correlated with inflammatory markers: hsCRP inversely correlated with α-1 (P = 0.01) and pre-α-1 (P = 0.003); IL-6 inversely correlated with α-1 (P = 0.003), α-2 (P = 0.004), and pre-α-1 (P = 0.002) and positively with α-3 HDL (P = 0.03). Similar correlations were confirmed at univariate regression analysis. Conclusions. More atheroprotective HDL subclasses are associated with lower levels of inflammatory markers, especially in diabetic women. These data suggest that different HDL subclasses may influence CHD risk also through the modulation of inflammation.

Sex differences in type 2 diabetes: focus on disease course and outcomes

BACKGROUND

Women with type 2 diabetes (T2D) are less likely to reach the goals for hemoglobin A1c compared with men, and have higher all-cause mortality. The risk of cardiovascular disease is elevated among both men and women with T2D, however, the risk has declined among men over recent years while it remains stationary in women. Reasons for these sex differences remain unclear, and guidelines for diabetes treatment do not differentiate between sexes. Possible causes for varying outcome include differences in physiology, treatment response, and psychological factors. This review briefly outlines sex differences in hormonal pathophysiology, and thereafter summarizes the literature to date on sex differences in disease course and outcome.

METHODS

Systematic searches were performed on PubMed using "sex", "gender", and various glucose-lowering therapies as keywords. Earlier reviews are summarized and results from individual studies are reported. Reference lists from studies were used to augment the search.

RESULTS

There is an increased risk of missing the diagnosis of T2D when screening women with only fasting plasma glucose instead of with an oral glucose tolerance test. The impact of various risk factors for complications may differ by sex. Efficacy and side effects of some glucose-lowering drugs differ between men and women. Men with T2D appear to suffer more microvascular complications, while women have higher morbidity and mortality in cardiovascular disease and also fare worse psychologically.

CONCLUSION

Few studies to date have focused on sex differences in T2D. Several questions demand further study, such as whether risk factors and treatment guidelines should be sex-specific. There is a need for clinical trials designed specifically to evaluate sex differences in efficacy and outcome of the available treatments.

Sex differences in diabetes and risk of incident coronary artery disease in healthy young and middle-aged adults

OBJECTIVE

Controversy exists about the coronary artery disease (CAD) risk conveyed by diabetes in young and middle-aged women. We investigated sex differences in CAD by diabetes status among healthy individuals with different underlying risks of heart disease.

RESEARCH DESIGN AND METHODS

We examined subjects aged <60 years without CAD at enrollment in the high-risk GeneSTAR Study (n = 1,448; follow-up ∼12 years), Multi-Ethnic Study of Atherosclerosis (MESA; n = 3,072; follow-up ∼7 years), and National Health and Nutrition Examination Survey III (NHANES III) Mortality Follow-up Study (n = 6,997; follow-up ∼15 years). Diabetes was defined by report, hypoglycemic use, and/or fasting glucose ≥126 mg/dL. The outcome was any CAD event during follow-up (fatal CAD in NHANES).

RESULTS

In the absence of diabetes, CAD rates were lower among women in GeneSTAR, MESA, and NHANES (4.27, 1.66, and 0.40/1,000 person-years, respectively) versus men (11.22, 5.64, and 0.88/1,000 person-years); log-rank P < 0.001 (GeneSTAR/MESA) and P = 0.07 (NHANES). In the presence of diabetes, CAD event rates were similar among women (17.65, 7.34, and 2.37/1,000 person-years) versus men (12.86, 9.71, and 1.83/1,000 person-years); all log-rank P values > 0.05. Adjusting for demographics, diabetes was associated with a significant four- to fivefold higher CAD rate among women in each cohort, without differences in men. In meta-analyses of three cohorts, additionally adjusted for BMI, smoking, hypertension, HDL, and non-HDL cholesterol, antihypertensive and cholesterol-lowering medication use, the hazard ratio of CAD in men versus women among nondiabetes was 2.43 (1.76-3.35) and diabetes was 0.89 (0.43-1.83); P = 0.013 interaction by diabetes status.

CONCLUSIONS

Though young and middle-aged women are less likely to develop CAD in the absence of diabetes, the presence of diabetes equalizes the risk by sex. Our findings support aggressive CAD prevention strategies in women with diabetes and at similar levels to those that exist in men.

The association between socioeconomic status and cardiovascular risk factors among middle-aged and older men and women

Studies of gender differences in the association between socioeconomic status (SES) and cardiovascular risk factors have produced mixed findings. The purpose of this research was to examine whether the association between SES and cardiovascular risk factors differed between older men and women. Using data on physical measures and biomarkers from the 2006 Health and Retirement Study (N = 2,502 men; N = 3,474 women), linear regression models were used to estimate the association between SES and seven cardiovascular risk factors. Interactions between gender and SES were tested. For all seven risks assessed, we observed significant associations of selected SES factors to cardiovascular risk for men and/or women. In all of these cases, lower SES was associated with higher cardiovascular risk. However, for six of the factors, we also observed gender differences in the association between SES and cardiovascular risk, such that lower SES was associated with higher cardiovascular risk for women but not for men. These findings suggest that the association between SES and cardiovascular risk is more pronounced for women than for men. Implementing interventions to reduce cardiovascular risk factors, particularly among older women with lower SES, might, over time, reduce cardiovascular disease in women and improve quality of life.

Gender differences in fat distribution and inflammatory markers among Arabs

Recent studies from the Gulf region suggest that compared to men, women have a greater risk of developing metabolic syndrome (MeS). Objective. To investigate gender differences in body composition, adipokines, inflammatory markers, and aerobic fitness in a cohort of healthy Qatari adults. Participants. Healthy Qatari (n = 58) were matched for age, gender, and body mass index. Methods. Body composition and regional fat distribution were determined by dual-energy X-ray absorptiometry and computerized tomography. Laboratory assessments included serum levels of fasting glucose, insulin, lipid profile analysis, adipokines, and inflammatory markers. Subjects were also evaluated for aerobic fitness. Results. Women had more adipose tissue in the total abdominal (P = 0.04) and abdominal subcutaneous (P = 0.07) regions compared to men. Waist circumference and indices of insulin sensitivity were similar; however, women had a more favourable lipid profile than men. Serum adiponectin and leptin levels were significantly higher in women, whereas inflammatory profiles were not different between men and women. Aerobic fitness was lower in women and was associated with abdominal fat accumulation. Conclusion. In premenopausal women, higher levels of adiponectin may support maintenance of insulin sensitivity and normolipidemia despite greater adiposity. However, poor aerobic fitness combined with abdominal fat accumulation may explain their greater future risk of MeS compared with men.

Ovariectomy reinstates the infarct size-limiting effect of postconditioning in female rabbits

Gender seems to interfere with the cardioprotective effect of ischemic preconditioning (PreC) and postconditioning (PostC); PreC-conferred protection is weaker or lost in female animals after ovariectomy (Ov), while the role of PostC is still in dispute. We sought to investigate the effect of PostC in female rabbits, its interaction with Ov, and the potential implicated intracellular pathways. Intact or Ov adult female rabbits (n = 46) were subjected to 30 min ischemia and reperfusion with PostC (PostC or OvPostC), which consisted of six cycles of 30-s ischemia/30-s reperfusion at the end of ischemia, or without PostC (Fem or OvFem). Infarct size (I) and area at risk (R) were determined by TTC staining and fluorescent particles, respectively, after 3-h reperfusion in 30 out of 46 animals. Plasma levels of estradiol and nitrite/nitrate (NO x ) were evaluated. ERKs, p38-MAPK, and Akt assessment was performed in excised hearts 1-min after starting the final reperfusion period in the remaining 16 animals. Infarct size was significantly reduced only in OvPostC group (I/R ratio, 25.3 ± 2.7, vs 48.1 ± 2.0, 43.6 ± 4.2 and 55.1 ± 5.6 % in Fem, OvFem, and PostC groups, p < 0.05). In ovariectomized rabbits, plasma estradiol and NO x levels were lower than in the normal ones. Akt phosphorylation in ischemic regions was significantly higher in OvPostC group, whereas ERK1/2 and p38-MAPK activation was observed in all ovariectomized animals irrespective of PostC. PostC is not effective in female rabbits, but the protection is reinstated after Ov potentially via the RISK pathway.

Vascular brain lesions, brain atrophy, and cognitive decline. The Second Manifestations of ARTerial disease--Magnetic Resonance (SMART-MR) study

We examined the association between brain atrophy and vascular brain lesions (i.e., white matter lesions [WMLs] or brain infarcts), alone or in combination, with decline in memory and executive functioning over 4 years of follow-up in 448 patients (57 ± 9.5 years) with symptomatic atherosclerotic disease from the Second Manifestations of ARTerial disease--Magnetic Resonance SMART-MR study. Automated brain segmentation was used to quantify volumes of total brain, ventricles, cortical gray matter, and WMLs on 1.5-T magnetic resonance imaging (MRI). Brain infarcts were rated visually. WML volume was associated with significant decline in z score of executive functioning. No independent associations between MRI measures and memory decline were found. Significant declines in z scores of memory performance and of executive functioning were observed in patients with a combination of severe atrophy (upper quartile) and most vascular brain lesions (upper quartile) compared with those with minimal atrophy (lowest quartile) and fewest vascular brain lesions (lowest quartile). Our findings suggest that in patients with symptomatic atherosclerotic disease, the combination of brain atrophy and WMLs or brain infarcts accelerates cognitive decline over 4 years.

Impact of age and sex on response to ischemic preconditioning in the rat heart: differential role of the PI3K–AKT pathway

Sex and aging represent important factors that determine morbidity and mortality due to cardiovascular diseases in the human population. This study aimed to investigate the impact of aging on the response to ischemia–reperfusion in male and female rat hearts, and to explore a potential role of the PI3K–Akt pathway in the cardioprotective effects of ischemic preconditioning (IPC) in the myocardium of younger and older adult males and females. Langendorff-perfused nonpreconditioned and preconditioned hearts of 12- and 18-week-old male and female Wistar rats were subjected to regional ischemia and reperfusion with or without prior perfusion with the PI3K inhibitor wortmannin for the evaluation of ischemia-induced arrhythmias and the size of myocardial infarction (infarct size; IS). Aging did not modify IS in both sexes; however, it markedly increased susceptibility to arrhythmias. Although IPC effectively reduced IS in males and females of both ages, only the hearts of males and 18-week-old females benefited from its antiarrhythmic effect. In the preconditioned 12-week-old females, but not the 18-week-old females, and in males of both ages, wortmannin blunted the anti-infarct effect of IPC. In conclusion, activation of the PI3K–Akt pathway plays an important role in protection against lethal injury conferred by IPC in males irrespective of age. The IS-limiting effect of IPC appears to be PI3K–Akt-dependent only in the 12-week-old females.

Gender differences and disparities in all-cause and coronary heart disease mortality: epidemiological aspects

This overview is primarily concerned with large recent prospective cohort studies of adult populations, not patients, because the latter studies are confounded by differences in medical and surgical management for men vs. women. When early papers are uniquely informative they are also included. Because the focus is on epidemiology, details of age, sex, sample size, and source as well as study methods are provided. Usually the primary outcomes were all-cause or coronary heart disease (CHD) mortality using baseline data from midlife or older adults. Fifty years ago few prospective cohort studies of all-cause or CHD mortality included women. Most epidemiologic studies that included community-dwelling adults did not include both sexes and still do not report men and women separately. Few studies consider both sex (biology) and gender (behavior and environment) differences. Lifespan studies describing survival after live birth are not considered here. The important effects of prenatal and early childhood biologic and behavioral factors on adult mortality are beyond the scope of this review. Clinical trials are not discussed. Overall, presumptive evidence for causality was equivalent for psychosocial and biological exposures, and these attributes were often associated with each other. Inconsistencies or gaps were particularly obvious for studies of sex or gender differences in age and optimal measures of body size for CHD outcomes, and in the striking interface of diabetes and people with the metabolic syndrome, most of whom have unrecognized diabetes.

Eating rate is associated with cardiometabolic risk factors in Korean adults

BACKGROUND AND AIM

Eating slowly is a crucial concept in behavioural nutrition and is recommended for weight management as it is believed to have an important effect on satiety control. This study aimed to determine whether or not eating rate is associated with cardiometabolic risk factors.

METHODS AND RESULTS

This was a cross-sectional study involving 8775 Korean adults, who visited the Center for Health Promotion of Korea University Anam Hospital in Seoul, Korea. In male study participants, weight and body mass index (BMI) were found to depend on eating rate after adjusting for age, alcohol consumption, smoking, exercise and total energy intake. When adjusted for age, alcohol consumption, smoking, exercise and BMI, differences were found between the eating rate groups with respect to high-density lipoprotein (HDL)-cholesterol, alanine aminotransferase (ALT) and alkaline phosphatase (ALP) values, white blood cell (WBC) count and total energy intake. Female participants were found to be different from males in that diastolic blood pressure and low-density lipoprotein (LDL)- and HDL-cholesterol values were significantly different between each eating rate group, while ALT and ALP values, WBC count and total energy intake were not. Compared with the slow eating rate group (>15 min), the fastest eating rate group (<5 min) had significantly increased odds ratios for cardiometabolic risk factors such as high glucose and low HDL-cholesterol levels in males, even after adjusting for BMI.

CONCLUSION

Fast eating rates are associated with obesity and other cardiometabolic risk factors, particularly in men. Thus, eating slowly is recommended for weight reduction and to decrease cardiovascular risk factors.

Gender differences in the clinical characteristics of Saudi heart failure patients with subsequent stroke

BACKGROUND AND OBJECTIVES

Studies about stroke in Saudi Arabia are limited. This retrospective study aims to determine the clinical characteristics of Saudi patients with heart failure (HF) with and without subsequent stroke, and also to find out whether gender differences exist in the presentation of HF patients who had stroke.

DESIGN AND SETTINGS

Retrospective study done at King Abdulaziz Medical City (KAMC), Riyadh, Saudi Arabia, from 2002-2008.

PATIENTS AND METHODS

A total of 293 patient (151 males, 142 females) charts from 2002-2008 were re.viewed at KAMC. These charts were from Saudi patients who were diagnosed with HF, with and without subsequent stroke. Demographics, HF characteristics, stroke risk factors, and metabolic characteristics were noted and analyzed.

RESULTS

No difference was observed in HF characteristics and stroke risk factors among HF patients with and without subsequent stroke. In terms of metabolic profile, those who had stroke had significantly higher low-density lipoprotein (LDL)--cholesterol levels as compared to those without (P=.03). Stratification to gender and adjusting for age and risk factors revealed that significantly higher LDL-cholesterol and total cholesterol levels were observed in female stroke patients (P values .02, .028, respectively) and significantly higher blood urea nitrogen levels were observed in male stroke patients (P=.04) as compared to their counterparts who never had a stroke.

CONCLUSION

The gender differences in the metabolic presentation of Saudi HF patients with stroke warrant further clinical investigation. Atherogenic dyslipidemia and renal insufficiency are suggested to be early predic.tors for stroke and should be closely monitored in Saudi HF patients.

Apoptosis and autophagy contribute to gender difference in cardiac ischemia-reperfusion induced injury in rats

AIMS

Gender difference in cardiac ischemia-reperfusion (IR) induced injury has been reported in animal models. However, a large-scale clinical trial found an increase in cardiovascular incidents in women with hormone replacement therapy. The present study is aimed to explore possible mechanisms of gender difference in cardiac IR induced injury.

MAIN METHODS

Male and female Sprague-Dawley rats were subjected to a 30-min coronary arterial occlusion followed by reperfusion. The infarct size and apoptotic cell number at 24h after reperfusion were significantly lower in female rats than in male rats.

KEY FINDINGS

Male rats expressed higher anti-apoptotic protein Bcl2 levels compared with female rats under physiological conditions. However, levels of Bcl2 were reduced significantly after IR in male rats but not in, female rats. Levels of pro-apoptotic protein, Bax and phospho-p38, showed similar under physiological conditions. In response to IR expression of Bax was markedly reduced in female rats but not in male rats, and expression of phospho-p38 was significantly increased in male rats but not in female rats. In addition, female rats showed marked increase of autophagy marker, ratio of LC3B to LC3A, while male rats significantly decreased the ratio in response to IR.

SIGNIFICANCE

Gender difference in IR injury is due to the different regulation of anti-apoptotic protein, pro-apoptotic protein and autophagy protein levels in male rats and levels in female rats. Our results provide better understanding of sex differences in cardiac IR injury.

Systemic vascular hemodynamic changes due to 17-β-estradiol intranasal administration

PURPOSE

According to the literature, estradiol has a direct vasodilator action by means of endothelium-derived relaxing factor synthesis. The present study aims to evaluate the acute hemodynamic effects of intranasal 17-β-estradiol on cerebral and lower limb arterial circulation in postmenopausal women.

METHODS

Sixteen healthy women in natural menopause (mean age: 54 ± 3 years) were investigated for at least 6 months, each receiving 300 µg of intranasal 17-β-estradiol. We evaluated the heart rate, systolic/diastolic blood pressure, peak systolic velocity, end-diastolic velocity, and velocity-time integral (VTI) at the level of internal carotid and posterior tibial arteries, before and after 30, 60, and 180 minutes of drug administration.

RESULTS

After intranasal 17-β-estradiol administration, the internal carotid artery VTI showed statistically significant (P < .05) variations at all the time intervals after administration of the drug (30, 60, and 180 minutes) when compared with "time zero" (T0, ie, the speed recorded at baseline before drug administration). No significant variation was found at the posterior tibial artery. The systolic/diastolic blood pressure and heart rate did not significantly differ before and after drug administration.

CONCLUSIONS

The administration of a single intranasal dose of 17-β-estradiol in healthy postmenopausal women increased cerebral perfusions, whereas the effect on peripheral circulation was much more limited.

A simple scoring method using cardiometabolic risk measurements in pregnancy to determine 10-year risk of type 2 diabetes in women with gestational diabetes

Objective:

To examine if clustering of cardiometabolic risk factors in pregnancy predicts type 2 diabetes and cardiovascular disease (CVD) risk at 10 years in women with gestational diabetes mellitus (GDM).

Study design and subjects:

A prospective case–control study in 150 GDM and 72 overweight women with normal glucose tolerance (NGT) measured cardiometabolic risk factors (body mass index (BMI), systolic blood pressure (SBP), fasting glucose, insulin, and triglycerides and high-density lipoprotein (HDL) cholesterol) at 28 weeks gestation and 6 months and 10 years after pregnancy. Cluster analysis of cardiometabolic risk factors in pregnancy was used to stratify GDM as ‘high' and ‘low risk' for diabetes and CVD risk at 10 years. The data in pregnancy were used to determine a simple method for assessing risk of future diabetes.

Results:

BMI in the 150 GDM at study entry was similar to NGT, but 35% of GDM fell into a ‘high-risk cluster' with elevated BMI, SBP, glucose, insulin and triglycerides and lower HDL levels. At 10 years, type 2 diabetes was sixfold higher in ‘high-risk' GDM (odds ratio (OR)=6.75, confidence interval (CI)=2.0, 22.7, P=0.002) compared with ‘low-risk' GDM and was not reported in NGT. The ‘high-risk' cluster predicted type 2 diabetes better than BMI>30 (OR=2.13, CI=0.71, 6.4, P=0.179) or fasting glucose >5.5 mmol l^–1, (OR=4.56, CI=1.50, 13.85, P=0.007). We determined that GDM with any four of the cardiometabolic risk factors (BMI>30 kg m^–2, fasting glucose>5.0 mmol l^–1, insulin>7.8 mU l^–1, triglycerides >2.4 mmol l^–1, HDL<1.6 mmol l^–1 or SBP>105 mm Hg) in pregnancy would be in a ‘high-risk' cluster.

Conclusions:

A metabolic syndrome-like cluster in pregnant GDM identifies risk for type 2 diabetes providing an opportunity to focus on rigorous lifestyle interventions after delivery to reduce the burden of disease attributed to this condition.

The Rancho Bernardo Study: 40 years studying why women have less heart disease than men and how diabetes modifies women's usual cardiac protection

Forty years ago, few cohort studies of cardiovascular disease (CVD) included women and fewer still included diabetes or glycemia as a risk factor. I describe here the Rancho Bernardo Study (RBS), a single-site, >40-year cohort study of sex differences in heart disease and how diabetes modifies women's natural cardioprotection. More than 6000 participants were followed for morbidity and mortality, with nearly 3000 survivors (and death certificates for >85% of decedents). In RBS more than half of diabetes was undiagnosed without an oral glucose tolerance test (OGTT); more women than men had isolated post-challenge hyperglycemia (IPH) as their only glucose evidence of diabetes; men had more diabetes than women, with higher fasting but lower post-challenge glucose levels than women; women with diabetes had more classical CVD risk factors than men; excess risk-factor clustering partially explained how diabetes eradicates female cardioprotection. Post-challenge glucose was a stronger CVD risk factor than fasting glucose. Endogenous insulin was not an independent CVD risk factor in women or men. Men with higher testosterone levels developed less diabetes and had fewer metabolic syndrome components. In men higher total testosterone levels predicted a reduced risk of all-cause and CVD but not cancer mortality. In women both extremes of bioavailable testosterone predicted fatal coronary heart disease but not all-cause mortality. Summary point estimates from large systematic reviews of individual data have replicated most RBS findings. Ongoing research can further clarify how diabetes modifies women's cardioprotection from mid-life to old age.

Sex differences in age-related cardiovascular mortality

Introduction

Sex-related physiological differences result in different expressions of diseases for men and women. Data are contradicting regarding the increase in the female risk for cardiovascular disease (CVD) at mid-life. Thus, we studied possible sex differences in age-adjusted mortality for CVD and non-vascular diseases stratifying our findings by specific age groups.

Methods

Over one million deaths (1 080 910) reported to the Finnish nationwide Causes of Death Register in 1986–2009 were analyzed. A total of 247 942 male deaths and 278 752 female deaths were of CVD origin, the remaining deaths were non-vascular. The annual mortality rates were calculated per 100 000 mid-year population, separately for men and women in 5-year age categories.

Results

The age-standardized risk of death from CVD was 80% higher for men (442/100 000) than for women (246/100 000). After age 45–54 the male CVD mortality rate elevated parallel to the non-vascular mortality, whereas in women the CVD mortality elevated considerably more rapidly than the non-vascular mortality from age 60 years onwards.

Conclusions

Heart disease mortality in men accelerates at a relatively young age, but in women the risk shows a steep increase at approximately 60 years of age. These data emphasize the need to identify and prevent risk factors for CVD, especially in women in their mid-life years.

Gender differences in brain susceptibility to oxidative stress are mediated by levels of paraoxonase-2 expression

Paraoxonase 2 (PON2), a member of a gene family that also includes PON1 and PON3, is expressed in most tissues, including the brain. In mouse brain, PON2 levels are highest in dopaminergic areas (e.g., striatum) and are higher in astrocytes than in neurons. PON2 is primarily located in mitochondria and exerts a potent antioxidant effect, protecting mouse CNS cells against oxidative stress. The aim of this study was to characterize PON2 expression and functions in the brains of male and female mice. Levels of PON2 (protein, mRNA, and lactonase activity) were higher in brain regions and cells of female mice. Astrocytes and neurons from male mice were significantly more sensitive (by 3- to 4-fold) to oxidative stress-induced toxicity than the same cells from female mice. Glutathione levels did not differ between genders. Importantly, no significant gender differences in susceptibility to the same oxidants were seen in cells from PON2(-/-) mice. Treatment with estradiol induced a time- and concentration-dependent increase in the levels of PON2 protein and mRNA in male (4.5-fold) and female (1.8-fold) astrocytes, which was dependent on activation of estrogen receptor-α. In ovariectomized mice, PON2 protein and mRNA were decreased to male levels in brain regions and in liver. Estradiol protected astrocytes from wild-type mice against oxidative stress-induced neurotoxicity, but did not protect cells from PON2(-/-) mice. These results suggest that PON2 is a novel major intracellular factor that protects CNS cells against oxidative stress and confers gender-dependent susceptibility to such stress. The lower expression of PON2 in males may have broad ramifications for susceptibility to diseases involving oxidative stress, including neurodegenerative diseases.

Cardiac disease associated with increased risk of nonamnestic cognitive impairment: stronger effect on women

OBJECTIVE

To investigate the association of cardiac disease with amnestic and nonamnestic mild cognitive impairment (aMCI and naMCI, respectively). Nonamnestic mild cognitive impairment, a putative precursor of vascular and other non-Alzheimer dementias, is hypothesized to have a vascular etiology.

DESIGN

A prospective, population-based, cohort study with a median 4.0 years of follow-up.

SETTING

Olmsted County, Minnesota.

PARTICIPANTS

A total of 2719 participants were evaluated at baseline and every 15 months using the Clinical Dementia Rating scale, a neurological evaluation, and neuropsychological testing. A diagnosis of normal cognition, MCI, or dementia was made by consensus. Cardiac disease at baseline was assessed from the participant's medical records.

MAIN OUTCOME MEASURES

Incident MCI, aMCI, or naMCI.

RESULTS

Of 1450 participants without MCI or dementia at baseline, 366 developed MCI. Cardiac disease was associated with an increased risk of naMCI (hazard ratio, 1.77 [95% CI, 1.16-2.72]). However, the association varied by sex (P = .02 for interaction). Cardiac disease was associated with an increased risk of naMCI (hazard ratio, 3.07 [95% CI, 1.58-5.99]) for women but not for men (hazard ratio, 1.16 [95% CI, 0.68-1.99]). Cardiac disease was not associated with any type of MCI or with aMCI.

CONCLUSIONS

Cardiac disease is an independent risk factor for naMCI; within-sex comparisons showed a stronger association for women. Prevention and management of cardiac disease and vascular risk factors may reduce the risk of naMCI.

Prevalence and clinical characteristics of mental stress-induced myocardial ischemia in patients with coronary heart disease

OBJECTIVES

The goal of this study was to evaluate the prevalence and clinical characteristics of mental stress-induced myocardial ischemia.

BACKGROUND

Mental stress-induced myocardial ischemia is prevalent and a risk factor for poor prognosis in patients with coronary heart disease, but past studies mainly studied patients with exercise-induced myocardial ischemia.

METHODS

Eligible patients with clinically stable coronary heart disease, regardless of exercise stress testing status, underwent a battery of 3 mental stress tests followed by a treadmill test. Stress-induced ischemia, assessed by echocardiography and electrocardiography, was defined as: 1) development or worsening of regional wall motion abnormality; 2) left ventricular ejection fraction reduction ≥ 8%; and/or 3) horizontal or downsloping ST-segment depression ≥ 1 mm in 2 or more leads lasting for ≥ 3 consecutive beats during at least 1 mental test or during the exercise test.

RESULTS

Mental stress-induced ischemia occurred in 43.45%, whereas exercise-induced ischemia occurred in 33.79% (p = 0.002) of the study population (N = 310). Women (odds ratio [OR]: 1.88), patients who were not married (OR: 1.99), and patients who lived alone (OR: 2.24) were more likely to have mental stress-induced ischemia (all p < 0.05). Multivariate analysis showed that compared with married men or men living with someone, unmarried men (OR: 2.57) and married women (OR: 3.18), or living alone (male OR: 2.25 and female OR: 2.72, respectively) had higher risk for mental stress-induced ischemia (all p < 0.05).

CONCLUSIONS

Mental stress-induced ischemia is more common than exercise-induced ischemia in patients with clinically stable coronary heart disease. Women, unmarried men, and individuals living alone are at higher risk for mental stress-induced ischemia. (Responses of Myocardial Ischemia to Escitalopram Treatment [REMIT]; NCT00574847).

Age-related differences in cardiac ischemia-reperfusion injury: effects of estrogen deficiency

Despite conflicting evidence for the efficacy of hormone replacement therapy in cardioprotection of postmenopausal women, numerous studies have demonstrated reductions in ischemia/reperfusion (I/R) injury following chronic or acute exogenous estradiol (E2) administration in adult male and female, gonad-intact and gonadectomized animals. It has become clear that ovariectomized adult animals may not accurately represent the combined effects of age and E2 deficiency on reductions in ischemic tolerance seen in the postmenopausal female. E2 is known to regulate the transcription of several cardioprotective genes. Acute, non-genomic E2 signaling can also activate many of the same signaling pathways recruited in cardioprotection. Alterations in cardioprotective gene expression or cardioprotective signal transduction are therefore likely to result within the context of aging and E2 deficiency and may help explain the reduced ischemic tolerance and loss of cardioprotection in the senescent female heart. Quantification of the mitochondrial proteome as it adapts to advancing age and E2 deficiency may also represent a key experimental approach to uncover proteins associated with disruptions in cardiac signaling contributing to age-associated declines in ischemic tolerance. These alterations have important ramifications for understanding the increased morbidity and mortality due to ischemic cardiovascular disease seen in postmenopausal females. Functional perturbations that occur in mitochondrial respiration and Ca(2+) sensitivity with age-associated E2 deficiency may also allow for the identification of alternative therapeutic targets for reducing I/R injury and treatment of the leading cause of death in postmenopausal women.

Distinct endothelial pathways underlie sexual dimorphism in vascular auto-regulation

BACKGROUND AND PURPOSE

Pre-menopausal females have a lower incidence of cardiovascular disease compared with age-matched males, implying differences in the mechanisms and pathways regulating vasoactivity. In small arteries, myogenic tone (constriction in response to raised intraluminal pressure) is a major determinant of vascular resistance. Endothelium-derived dilators, particularly NO, tonically moderate myogenic tone and, because the endothelium is an important target for female sex hormones, we investigated whether NO-mediated moderation of myogenic tone differed between the sexes.

EXPERIMENTAL APPROACH

Pressure-diameter or relaxation concentration-response curves to the NO donor spermine-NO or soluble guanylate cyclase (sGC) stimulation (BAY41-2272) were constructed before and following drug intervention in murine mesenteric resistance arteries. Hypotensive responses to activators of the NO-sGC pathway were determined. Quantitative PCR and Western blotting were used for expression analysis.

KEY RESULTS

NO synthase inhibition enhanced myogenic tone of arteries of both sexes while block of endothelium-derived hyperpolarizing factor (EDHF) enhanced responses in arteries of females only. Spermine-NO concentration-dependently relaxed mesenteric arteries isolated from either sex. However, while inhibition of sGC activity attenuated responses of arteries from male mice only, endothelial denudation attenuated responses of arteries from females only. BAY41-2272 and spermine-NO-induced vasodilatation and hypotension were greater in males than in females.

CONCLUSIONS AND IMPLICATIONS

NO moderated myogenic tone in arteries of male mice by a sGC-dependent pathway while EDHF was the predominant endothelial regulator in arteries of females. This is a potentially important sexual dimorphism in NO-mediated reactivity and further implicates EDHF as the predominant endothelial vasodilator in female resistance arteries.

Sexual dimorphism in rodent models of hypertension and atherosclerosis

Approximately one third of all deaths are attributed to cardiovascular disease (CVD), making it the biggest killer worldwide. Despite a number of therapeutic options available, the burden of CVD morbidity continues to grow indicating the need for continued research to address this unmet need. In this respect, investigation of the mechanisms underlying the protection that premenopausal females enjoy from cardiovascular-related disease and mortality is of interest. In this review, we discuss the essential role that rodent animal models play in enabling this field of research. In particular, we focus our discussion on models of hypertension and atherosclerosis.

Estradiol inhibits vascular endothelial cells pro-inflammatory activation induced by C-reactive protein

In addition of being an important inflammatory biomarker and a risk factor for cardiovascular disease, much evidence indicates that the C-reactive protein (CRP) contributes to the atherosclerosis development process. This plasmatic protein synthesized by hepatocytes in response to inflammation and tissue injury induces pro-inflammatory molecules' expression by endothelial cells (ECs). Previous studies showed that the 17β-estradiol (E2) has beneficial effects on vascular cells by reducing in vitro pro-inflammatory molecules expressions in EC. Therefore, we hypothesize that E2 blocks or reduces CRP-mediated inflammatory responses by modulating endogenous production of CRP in EC and/or activation mechanisms. Using human aortic ECs (HAECs), we first evaluated CRP production by vascular EC and second demonstrated its self-induction. Indeed, recombinant human CRP stimulation induces a fivefold increase of CRP expression. A 1-h pre-treatment of E2 at a physiologic dose (10⁻⁹ M) leads to an important decrease of CRP production suggesting a partial blockage of its amplification loop mechanism. Furthermore, in HAEC, E2 reduces the secretion of the most potent agonist of CRP induction, the IL-6, by 21 %. E2 pre-treatment also decreased the expression of pro-inflammatory molecules IL-8, VCAM-1, and ICAM-1 induced by CRP and involved in leukocytes recruitment. In addition, we demonstrated that E2 could restore vascular endothelial growth factor-mediated EC migration response impaired by CRP suggesting another pro-angiogenic property of this hormone. These findings suggest that E2 can interfere with CRP pro-inflammatory effects via activation signals using its rapid, non-genomic pathway that may provide a new mechanism to improve vascular repair.

Sexual hormones: effects on cardiac and mitochondrial activity after ischemia-reperfusion in adult rats. Gender difference

In this work we studied the influence of sex hormones on heart and mitochondrial functions, from adult castrated female and male, and intact rats. Castration was performed at their third week of life and on the fourth month animals were subjected to heart ischemia and reperfusion. Electrocardiogram and blood pressure recordings were made, cytokines levels were measured, histopathological studies were performed and thiobarbituric acid reactive species were determined. At the mitochondrial level respiratory control, transmembranal potential and calcium management were determined; Western blot of some mitochondrial components was also performed. Alterations in cardiac function were worst in intact males and castrated females as compared with those found in intact females and castrated males, cytokine levels were modulated also by hormonal status. Regarding mitochondria, in those obtained from hearts from castrated females without ischemia-reperfusion, all evaluated parameters were similar to those observed in mitochondria after ischemia-reperfusion. The results show hormonal influences on the heart at functional and mitochondrial levels.

Association between periodontal disease and ischemic heart disease among Swedish women: a cross-sectional study

OBJECTIVE

The aim of this cross-sectional study was to analyze the relationship between chronic periodontitis and ischemic heart disease (IHD).

MATERIAL AND METHODS

A cross-section of women aged 38 to 84 years were examined in 1992-93 (analysis based on n=1056). Medical and dental examinations were included in the analysis specifically with regard to IHD and periodontitis. Other well-known risk factors for IHD were used as covariates in multivariable statistical analysis.

RESULTS

Among the dentate women in this study (n=847), 74 had IHD and 773 did not. There was no statistically significant difference between numbers of pathological gingival pockets between these groups (58.1% had one or more pathological pockets in the IHD group compared to 57.6% in the non-IHD group). Bivariate analysis of dentate individuals showed significant associations between IHD and number of missing teeth, age, body mass index, waist/hip ratio, life satisfaction, hypertension, and levels of cholesterol and triglycerides. However, in the final multivariable logistic regression model, with the exception of age, only number of teeth (<17 teeth) OR = 2.13 (CI 1.20; 3.77) was found to be significantly associated with IHD. Moreover, edentulous women had an OR of 1.94 (CI 1.05; 3.60) in relation to IHD (age-adjusted model).

CONCLUSIONS

In the present study, periodontitis did not seem to have a statistically significant relationship with IHD. The number of missing teeth showed a strong association with IHD, and this may act as a proxy variable tapping an array of different risk factors and behaviors.

Gender differences in association between metabolic syndrome and carotid intima media thickness

Background

Metabolic syndrome (Mets) is a cluster of cardiovascular risk factors which can predicts cardiovascular disease (CVD). Carotid intima-media thickness (CIMT) is known as a surrogate measure of subclinical atherosclerosis and predictor of CVD. Although, it has shown the association between Mets and CIMT, this relation regarding sex differences is limited. We aimed to find out whether gender differences in this association.

Methods

In this cross-sectional study, we recorded height, weight, waist circumference (WC), blood pressure, and lipid profiles. We used Mets; defined based on NCEP ATP III definition, and traditional cardiovascular risk factors; age, body mass index (BMI), WC, hyperlipidemia, and hypertension, in multivariate regression models which including;. The CIMT measurement < 0.73 or ≥0.73 mm was considered as low- or high risk to CVD.

Results

Overall, 150 subjects were enrolled to study that their ages were 36-75 years. The 47.3% of them (71 subjects) had Mets. CIMT was increased in Mets group compared non-Mets group (P = 0.001). In logistic regression analysis, a significant association was found between Mets and CIMT in women, but not in men (p = 0.002, and p = 0.364, respectively). After adjustment to age, WC, BMI, hypertension and hyperlipidemia, this association was significant just in women (p = 0.011) independent of WC, BMI, hyperlipidemia and hypertension.

Conclusion

Our data showed that MetS is a stronger risk factor for subclinical atherosclerosis in women than in men. So, we suggest the assessment of CIMT along with definition Mets in middle-aged women could be lead to earlier detection of at risk individuals to CVD.