Hypertension and cardiovascular disease in women: Progress towards better understanding of gender‐specific differences?

Sex differences and role of lysyl oxidase-like 2 in angiotensin II-induced hypertension in mice

Hypertension, a disease with known sexual dimorphism, accelerates aging-associated arterial stiffening, partly because of the activation of matrix remodeling caused by increased biomechanical load. In this study, we tested the effect of biological sex and the role of the matrix remodeling enzyme lysyl oxidase-like 2 (LOXL2) in hypertension-induced arterial stiffening. Hypertension was induced by angiotensin II (ANG II) infusion via osmotic minipumps in 12- to 14-wk-old male and female mice. Blood pressure and pulse wave velocity (PWV) were measured noninvasively. Wire myography and uniaxial tensile testing were used to test aortic vasoreactivity and mechanical properties. Aortic wall composition was examined by histology and Western blotting. Uniaxial stretch of cultured cells was used to evaluate the effect of biomechanical strain. LOXL2's catalytic function was examined using knockout and inhibition. ANG II infusion-induced hypertension in both genotypes and sexes. Wild-type (WT) males exhibited arterial stiffening in vivo and ex vivo. Aortic remodeling with increased wall thickness, intralamellar distance, higher LOXL2, and collagen I and IV content was noted in WT males. Female mice did not exhibit increased PWV despite the onset of hypertension. LOXL2 depletion improved vascular reactivity and mechanics in hypertensive males. LOXL2 depletion improved aortic mechanics but worsened hypercontractility in females. Hypertensive cyclic strain contributed to LOXL2 upregulation in the cell-derived matrix in vascular smooth muscle cells (VSMCs) but not endothelial cells. LOXL2's catalytic function facilitated VSMC alignment in response to biomechanical strain. In conclusion, in males, arterial stiffening in hypertension is driven both by VSMC response and matrix remodeling. Females are protected from PWV elevation in hypertension. LOXL2 depletion is protective in males with improved mechanical and functional aortic properties. VSMCs are the primary source of LOXL2 in the aorta, and hypertension increases LOXL2 processing and shifts to collagen I accumulation. Overall, LOXL2 depletion offers protection in young hypertensive males and females.NEW & NOTEWORTHY We examined the effect of sex on the evolution of angiotensin II (ANG II)-induced hypertension and the role of lysyl oxidase-like 2 (LOXL2), an enzyme that catalyzes matrix cross linking. While ANG II led to hypertension and worsening vascular reactivity in both sexes, aortic remodeling and stiffening occurred only in males. LOXL2 depletion improved outcomes in males but not females. Thus males and females exhibit a distinct etiology of hypertension and LOXL2 is an effective target in males.

Gender and age disparities in small-to-medium arterial stiffness among the Chinese population

BACKGROUND AND AIMS

Arterial pressure-volume index (API) is a non-invasive tool for assessing small-to-medium-sized arterial stiffness. This study aimed to investigate the potential age- and sex-related differences in the API and explore the practical implications of such differences.

METHODS AND RESULTS

The study analysed 7620 subjects for whom API measurements were available. Linear regression and restrictive cubic spline models were used to investigate the associations between potential risk conditions and the API. Additionally, this study employed a backward stepwise regression method to identify the independent factors associated with a high API. Middle-aged to older women had higher API values and a higher prevalence of high API than men in the same age group. However, the opposite was observed among younger individuals, with women having lower API values than men. This study also identified a J-shaped relationship between API and age, where API values began to increase at a certain age and rapidly increased after that. In women, the API started to increase at 31 years of age and rapidly increased after 54 years of age. In men, the API started to increase at 38 years of age, followed by a rapid increase after 53 years of age.

CONCLUSION

This study's observation of a significant age-sex interaction in small-to-medium-sized arterial stiffening offers a valuable explanation for cardiovascular disease risk and provides important parameters for using API measurements to evaluate such risk.

Sex moderations in the relationship between aortic stiffness, cognition, and cerebrovascular reactivity in healthy older adults

It is well established that sex differences exist in the manifestation of vascular diseases. Arterial stiffness (AS) has been associated with changes in cerebrovascular reactivity (CVR) and cognitive decline in aging. Specifically, older adults with increased AS show a decline on executive function (EF) tasks. Interestingly, the relationship between AS and CVR is more complex, where some studies show decreased CVR with increased AS, and others demonstrate preserved CVR despite higher AS. Here, we investigated the possible role of sex on these hemodynamic relationships. Acquisitions were completed in 48 older adults. Pseudo-continuous arterial spin labeling (pCASL) data were collected during a hypercapnia challenge. Aortic pulse wave velocity (PWV) data was acquired using cine phase contrast velocity series. Cognitive function was assessed with a comprehensive neuropsychological battery, and a composite score for EF was calculated using four cognitive tests from the neuropsychological battery. A moderation model test revealed that sex moderated the relationship between PWV and CVR and PWV and EF, but not between CVR and EF. Together, our results indicate that the relationships between central stiffness, cerebral hemodynamics and cognition are in part mediated by sex.

Time trends in the relation between blood pressure and dementia in 85-year-olds

OBJECTIVES

Blood pressure has decreased in the general population. We aimed to examine whether this is true also among the very old, and among persons with and without dementia. Further, we aimed to investigate how common undetected and untreated hypertension is in the very old, both among people with and without dementia.

METHOD

Blood pressure was measured in representative population samples of 85-year-olds living in Gothenburg, Sweden, examined 1986-1987 (n = 484) and 2008-2010 (n = 571). Dementia was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, edition 3 revised, by the same medical doctor at both examinations.

RESULTS

Both systolic and diastolic blood pressure were lower in 85-year-olds examined 2008-2010 than in those examined 1986-1987, both among those with and without dementia. Participants with dementia had lower systolic blood pressure than those without dementia in both cohorts, and blood pressure levels related to dementia severity. Despite this, hypertension (≥140/90 mmHg) was found in almost half (46.5%) of those with dementia in 2008-2010.

CONCLUSION

Our findings show that time-trends of lower blood pressure in western populations also applies to the very old, and that individuals with dementia continue to have lower blood pressure compared to the rest of the population. The latter finding suggests that the pathophysiological processes in dementia affect blood pressure regulating regions in the brain independent of time trends. Still, hypertension is common in dementia and needs to be detected and treated.

Sex differences in mechanisms of arterial stiffness

Arterial stiffness progressively increases with aging and is an independent predictor of cardiovascular disease (CVD) risk. Evidence supports that there are sex differences in the time course of aging-related arterial stiffness and the associated CVD risk, which increases disproportionately in postmenopausal women. The association between arterial stiffness and mortality is almost twofold higher in women versus men. The differential clinical characteristics of the development of arterial stiffness between men and women indicate the involvement of sex-specific mechanisms. This review summarizes the current literature on sex differences in vascular stiffness induced by aging, obesity, hypertension, and sex-specific risk factors as well as the impact of hormonal status, diet, and exercise on vascular stiffness in males and females. An understanding of the mechanisms driving sex differences in vascular stiffness has the potential to identify novel sex-specific therapies to lessen CVD risk, the leading cause of death in males and females. LINKED ARTICLES: This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.

Sex differences in time trends of blood pressure among Swedish septuagenarians examined three decades apart: a longitudinal population study

OBJECTIVE

The aim of this study was to analyze the influence of birth cohort, sex and age on the trajectories of SBP and DBP in two birth cohorts of 70-year-olds, examined 3 decades apart and followed up at ages 75 and 79-80 years.

METHODS

Two population samples of 70-year-olds from Gothenburg, Sweden, were examined. The first, born in 1901-1902, was examined in 1971-1972 (n = 973). The second, born in 1930, was examined in 2000 (n = 509). Both samples were re-examined at ages 75 and 79-80 years.

RESULTS

We found that SBP and DBP were considerably lower in septuagenarian men and women born 1930 compared with those born 1901-1902, also when adjusting for antihypertensive treatment in different ways. The decline was especially pronounced in women. Blood pressure was higher in women than in men in the 1970s, whereas there were no sex differences in the 2000s. The age-related decline in SBP started earlier and was more accentuated in those born in 1930 than in those born in 1901-1902.

CONCLUSION

Blood pressure decreased, and the age-related decline in SBP started earlier in septuagenarians examined in the 2000s compared with those examined in the 1970s. The decrease was especially pronounced in women and diminished the sex differences. Antihypertensive treatment only partly explained our findings, suggesting that other mostly unknown factors played an important role.

Latent class analysis suggests four classes of persons with type 2 diabetes mellitus based on complications and comorbidities in Tianjin, China: a cross-sectional analysis

The aim of this study was to explore a new classification way in persons with type 2 diabetes mellitus based on complications and comorbidities using Latent Class Analysis, moreover, finding out the factors associated with different latent classes and making specific suggestions. In this study, 5,500 patients with type 2 diabetes mellitus from ten hospitals in Tianjin, China were selected, and the response rate was 96.2%. Latent Class Analysis was used to cluster patients. After compared the baseline characteristics, multinomial logistic regression was applied. Patients with type 2 diabetes mellitus were classified into four classes. In the univariate analysis, all variables were significant (p<0.05). According to multinomial logistic regression, we found longer duration of type 2 diabetes mellitus, family history of diabetes, older age, obesity and central obesity, female menopause, living in a suburb, having a higher 2hPG at diagnosis, smoking and drinking were associated with the prevalence of complications and comorbidities. In conclusion, LCA was shown to be an effective method for grouping patients with T2DM, which presented a nuanced approach to data reduction. Further research using LCA may be especially useful to investigate causal relationships between complications and the significant factors identified in our study.

The association between pulse wave velocity and cognitive function: the Sydney Memory and Ageing Study

OBJECTIVES

Pulse wave velocity (PWV) is a measure of arterial stiffness and its increase with ageing has been associated with damage to cerebral microvessels and cognitive impairment. This study examined the relationship between carotid-femoral PWV and specific domains of cognitive function in a non-demented elderly sample.

METHOD

Data were drawn from the Sydney Memory and Ageing Study, a cohort study of non-demented community-dwelling individuals aged 70-90 years, assessed in successive waves two years apart. In Wave 2, PWV and cognitive function were measured in 319 participants. Linear regression was used to analyse the cross-sectional relationship between arterial stiffness and cognitive function in the whole sample, and separately for men and women. Analysis of covariance was used to assess potential differences in cognition between subjects with PWV measurements in the top and bottom tertiles of the cohort. Covariates were age, education, body mass index, pulse rate, systolic blood pressure, cholesterol, depression, alcohol, smoking, hormone replacement therapy, apolipoprotein E ε4 genotype, use of anti-hypertensive medications, history of stroke, transient ischemic attack, myocardial infarction, angina, diabetes, and also sex for the whole sample analyses.

RESULTS

There was no association between PWV and cognition after Bonferroni correction for multiple testing. When examining this association for males and females separately, an association was found in males, with higher PWV being associated with lower global cognition and memory, however, a significant difference between PWV and cognition between males and females was not found.

CONCLUSION

A higher level of PWV was not associated with lower cognitive function in the whole sample.

Cardiovascular disease in women

Gender-specific data focused on cardiovascular disease (CVD) are becoming increasingly available. This is of great importance, given that CVD has become the number 1 killer of women, and unlike for men, mortality rates do not seem to be declining. Many factors are cited as the causes of sex-based differences, including delays in recognizing symptoms, underutilization of diagnostic tests and treatments, as well as anatomic, physiological, and genetic factors. Evidence of fundamental biological differences in vascular function and the underlying pathologic processes is only beginning to elucidated, motivated by growing evidence of differences in clinical presentations and outcomes between men and women. The good news is that we are starting to see improvements in outcomes for women, such as after coronary revascularization; decrease in complication rates with the advent of new techniques, such as radial access for cardiac catheterizations; as well as increased participation of women in clinical trials. The underlying mechanisms of ischemic heart disease remain to be elucidated, and will help guide therapy and ultimately may explain the higher prevalence of : subendocardial myocardial infarctions, spontaneous arterial dissections, plaque erosion, increased vasospastic disorders, such as coronary microvascular disease, and pulmonary hypertension in women compared with men. We have made great progress in understanding gender-related differences in CVDs, but much remains to be done to optimize the prevention of CVD for both men and women.

Prevalence of hypertension and pre-hypertension in rural women: a report from the villages of West Bengal, a state in the eastern part of India

OBJECTIVE

To find out the prevalence of hypertension, pre-hypertension and tachycardia among the women in rural areas of West Bengal, identify co-factors associated with the prevalence and contribute to the body of evidence for future health programs to identify at-risk groups.

DESIGN

A population-based cross-sectional study was conducted.

SETTING

The study was conducted in remote villages.

PARTICIPANTS

1186 women participants, aged 18 years or more were included.

MAIN OUTCOME MEASURES

They were interviewed using standard structured questionnaire. Blood pressure and tachycardia was monitored using digital sphygmomanometer. For each participant, we made two blood pressure measurements with an interval of 48 hours. Data was analysed statistically using SPSS software.

RESULTS

Overall prevalence of hypertension in the study subjects was 24.7% and that of pre-hypertension and tachycardia was 40.8% and 6.4%, respectively. Both hypertension and pre-hypertension were seen to increase with age. Other identified significant factors were use of biomass fuel for cooking, absence of separate kitchen, higher body mass index (BMI), education and average family income.

CONCLUSION

This study suggests quite high prevalence of hypertension as well as pre-hypertension among the women of rural areas. The findings are significant from the women health perspectives. Early detection of pre-hypertensive and hypertensive subjects will help to formulate intervention strategies to allay the spread of cardiovascular diseases.

Gender differences in artery wall biomechanical properties throughout life

Elevated large artery stiffness and pulse pressure have emerged as important risk factors for cardiovascular disease. The genders differ in large artery biomechanical properties throughout the lifespan with females displaying higher stiffness than males during the prepubertal years and a dramatic increase after menopause. Males on the other hand experience an increase in arterial stiffness postpuberty and a linear increase thereafter, suggesting that females have intrinsically stiffer large arteries than males, but that such effects are mitigated by sex steroids during the reproductive years. This review discusses anthropometric and sex steroid influences on gender differences in large artery stiffness and pressure dynamics from childhood to senescence. In particular, the sex-specific effects of estrogen, progesterone and testosterone on vascular structure and function and how these influence arterial stiffness are explored. These factors may contribute in part to the observed gender differences in the pathophysiology and clinical manifestations of cardiovascular disease.

Hearing sensitivity in older adults: associations with cardiovascular risk factors in the health, aging and body composition study

OBJECTIVES

To examine the association between cardiovascular disease (CVD) and its risk factors and age-associated hearing loss in a cohort of older black and white adults.

DESIGN

Cross-sectional cohort study.

SETTING

The Health, Aging, and Body Composition (Health ABC) Study, a community-based cohort study of older adults from Pittsburgh, Pennsylvania, and Memphis, Tennessee.

PARTICIPANTS

Two thousand forty-nine well-functioning adults (mean age 77.5; 37% black).

MEASUREMENTS

Pure-tone audiometry measurement and history of clinical CVD were obtained at the fourth annual follow-up visit. Pure-tone averages in decibels reflecting low (250, 500, and 1,000 Hz), middle (500, 1,000, and 2,000 Hz), and high (2,000, 4,000, and 8,000 Hz) frequencies were calculated for each ear. CVD risk factors, aortic pulse-wave velocity (PWV), and ankle-arm index (AAI) were obtained at study baseline.

RESULTS

In sex-stratified models, after adjustment for age, race, study site, and occupational noise exposure, risk factors associated with poorer hearing sensitivity in men included high triglyceride levels, high resting heart rate, and history of smoking. In women, poor hearing sensitivity was associated with high body mass index, high resting heart rate, fast PWV, and low AAI.

CONCLUSION

Modifiable risk factors for CVD may play a role in the development of age-related hearing loss.

Influences of gender on the interaction between sympathetic nerve traffic and central adiposity

CONTEXT

Sympathetic activation promotes insulin resistance and arterial hypertension with increasing adiposity. A difference in the relationship between adiposity and sympathetic activity between women and men could contribute to the known gender difference in cardiovascular disease risk.

OBJECTIVE

We tested whether muscle sympathetic nerve activity (MSNA) is correlated differently with waist circumference, waist to hip ratio (WHR), and body mass index (BMI) in women and men.

DESIGN AND SETTING

We pooled data from two microneurography centers (Berlin, Germany; Gdansk, Poland) for a cross-sectional study.

PARTICIPANTS

We studied 111 normotensive, healthy Caucasian subjects (70 males and 41 females). Age ranged between 19 and 62 yr and BMI ranged between 18 and 40 kg/m(2).

INTERVENTION

No intervention was applied during the study.

MEASUREMENTS

Supine heart rate, blood pressure, and MSNA were recorded after at least 30 min rest.

RESULTS

MSNA in bursts per minute was age dependent in both sexes [r (male) = 0.56, r (female) = 0.34, P < 0.01]. Controlling for waist and hip circumferences, age dependence remained highly significant in men (r = 0.43) and women (r = 0.43). Adjusting for age, in men, waist circumference (r = 0.29), WHR (r = 0.39), and BMI (r = 0.31) were predictive for MSNA and directly correlated (P < 0.01) but not in women. Adjusting for BMI, in men, only WHR (r = 0.40) remained predictive for MSNA.

CONCLUSION

These data support the hypothesis of a gender difference in the regulation of the sympathetic nervous system, in which MSNA mainly relates to WHR in men but not women. The phenomenon may contribute to the sexual dimorphism in cardiovascular disease risk.

Sex differences in blood pressure response to antihypertensive therapy in Chinese patients with hypertension

BACKGROUND

Sex-specific responses to antihypertensive drugs are not very well understood.

OBJECTIVE

To investigate sex-related differences in blood pressure response to antihypertensive drugs in a community-based prospective clinical trial.

METHODS

We recruited 3535 untreated hypertensive patients (2326 women), aged 40-75 years, from 7 rural communities in China. Subjects were randomized to 1 of 4 drug groups: atenolol, hydrochlorothiazide (HCTZ), captopril, or sustained-released nifedipine; duration of the study was 8 weeks. Mean blood pressure reduction, blood pressure control rates, and frequency of adverse events were compared between men and women.

RESULTS

Women had a better response to HCTZ in relation to diastolic blood pressure (1.8 mm Hg lower) than did men (p < 0.05) and were 57% more likely to reach the control goal of diastolic blood pressure than were men (p < 0.05). In the atenolol group, mean systolic blood pressure decreased 3.9 mm Hg more in women than in men (p < 0.05), and women were 65% more likely to reach the control goal of systolic blood pressure and 57% more likely to reach the control goal of diastolic blood pressure than were men (p < 0.05). Significant sex-related differences were also found in drug-related adverse events in the nifedipine group (15.8% in women vs 9.8% in men; p = 0.017) and in the captopril group (14.3% in women vs 8.4% in men; p = 0.005), but no differences were seen with HCTZ or atenolol.

CONCLUSIONS

Women have better blood pressure responses to HCTZ and atenolol and experience more adverse effects with sustained-release nifedipine and captopril than do men, indicating that sex should be taken into account when selecting antihypertensive drugs.