Sex differences in predictors of longitudinal changes in carotid artery stiffness: the Multi-Ethnic Study of Atherosclerosis

Sex differences in the association between stroke risk factors and pre-clinical predictors of stroke in the childhood determinants of Adult Health study

BACKGROUND AND AIMS

It is unclear why blood pressure (BP), metabolic markers and smoking increase stroke incidence in women more than men. We examined these associations with carotid artery structure and function in a prospective cohort study.

METHODS

Participants in the Australian Childhood Determinants of Adult Health study at ages 26-36 years (2004-06) were followed-up at 39-49 years (2014-19). Baseline risk factors included smoking, fasting glucose, insulin, systolic and diastolic BP. Carotid artery plaques, intima-media thickness [IMT], lumen diameter and carotid distensibility [CD] were assessed at follow up. Log binomial and linear regression with risk factor × sex interactions predicted carotid measures. Sex-stratified models adjusting for confounders were fitted when significant interactions were identified.

RESULTS

Among 779 participants (50% women), there were significant risk factor × sex interactions with baseline smoking, systolic BP and glucose associated with carotid measures in women only. Current smoking was associated with incidence of plaques (RRunadjusted 1.97 95% CI 1.4, 3.39), which reduced when adjusted for sociodemographics, depression, and diet (RRadjusted 1.82 95% CI 0.90, 3.66). Greater systolic BP was associated with lower CD adjusted for sociodemographics (βadjusted -0.166 95% CI -0.233, -0.098) and hypertension with greater lumen diameter (βunadjusted 0.131 95% CI 0.037, 0.225), which decreased when adjusted for sociodemographics, body composition and insulin (βadjusted 0.063 95% CI -0.052, 0.178). Greater glucose (βunadjusted -0.212 95% CI -0.397, -0.028) was associated with lower CD, which decreased when adjusted for sociodemographics, BP, depression and polycystic ovary syndrome (βadjusted -0.023 95% CI -0.249, 0.201).

CONCLUSIONS

Smoking, SBP and glucose affect carotid structure and function more in women than men with some of this risk due to co-occurring risk factors.

Central and local arterial stiffness in White Europeans compared to age-, sex-, and BMI-matched South Asians

BACKGROUND

Ethnicity impacts cardiovascular disease (CVD) risk, and South Asians demonstrate a higher risk than White Europeans. Arterial stiffness is known to contribute to CVD, and differences in arterial stiffness between ethnicities could explain the disparity in CVD risk. We compared central and local arterial stiffness between White Europeans and South Asians and investigated which factors are associated with arterial stiffness.

METHODS

Data were collected from cohorts of White Europeans (the Netherlands) and South Asians (India). We matched cohorts on individual level using age, sex, and body mass index (BMI). Arterial stiffness was measured with ARTSENS® Plus. Central stiffness was expressed as carotid-femoral pulse wave velocity (cf-PWV, m/s), and local carotid stiffness was quantified using the carotid stiffness index (Beta) and pressure-strain elastic modulus (Epsilon, kPa). We compared arterial stiffness between cohorts and used multivariable linear regression to identify factors related to stiffness.

RESULTS

We included n = 121 participants per cohort (age 53±10 years, 55% male, BMI 24 kg/m2). Cf-PWV was lower in White Europeans compared to South Asians (6.8±1.9 vs. 8.2±1.8 m/s, p<0.001), but no differences were found for local stiffness parameters Beta (5.4±2.4 vs. 5.8±2.3, p = 0.17) and Epsilon (72±35 vs. 70±31 kPa, p = 0.56). Age (standardized β, 95% confidence interval: 0.28, 0.17-0.39), systolic blood pressure (0.32, 0.21-0.43), and South Asian ethnicity (0.46, 0.35-0.57) were associated with cf-PWV; associations were similar between cohorts (p>0.05 for interaction). Systolic blood pressure was associated with carotid stiffness in both cohorts, whereas age was associated to carotid stiffness only in South Asians and BMI only in White Europeans.

CONCLUSION

Ethnicity is associated with central but not local arterial stiffness. Conversely, ethnicity seems to modify associations between CVD risk factors and local but not central arterial stiffness. This suggests that ethnicity interacts with arterial stiffness measures and the association of these measures with CVD risk factors.

Asthma as a Systemic Disease: Cardiovascular Effects Associated with Asthma

Asthma and cardiovascular disease (CVD) pose significant public health burdens. Airway inflammation is central to asthma pathophysiology and systemic inflammation, which occurs in asthma, is central to CVD pathophysiology. Numerous robust epidemiological studies have demonstrated deleterious systemic cardiovascular effects associated with the asthma syndrome. The cardiovascular effects associated with asthma include arterial injury, atherosclerotic CVD events, atrial fibrillation, and hypertension. Asthma is a heterogeneous disease, however, and the risk of CVD is not homogeneous across the various clinical phenotypes and molecular endotypes, highlighting prior inconsistent associations of asthma and its subtypes with various forms of CVD. The mechanistic underpinnings of the increased CVD risk in asthma remain multifactorial and undefined. Collectively, this supports the need for a precision approach in the identification of individuals with asthma who remain at elevated risk of development of cardiovascular diseases to guide both diagnostic and preventive interventions to decrease CVD risk among individuals living with asthma.

Sex-Specific Impacts of Exercise on Cardiovascular Remodeling

Cardiovascular diseases (CVD) remain the leading cause of death in men and women. Biological sex plays a major role in cardiovascular physiology and pathological cardiovascular remodeling. Traditionally, pathological remodeling of cardiovascular system refers to the molecular, cellular, and morphological changes that result from insults, such as myocardial infarction or hypertension. Regular exercise training is known to induce physiological cardiovascular remodeling and beneficial functional adaptation of the cardiovascular apparatus. However, impact of exercise-induced cardiovascular remodeling and functional adaptation varies between males and females. This review aims to compare and contrast sex-specific manifestations of exercise-induced cardiovascular remodeling and functional adaptation. Specifically, we review (1) sex disparities in cardiovascular function, (2) influence of biological sex on exercise-induced cardiovascular remodeling and functional adaptation, and (3) sex-specific impacts of various types, intensities, and durations of exercise training on cardiovascular apparatus. The review highlights both animal and human studies in order to give an all-encompassing view of the exercise-induced sex differences in cardiovascular system and addresses the gaps in knowledge in the field.

Differential effects of dexamethasone on arterial stiffness, myocardial remodeling and blood pressure between normotensive and spontaneously hypertensive rats

Dexamethasone (DEX)-induced hypertension is observed in normotensive rats, but little is known about the effects of DEX on spontaneously hypertensive animals (SHR). This study aimed to evaluate the effects of DEX on hemodynamics, cardiac hypertrophy and arterial stiffness in normotensive and hypertensive rats. Wistar rats and SHR were treated with DEX (50 μg/kg s.c., 14 d) or saline. Pulse wave velocity (PWV), echocardiographic parameters, blood pressure (BP), autonomic modulation and histological analyses of heart and thoracic aorta were performed. SHR had higher BP compared with Wistar, associated with autonomic unbalance to the heart. Echocardiographic changes in SHR (vs. Wistar) were suggestive of cardiac remodeling: higher relative wall thickness (RWT, +28%) and left ventricle mass index (LVMI, +26%) and lower left ventricle systolic diameter (LVSD, -19%) and LV diastolic diameter (LVDD, -10%), with slightly systolic dysfunction and preserved diastolic dysfunction. Also, SHR had lower myocardial capillary density and similar collagen deposition area. PWV was higher in SHR due to higher aortic collagen deposition. DEX-treated Wistar rats presented higher BP (~23%) and autonomic unbalance. DEX did not change cardiac structure in Wistar, but PWV (+21%) and aortic collagen deposition area (+21%) were higher compared with control. On the other side, DEX did not change BP or autonomic balance to the heart in SHR, but reduced RWT and LV collagen deposition area (-12% vs. SHR_CT ). In conclusion, the results suggest a differential effect of dexamethasone on arterial stiffness, myocardial remodeling and blood pressure between normotensive and spontaneously hypertensive rats.

Protocol of Aerobic Exercise and Cognitive Health (REACH): A Pilot Study

A growing body of evidence supports that aerobic exercise can decrease the risk of future cognitive impairment and Alzheimer's disease (AD). There is a pressing need to rigorously determine whether cognitively normal yet at-risk individuals stand to benefit from the protective effects of exercise. The present study will test the feasibility of an aerobic exercise intervention in such a population and inform the design of a larger-scale randomized, controlled trial examining the effect of aerobic exercise on biomarkers of AD in late-middle-aged, at-risk individuals. This was a single-site, 1 : 1 block-randomized, parallel, two-arm trial. Cognitively normal participants aged 45-80 with documentation of familial and genetic AD risk factors were randomly assigned to one of two interventions. The Usual Physical Activity group was provided educational materials about exercise. The Enhanced Physical Activity intervention delivered 26 weeks of individualized and supervised aerobic exercise. Exercise duration and intensity were incrementally increased to 150 min/week and 70-80% of heart rate reserve, respectively. Retention and adherence were measured to assess study feasibility. In addition, pre- and post- intervention differences between the two arms were evaluated for cardiorespiratory fitness, physical activity, brain glucose metabolism, cerebral structure, vascular health, memory, executive function, and mood. Data from randomized controlled trials of exercise training are needed to identify the proper exercise prescription for reducing accumulation of AD biomarkers in cognitively normal individuals. The current trial will contribute to filling that gap while informing the design of large-scale trials.

Carotid artery displacement and cardiovascular disease risk in the Multi-Ethnic Study of Atherosclerosis

Novel technology permits quantification of common carotid artery (CCA) displacement, which is traditionally ignored. We evaluated associations with CCA displacement and cardiovascular disease (CVD) risk and events in a large, multi-ethnic cohort. Right CCA longitudinal displacement (LD), transverse displacement (TD), and grayscale median (GSM) were evaluated using ultrasound speckle-tracking and texture analysis software in 2050 participants. Regression analyses were used to define relationships between CCA LD, TD, GSM, and CVD risk factors. Cox proportional hazards models were used to assess relationships between LD, TD, and incident CVD events. Participants were mean (SD) 64 (10) years old. There were 791 cases with a CVD event over a 12-year median follow-up. The mean LD was 0.29 (0.20) mm. In multivariable models including age, sex, race/ethnicity, heart rate, and CVD risk factors, LD was associated positively with active smoking (β = 0.08, p < 0.001) and inversely with black (β = −0.08, p < 0.001), Chinese (β = −0.05, p < 0.001), and Hispanic (β = −0.04, p < 0.05) race/ethnicities relative to white individuals, heart rate (β = −0.03/10 beats/min, p < 0.001), and diastolic blood pressure (β = −0.01/5 mmHg, p < 0.05). In fully adjusted models, LD and TD were associated with GSM ( p < 0.01), but neither predicted incident CVD events (LD: hazard ratio (HR) 0.77 [0.48 to 1.24], p = 0.3; TD: HR 1.12 [0.8 to 1.57], p = 0.5). CCA LD and TD are associated with race/ethnicity and CVD risk factors but not incident CVD events. LD and TD are not measures of arterial stiffness but their association with GSM suggests that lower LD and TD may be related to structural changes within the carotid arterial wall.

Carotid artery atherosclerosis is associated with mortality in HIV-positive women and men

OBJECTIVE

Among people with HIV, there are few long-term studies of noninvasive ultrasound-based measurements of the carotid artery predicting major health events. We hypothesized that such measurements are associated with 10-year mortality in the Women's Interagency HIV Study (WIHS) and Multicenter AIDS Cohort Study (MACS), and that associations differ by HIV serostatus.

DESIGN

Nested cohort study.

METHODS

Participants without coronary heart disease underwent B-mode carotid artery ultrasound, with measurement of common carotid artery intima-media thickness (IMT); carotid artery plaque (focal IMT > 1.5 mm) at six locations; and Young's modulus of elasticity, a measure of arterial stiffness. We examined all-cause mortality using Cox models, controlling for demographic, behavioral, cardiometabolic, and HIV-related factors.

RESULTS

Among 1722 women (median age 40 years, 90% nonwhite, 71% HIV-positive) and 1304 men (median age 50, 39% nonwhite, 62% HIV-positive), 11% died during follow-up. Mortality was higher among HIV-positive women [19.9 deaths/1000 person-years, 95% confidence interval (CI) 14.7-28.8] than HIV-positive men (15.1/1000, 95% CI 8.3-26.8). In adjusted analyses, plaque was associated with mortality (hazard ratio 1.44, 95% CI 1.10-1.88) regardless of HIV serostatus, and varied by sex (among women, hazard ratio 1.06, 95% CI 0.74-1.52; among men; hazard ratio 2.19, 95% CI 1.41-3.43). The association of plaque with mortality was more pronounced among HIV-negative (hazard ratio 3.87, 95% 1.95-7.66) than HIV-positive participants (hazard ratio 1.35, 95% CI 1.00-1.84). Arterial stiffness was also associated with mortality (hazard ratio 1.43 for highest versus lowest quartile, 95% CI 1.02-2.01). Greater common carotid artery-IMT was not associated with mortality.

CONCLUSION

Carotid artery plaque was predictive of mortality, with differences observed by sex and HIV serostatus.

New insights into arterial stiffening: does sex matter?

This review discusses sexual dimorphism in arterial stiffening, disease pathology interactions, and the influence of sex on mechanisms and pathways. Arterial stiffness predicts cardiovascular mortality independent of blood pressure. Patients with increased arterial stiffness have a 48% higher risk for developing cardiovascular disease. Like other cardiovascular pathologies, arterial stiffness is sexually dimorphic. Young women have lower stiffness than aged-matched men, but this sex difference reverses during normal aging. Estrogen therapy does not attenuate progressive stiffening in postmenopausal women, indicating that currently prescribed drugs do not confer protection. Although remodeling of large arteries is a protective adaptation to higher wall stress, arterial stiffening increases afterload to the left ventricle and transmits higher pulsatile pressure to smaller arteries and target organs. Moreover, an increase in aortic stiffness may precede or exacerbate hypertension, particularly during aging. Additional studies are needed to elucidate the mechanisms by which females are protected from arterial stiffness to provide insight into its mechanisms and, ultimately, therapeutic targets for treating this pathology.

Increased Proximal Aortic Diameter is Associated With Risk of Cardiovascular Events and All-Cause Mortality in Blacks The Jackson Heart Study

BACKGROUND

Enlargement of the proximal aorta is associated with aortic wall tissue remodeling, including fragmentation of the elastin fibers, increased synthesis of collagen, and calcification, all of which are associated with aortic wall stiffening. We hypothesized that the proximal aortic diameter (AoD) is associated with cardiovascular events in a community-based cohort of blacks.

METHODS AND RESULTS

We investigated the associations between AoD and cardiovascular events among 3018 black participants (mean age, 55.9 years; 69% women) without past history of cardiovascular disease in the Jackson Heart Study. AoD was measured using echocardiography at the level of the sinuses of Valsalva at end diastole. Cardiovascular event was defined as incident myocardial infarction, fatal coronary artery disease, stroke, or heart failure hospitalization. Cox proportional hazards regression models were used to evaluate the association between baseline AoD and cardiovascular events. Over a median follow-up of 8.3 years, there were 258 cardiovascular events (incident rate, 10.5 per 1000 person-years). After adjustment for traditional risk factors, increased AoD was significantly associated with cardiovascular events (hazard ratio per 1-cm increase, 1.72; 95% CI, 1.10-2.69; P<0.05). Participants in the top AoD quintile had a higher incidence of cardiovascular events compared to those not in the top quintile (hazard ratio, 1.47; 95% CI, 1.11-1.94; P<0.005) after adjustment for risk factors.

CONCLUSIONS

Greater AoD was associated with an increased risk of cardiovascular events in a community-based cohort of blacks. AoD may be useful as a predictor of incident cardiovascular events and further investigation is warranted.

Twenty-Five-Year Alcohol Consumption Trajectories and Their Association With Arterial Aging: A Prospective Cohort Study

BACKGROUND

Emerging evidence suggests that arterial stiffness, an important marker of cardiovascular health, is associated with alcohol consumption. However, the role of longer-term consumption patterns in the progression of arterial stiffness over time remains unclear. A longitudinal cohort design was used to evaluate the association between alcohol consumption over 25 years and subsequent changes in arterial stiffness.

METHODS AND RESULTS

Data (N=3869; 73% male) were drawn from the Whitehall II cohort study of British civil servants, in which participants completed repeat pulse wave velocity assessments of arterial stiffness across a 4- to 5-year interval. Repeated alcohol intake measurements were used to categorize participants into alcohol consumer types, accounting for longitudinal variability in consumption. Sex-stratified linear mixed-effects modeling was used to investigate whether drinker types differed in their relationship to pulse wave velocity and its progression over time. Males with consistent long-term heavy intake >112 g of ethanol/week had significantly higher baseline pulse wave velocity (b=0.26 m/s; P=0.045) than those who drank consistently moderately (1-112 g of ethanol/week). Male former drinkers showed significantly greater increases in arterial stiffness longitudinally compared to consistently moderate drinkers (b=0.11 m/s; P=0.009). All associations were nonsignificant for females after adjustment for body mass index, heart rate, mean arterial pressure, diabetes mellitus, high-density lipoprotein, and triglycerides.

CONCLUSIONS

This work demonstrates that consistently heavy alcohol consumption is associated with higher cardiovascular risk, especially among males, and also provides new insights into the potential impact of changes in drinking levels over time. It discusses the additional insights possible when capturing longitudinal consumption patterns in lieu of reliance on recent intake alone.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02663791.

Vitamin D, carotid intima-media thickness and bone structure in patients with type 2 diabetes

Despite aggressive treatment of cardiovascular disease (CVD) risk factors individuals with type 2 diabetes (T2D) still have increased risk of cardiovascular morbidity and mortality. The primary aim of this study was to examine the cross-sectional association between total (25-hydroxy vitamin D (25(OH)D)) and risk of CVD in patients with T2D. Secondary objective was to examine the association between 25(OH)D and bone health. A Danish cohort of patients with T2D participating in a randomised clinical trial were analysed. In total 415 patients (68% men, age 60±9 years (mean±s.d.), duration of diabetes 12±6 years), including 294 patients (71%) treated with insulin. Carotid intima-media thickness (IMT) and arterial stiffness (carotid artery distensibility coefficient (DC) and Young's elastic modulus (YEM)) were measured by ultrasound scan as indicators of CVD. Bone health was assessed by bone mineral density and trabecular bone score measured by dual energy X-ray absorptiometry. In this cohort, 214 patients (52%) were vitamin D deficient (25(OH)D <50 nmol/l). Carotid IMT was 0.793±0.137 mm, DC was 0.0030±0.001 mmHg, YEM was 2354±1038 mmHg and 13 (3%) of the patients were diagnosed with osteoporosis. A 25(OH)D level was not associated with carotid IMT or arterial stiffness (P>0.3) or bone health (P>0.6) after adjustment for CVD risk factors. In conclusion, 25(OH)D status was not associated with carotid IMT, arterial stiffness or bone health in this cohort of patients with T2D. To explore these associations and the association with other biomarkers further, multicentre studies with large numbers of patients are required.