Ethnic differences in carotid wall thickness. The Insulin Resistance Atherosclerosis Study

Influence of Race and High Laminar Shear Stress on TNFR1 Signaling in Endothelial Cells

Tumor necrosis factor (TNF) binding to endothelial TNF receptor-I (TNFR-I) facilitates monocyte recruitment and chronic inflammation, leading to the development of atherosclerosis. In vitro data show a heightened inflammatory response and atherogenic potential in endothelial cells (ECs) from African American (AA) donors. High laminar shear stress (HSS) can mitigate some aspects of racial differences in endothelial function at the cellular level. We examined possible racial differences in TNF-induced monocyte adhesion and TNFR1 signaling complex expression/activity, along with the effects of HSS. Tohoku Hospital Pediatrics-1 (THP-1) monocytes were used in a co-culture system with human umbilical vein ECs (HUVECs) from Caucasian American (CA) and AA donors to examine racial differences in monocyte adhesion. An in vitro exercise mimetic model was applied to investigate the potential modulatory effect of HSS. THP-1 adherence to ECs and TNF-induced nuclear factor kappa B (NF-κB) DNA binding were elevated in AA ECs compared to CA ECs, but not significantly. We report no significant racial differences in the expression of the TNFR-I signaling complex. Application of HSS significantly increased the expression and shedding of TNFR-I and the expression of TRAF3, and decreased the expression of TRAF5 in both groups. Our data does not support TNF-induced NF-κB activation as a potential mediator of racial disparity in this model. Other pathways and associated factors activated by the TNFR1 signaling complex are recommended targets for future research.

Racial differences in all-cause mortality and future complications among people with diabetes: a systematic review and meta-analysis of data from more than 2.4 million individuals

AIMS/HYPOTHESIS

The aim of this work was to quantify racial/ethnic differences in risk for future diabetic complications and all-cause mortality by performing a meta-analysis of prospective studies.

METHODS

A systematic search in PubMed and EMBASE was performed from inception to May 2021. Prospective cohort studies that reported HRs and associated 95% CIs of diabetes complications and all-cause mortality among racial/ethnic groups, with White people as the reference group, were included. Study characteristics and HR estimates were extracted from each study. Estimates were pooled using random-effects inverse-variance model with the Hartung-Knapp-Sidik-Jonkman variance estimator.

RESULTS

A total of 23 studies were included, comprising 2,416,516 individuals diagnosed with diabetes (White 59.3%, Black 11.2%, Asian 1.3%, Hispanic-American 2.4%, Native American 0.2%, East Asian 1.9%, South Asian 0.8%, Pacific Islander 2.3%, Māori 2.4% and others 18.2%). Compared with White individuals with diabetes, individuals of Māori ethnicity were at higher risk for all-cause mortality (HR 1.88 [95% CI 1.61, 2.21]; I² = 7.1%), Hispanic-American individuals had a significantly lower risk for CVD (HR 0.66 [95% CI 0.53, 0.81]; I² = 0%) and Black individuals had higher risk for end-stage renal disease (HR 1.54 [95% CI 1.05, 2.24]; I² = 95.4%). No significant higher risk for diabetes complications was found in other racial/ethnic groups relative to White people.

CONCLUSIONS/INTERPRETATION

Racial/ethnic differences exist in the risk for future diabetic complications and all-cause mortality. Our results support the use of such categories for international diabetes clinical guideline recommendations until better predictors become available. Efforts to identify high-risk groups and to better control cardiovascular risk factors across ethnically diverse populations are therefore needed.

REGISTRATION

PROSPERO registration ID CRD42021239274.

Epidemiology of atherosclerotic carotid artery disease

Atherosclerotic carotid artery disease is a significant cause of stroke in the United States and globally. Its prevalence increases with age and it is more prevalent in men and White and Native-American populations. However, the outcomes related to carotid disease are worse in women and Black patients. Research suggests the disparities exist due to a multitude of factors, including disease pathophysiology, access to care, provider bias, and socioeconomic status. The prevalence of carotid stenosis in the general population is low (3%), and routine screening for carotid stenosis is not recommended in adults. Randomized clinical trials have shown benefits of stroke risk reduction with surgery (carotid endarterectomy or stenting) for symptomatic patients. Management is controversial in asymptomatic patients, as modern medical management has results equivalent to those of surgery and ongoing randomized clinical trials will address this important question. Carotid surgery is not appropriate in asymptomatic patients with limited life expectancy. Future work should explore comprehensive care models for care of patients with carotid disease and assessment of patient-reported outcomes to measure quality of care.

Cardiovascular Disease Risk Factor Burden During the Menopause Transition and Late Midlife Subclinical Vascular Disease: Does Race/Ethnicity Matter?

Background

The extent to which cardiovascular disease (CVD) risk factors across the menopause explain racial/ethnic differences in subclinical vascular disease in late midlife women is not well documented and was explored in a multi‐ethnic cohort.

Methods and Results

Participants (n=1357; mean age 60 years) free of clinical CVD from the Study of Women's Health Across the Nation had common carotid artery intima‐media thickness, interadventitial diameter, and carotid plaque presence assessed by ultrasonography on average 13.7 years after baseline visit. Early to late midlife time‐averaged cumulative burden of traditional CVD risk factors calculated using serial measures from baseline to the ultrasound visit were generally less favorable in black and Hispanic women compared with white and Chinese women, including education and smoking status and time‐averaged cumulative blood pressure, high‐density lipoprotein cholesterol, and fasting insulin. Independent of these risk factors, BMI, and medications, common carotid artery intima‐media thickness was thicker in black women, interadventitial diameter was wider in Chinese women, yet plaque presence was lower in black and Hispanic women compared with white women. CVD risk factor associations with subclinical vascular measures did not vary by race/ethnicity except for high‐density lipoprotein cholesterol on common carotid artery intima‐media thickness; an inverse association between high‐density lipoprotein cholesterol and common carotid artery intima‐media thickness was observed in Chinese and Hispanic but not in white or black women.

Conclusions

Race/ethnicity did not particularly moderate the association between traditional CVD risk factors measured across the menopause transition and late midlife subclinical vascular disease. Unmeasured socioeconomic, cultural, and nontraditional biological risk factors likely play a role in racial/ethnic differences in vascular health and merit further exploration.

Race and sex-based disparities associated with carotid endarterectomy in the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND AND AIMS

The indications for carotid endarterectomy (CEA) are well established. The aim of the current study was to investigate sex and race-based disparities in the incidence of CEA after adjusting for carotid artery stenosis risk factors.

METHODS

We conducted a prospective cohort analysis of 14,492 black and white participants in the Atherosclerosis Risk in Communities (ARIC) study without prevalent stroke at baseline (1987-1989). We used Kaplan-Meier curves and Cox proportional hazards models adjusting for sociodemographic, cardiovascular, and disease severity risk factors to quantify the associations of sex and race with incident CEA.

RESULTS

CEA was performed in 330 of 14,492 ARIC participants during a median of 27 years of follow-up [incidence rate 1.00 (95% CI 0.90-1.12) per 1000 persons-years]. The crude incidence of CEA varied significantly by sex [female vs. male: HR 0.60 (95% CI 0.48-0.74)] and race [black vs. white: HR 0.65 (95% CI 0.49-0.86)]. Adjustment for sociodemographic and cardiovascular risk factors, carotid intima-media thickness, and symptomatic status attenuated the association of sex with CEA [females vs. males HR 0.96 (0.76-1.22)], but black participants had a lower risk of incident CEA after adjustment [HR 0.68 (95% CI 0.49-0.95)].

CONCLUSIONS

We found significant variation in the incidence of CEA procedures based on race that was independent of traditional risk factors and carotid IMT. Whether this disparity is a reflection of differences in disease presentation or access to care deserves investigation.

Cardiovascular disease risk and its determinants in people living with HIV across different settings in South Africa

Objectives

Socio‐economic factors and lifestyle are known to differ across geographies and populations, which may result in distinct risk profiles for cardiovascular disease (CVD). This study assessed carotid intima‐media thickness (CIMT), a proxy for CVD, and its determinants in two groups of people living with HIV (PLHIV) in two different settings in South Africa.

Methods

A cross‐sectional analysis was conducted comparing data from the Ndlovu Cohort Study in the Limpopo Province (group 1) and from three clinical trials in Johannesburg (group 2). The association between demographics, conventional CVD risk factors, HIV‐related factors and CIMT in groups 1 and 2 was analysed with two separate multivariable linear regression models.

Results

Group 1 consisted of 826 participants (mean age 42.2 years) and mean (± standard deviation) CIMT was 0.626 ± 0.128 mm. In this group, sex, age, body mass index (BMI), cholesterol, glucose and antiretroviral therapy (ART) duration (β = 0.011 mm per 5 years; P = 0.02) were associated with higher CIMT. There were positive interactions between age and ART duration and age and cholesterol. Group 2 consisted of 382 participants (mean age 39.5 years) and mean (± standard deviation) CIMT was 0.560 ± 0.092 mm. In this group, only sex, education level, BMI and cholesterol were associated with higher CIMT, albeit with weaker associations than in group 1.

Conclusions

Conventional CVD risk factors were the main drivers of CIMT. The impact of some of these risk factors appeared to increase with age. Differences in sample size, age and viral suppression might explain why an effect of ART was observed in group 1 but not in group 2.

Race or vitamin D: A determinant of intima media thickness in obese adolescents?

OBJECTIVE

Carotid intima media thickness (IMT), a predictor of cardiovascular events, is reported to be higher in African-American (AA) vs White (AW) individuals. We investigated whether racial differences in IMT in obese adolescents could be explained by differences in 25 hydroxy-vitamin D [25(OH)D].

RESEARCH DESIGN AND METHODS

A total of 63 obese adolescents had 25(OH)D levels, determination of IMT, body composition, insulin sensitivity (IS) by hyperinsulinemic-euglycemic clamp, lipids and blood pressure (BP).

RESULTS

IMT was higher and 25(OH)D lower in AA vs AW. IMT correlated with 25(OH)D level (r = -0.38, P = .002) but not with IS. In multiple regression analysis, race, HbA1c, BP and age, and not 25(OH)D, BMI or IS, were the significant determinants of IMT (R² = 0.44, P < .001). Without race in the model, 25(OH)D (β = -0.36, P = .009) contributed to the variance in IMT (R² = 0.32, P = .007).

CONCLUSION

Obese AA adolescents vs AW, have higher IMT, explained by race, BP, and HbA1c. Although 25(OH)D levels contribute to the variance in IMT, the observed racial difference in IMT could be mediated through other unknown race-related factors besides 25(OH)D.

Socioeconomic Position Is Associated With Carotid Intima-Media Thickness in Mid-Childhood: The Longitudinal Study of Australian Children

BACKGROUND

Lower socioeconomic position (SEP) predicts higher cardiovascular risk in adults. Few studies differentiate between neighborhood and family SEP or have repeated measures through childhood, which would inform understanding of potential mechanisms and the timing of interventions. We investigated whether neighborhood and family SEP, measured biennially from ages 0 to 1 year onward, was associated with carotid intima-media thickness (IMT) at ages 11 to 12 years.

METHODS AND RESULTS

Data were obtained from 1477 families participating in the Child Health CheckPoint study, nested within the Longitudinal Study of Australian Children. Disadvantaged family and neighborhood SEP was cross-sectionally associated with thicker maximum carotid IMT in separate univariable linear regression models. Associations with family SEP were not attenuated in multivariable analyses, and associations with neighborhood SEP were attenuated only in models adjusted for family SEP. The difference in maximum carotid IMT between the highest and lowest family SEP quartile measured at ages 10 to 11 years was 10.7 μm (95% CI, 3.4-18.0; P=0.004), adjusted for age, sex, pubertal status, passive smoking exposure, body mass index, blood pressure, and arterial lumen diameter. In longitudinal analyses, family SEP measured as early as age 2 to 3 years was associated with maximum carotid IMT at ages 11 to 12 years (difference between highest and lowest quartile: 8.5 μm; 95% CI, 1.3-15.8; P=0.02). No associations were observed between SEP and mean carotid IMT.

CONCLUSIONS

We report a robust association between lower SEP in early childhood and carotid IMT in mid-childhood. Further investigation of mechanisms may inform pediatric cardiovascular risk assessment and prevention strategies.

Effect of acute aerobic exercise and histamine receptor blockade on arterial stiffness in African Americans and Caucasians

African Americans (AA) exhibit exaggerated central blood pressure (BP) and arterial stiffness measured by pulse wave velocity (PWV) in response to an acute bout of maximal exercise compared with Caucasians (CA). However, whether potential racial differences exist in central BP, elastic, or muscular arterial distensibility after submaximal aerobic exercise remains unknown. Histamine receptor activation mediates sustained postexercise hyperemia in CA but the effect on arterial stiffness is unknown. This study sought to determine the effects of an acute bout of aerobic exercise on central BP and arterial stiffness and the role of histamine receptors, in AA and CA. Forty-nine (22 AA, 27 CA) young and healthy subjects completed the study. Subjects were randomly assigned to take either histamine receptor antagonist or control placebo. Central blood BP and arterial stiffness measurements were obtained at baseline, and at 30, 60, and 90 min after 45 min of moderate treadmill exercise. AA exhibited greater central diastolic BP, elevated brachial PWV, and local carotid arterial stiffness after an acute bout of submaximal exercise compared with CA, which may contribute to their higher risk of cardiovascular disease. Unexpectedly, histamine receptor blockade did not affect central BP or PWV in AA or CA after exercise, but it may play a role in mediating local carotid arterial stiffness. Furthermore, histamine may mediate postexercise carotid arterial dilation in CA but not in AA. These observations provide evidence that young and healthy AA exhibit an exaggerated hemodynamic response to exercise and attenuated vasodilator response compared with CA.NEW & NOTEWORTHY African Americans are at greater risk for developing cardiovascular disease than Caucasians. We are the first to show that young and healthy African Americans exhibit greater central blood pressure, elevated brachial stiffness, and local carotid arterial stiffness following an acute bout of submaximal exercise compared with Caucasians, which may contribute to their higher risk of cardiovascular disease. Furthermore, African Americans exhibit attenuated vasodilator response compared with Caucasians.

Lifestyle Cardiovascular Risk Score, Genetic Risk Score, and Myocardial Infarction in Hispanic/Latino Adults Living in Costa Rica

BACKGROUND

A lifestyle cardiovascular risk score (LCRS) and a genetic risk score (GRS) have been independently associated with myocardial infarction (MI) in Hispanics/Latinos. Interaction or joint association between these scores has not been examined. Thus, our aim was to assess interactive and joint associations between LCRS and GRS, and each individual lifestyle risk factor, on likelihood of MI.

METHODS AND RESULTS

Data included 1534 Costa Rican adults with nonfatal acute MI and 1534 matched controls. The LCRS used estimated coefficients as weights for each factor: unhealthy diet, physical inactivity, smoking, elevated waist:hip ratio, low/high alcohol intake, low socioeconomic status. The GRS included 14 MI-associated risk alleles. Conditional logistic regressions were used to calculate adjusted odds ratios. The odds ratios for MI were 2.72 (2.33, 3.17) per LCRS unit and 1.13 (95% CI 1.06, 1.21) per GRS unit. A significant joint association for highest GRS tertile and highest LCRS tertile and odds of MI was detected (odds ratio=5.43 [3.71, 7.94]; P<1.00×10-7), compared to both lowest tertiles. The odds ratios were 1.74 (1.22, 2.49) under optimal lifestyle and unfavorable genetic profile, and 5.02 (3.46, 7.29) under unhealthy lifestyle but advantageous genetic profile. Significant joint associations were observed for the highest GRS tertile and the highest of each lifestyle component risk category. The interaction term was nonsignificant (P=0.33).

CONCLUSIONS

Lifestyle risk factors and genetics are jointly associated with higher odds of MI among Hispanics/Latinos. Individual and combined lifestyle risk factors showed stronger associations. Efforts to improve lifestyle behaviors could help prevent MI regardless of genetic susceptibility.

American Society of Echocardiography Report

Noninvasive measures of atherosclerosis have emerged as adjuncts to standard cardiovascular disease (CVD) risk factors in an attempt to refine risk stratification and the need for more aggressive preventive strategies. Two such approaches, carotid artery imaging and brachial artery reactivity testing (BART), are ultrasound based. Numerous carotid artery imaging protocols have been used, and methodologic aspects are described in detail in this review. The panel recommends that protocols: (1) use end-diastolic (minimum dimension) images for intimal-medial thickness (IMT) measurements; (2) provide separate categorization of plaque presence and IMT; (3) avoid use of a single upper limit of normal for IMT because the measure varies with age, sex, and race; and (4) incorporate lumen measurement, particularly when serial measurements are performed to account for changes in distending pressure. Protocols may vary in the number of segments wherein IMT is measured, whether near wall is measured in addition to far wall, and whether IMT measurements are derived from B-mode or M-mode images, depending on the application. BART is a technique that requires meticulous attention to patient preparation and methodologic detail. Its application is substantially more challenging than is carotid imaging and remains largely a research technique that is not readily translated into routine clinical practice.

Associations of Psychological Well-Being With Carotid Intima Media Thickness in African American and White Middle-Aged Women

OBJECTIVES

The present cross-sectional study aimed to a) examine associations between measures of psychological well-being, specifically life satisfaction and life engagement, and intima media thickness, a subclinical marker of atherosclerosis; b) investigate if the interaction of psychological well-being and life events correlated with intima media thickness; and c) explore these relationships across race.

METHODS

A sample of 485 women (38% African American and 62% white; mean [standard deviation] age = 50.2 [2.9] years) underwent ultrasonography to assess carotid artery intima media thickness (IMT). The women completed self-report measures of life satisfaction, life engagement, and life events.

RESULTS

Average (standard deviation) IMT was 0.666 (0.10) mm. Life satisfaction showed a significant, independent, inverse relationship with IMT, after controlling for demographic, behavioral, psychological, and cardiovascular covariates (β = -0.105, p = .039), such that each 1-point higher life satisfaction score was correlated with a significant 0.008-mm lower level of mean IMT. No significant association was seen between life events and IMT (r = 0.05, p = .32), and life satisfaction did not interact with life events on IMT (β = -0.036, p = .46). No significant interaction between life satisfaction and race on IMT was observed (β = 0.068, p = .37). In contrast to life satisfaction, life engagement was not a significant correlate of IMT (r = -0.07, p = .12).

CONCLUSIONS

Life satisfaction, a measure of psychological well-being, is an important independent correlate of subclinical atherosclerosis in middle-aged women.

Carotid Intima Media Thickness in Mainly Female HIV-Infected Subjects in Rural South Africa: Association With Cardiovascular but Not HIV-Related Factors

BACKGROUND

In sub-Saharan Africa, the number of persons living with human immunodeficiency virus (HIV) has increased immensely. In parallel, rates of noncommunicable diseases, especially cardiovascular disease, are rising rapidly in resource-limited settings. This study aims to evaluate the relation between subclinical atherosclerosis and HIV-related and traditional cardiovascular risk factors in HIV-infected patients in rural South Africa.

METHODS

A cross-sectional study was performed among HIV-infected patients visiting a health center in Limpopo, South Africa. Demographic and HIV-related information was collected, and cardiovascular risk was assessed. Carotid intima media thickness (CIMT) was measured and the prevalence of subclinical atherosclerosis (CIMT >0.78 mm) was calculated. The association between cardiovascular or HIV-related determinants with CIMT was analyzed using linear and logistic regression models adjusted for age and sex.

RESULTS

The median CIMT in 866 subjects (median age [interquartile range], 41 [35-48] years; 69% female) was 0.589 mm (interquartile range, 0.524-0.678 mm), and values seemed higher than in healthy Western reference populations. In fact 12% of subjects (106 of 866) had subclinical atherosclerosis. Hypertension, high body mass index, previous cardiovascular event, diabetes mellitus, total and low-density lipoprotein cholesterol, estimated glomerular filtration rate, metabolic syndrome, and the Framingham Heart Risk score were independently associated with CIMT. No HIV-related determinants were associated with CIMT.

CONCLUSIONS

In a predominantly female HIV-infected population in South Africa, CIMT values are considerably high and associated with cardiovascular risk factors, rather than HIV-related factors. This finding emphasizes the need to screen for cardiovascular disease among persons with HIV infection in resource-limited settings. Ideally, this screening would be integrated into care for chronic HIV infection, posing a major challenge for the future.

Nulliparity is associated with less healthy markers of subclinical cardiovascular disease in young women with overweight and obesity

OBJECTIVE

Higher parity is associated with increased subclinical cardiovascular disease (CVD) in mid-life and older women and with increased CVD risk overall. The relationship between parity, subclinical CVD, and infertility in young women with overweight and obesity has been infrequently evaluated.

METHODS

Reproductive histories were obtained in 191 (66%) young women with overweight and obesity (BMI 25-39.9 kg/m(2) ) participating in a weight loss trial. Baseline carotid intima-media thickness (IMT) and inter-adventitial diameter (IAD) were assessed via B-mode ultrasound. Linear regression was used to estimate the relationship between parity and carotid measures, adjusted for demographic, cardiovascular, and reproductive risk factors.

RESULTS

Nulliparous women (n = 70, age 34.9 ± 7.1) had increased common carotid IAD (0.230 mm, SE 0.08, P = 0.003) and mean common carotid artery (CCA) IMT (0.031 mm, SE 0.01, P = 0.007) compared with parous women (n = 102, age 39.5 ± 4.9), persisting after adjustment for age, race, and CVD risk factors. No other reproductive factors were statistically significantly associated.

CONCLUSIONS

Nulliparity is associated with markers of less healthy carotid arteries in a sample of disease-free 25- to 45-year-old women with overweight or obesity. This may represent a beneficial effect of pregnancy or indicate overall better health in women with overweight/obesity who are capable of childbearing.

Genetic ancestry is associated with measures of subclinical atherosclerosis in African Americans: the Jackson Heart Study

OBJECTIVE

To determine whether genetic ancestry was associated with subclinical atherosclerosis measures after adjustment for traditional cardiovascular disease risk factors, inflammatory marker, socioeconomic status, and psychosocial factors in a large admixed African American population.

APPROACH AND RESULTS

Participants were drawn from the Jackson Heart Study. Participant's percent of European ancestry (PEA) was estimated based on 1747 genetic markers using HAPMIX. Association of PEA with peripheral arterial disease and common carotid intima-media thickness were investigated among 2168 participants and with coronary artery calcification >0 and abdominal aortic calcification >0 among 1139 participants. The associations were evaluated using multivariable regression models. Our results showed that a 1 SD increase in PEA was associated with a lower peripheral arterial disease prevalence after adjusting for age and sex (prevalence ratio=0.90 [95% CI, 0.82-0.99]; P=0.036). Adjustments for traditional cardiovascular disease risk factors, socioeconomic status, and psychosocial factors attenuated this association (prevalence ratio=0.91 [0.82-1.00]; P=0.046). There was also a nonlinear association between PEA and coronary artery calcification and abdominal aortic calcification. The lowest PEA was associated with a lower coronary artery calcification (prevalence ratio=0.75 [0.58-0.96]; P=0.022) and a lower abdominal aortic calcification [prevalence ratio=0.80 [0.67-0.96]; P=0.016) compared with the reference group (10th-90th percentile) after adjusting for traditional cardiovascular disease risk factors, inflammatory marker, socioeconomic status, and psychosocial factors. However, we found no significant association between PEA and common carotid intima-media thickness.

CONCLUSIONS

Overall, our findings indicate that genetic ancestry was associated with subclinical atherosclerosis, suggesting unmeasured risk factors and interactions with genetic factors might contribute to the distribution of subclinical atherosclerosis among African Americans.

Status of cardiovascular disease and stroke in Hispanics/Latinos in the United States: a science advisory from the American Heart Association

BACKGROUND AND PURPOSE

This American Heart Association (AHA) scientific statement provides a comprehensive overview of current evidence on the burden cardiovascular disease (CVD) among Hispanics in the United States. Hispanics are the largest minority ethnic group in the United States, and their health is vital to the public health of the nation and to achieving the AHA's 2020 goals. This statement describes the CVD epidemiology and related personal beliefs and the social and health issues of US Hispanics, and it identifies potential prevention and treatment opportunities. The intended audience for this statement includes healthcare professionals, researchers, and policy makers.

METHODS

Writing group members were nominated by the AHA's Manuscript Oversight Committee and represent a broad range of expertise in relation to Hispanic individuals and CVD. The writers used a general framework outlined by the committee chair to produce a comprehensive literature review that summarizes existing evidence, indicate gaps in current knowledge, and formulate recommendations. Only English-language studies were reviewed, with PubMed/MEDLINE as our primary resource, as well as the Cochrane Library Reviews, Centers for Disease Control and Prevention, and the US Census data as secondary resources. Inductive methods and descriptive studies that focused on CVD outcomes incidence, prevalence, treatment response, and risks were included. Because of the wide scope of these topics, members of the writing committee were responsible for drafting individual sections selected by the chair of the writing committee, and the group chair assembled the complete statement. The conclusions of this statement are the views of the authors and do not necessarily represent the official view of the AHA. All members of the writing group had the opportunity to comment on the initial drafts and approved the final version of this document. The manuscript underwent extensive AHA internal peer review before consideration and approval by the AHA Science Advisory and Coordinating Committee.

RESULTS

This statement documents the status of knowledge regarding CVD among Hispanics and the sociocultural issues that impact all subgroups of Hispanics with regard to cardiovascular health. In this review, whenever possible, we identify the specific Hispanic subgroups examined to avoid generalizations. We identify specific areas for which current evidence was less robust, as well as inconsistencies and evidence gaps that inform the need for further rigorous and interdisciplinary approaches to increase our understanding of the US Hispanic population and its potential impact on the public health and cardiovascular health of the total US population. We provide recommendations specific to the 9 domains outlined by the chair to support the development of these culturally tailored and targeted approaches.

CONCLUSIONS

Healthcare professionals and researchers need to consider the impact of culture and ethnicity on health behavior and ultimately health outcomes. There is a need to tailor and develop culturally relevant strategies to engage Hispanics in cardiovascular health promotion and cultivate a larger workforce of healthcare providers, researchers, and allies with the focused goal of improving cardiovascular health and reducing CVD among the US Hispanic population.

Lean body mass may explain apparent racial differences in carotid intima-media thickness in obese children

BACKGROUND

Racial differences in carotid intima-media thickness (cIMT) have been suggested to be associated with the disproportionally high prevalence of cardiovascular disease in black adults. The objective of this study was to evaluate the effects of cardiovascular risk factors on the racial differences seen in cIMT in obese children.

METHODS

Obese subjects aged 4 to 21 years were recruited prospectively. Height, weight, blood pressure, fasting insulin, glucose, lipid panel, high-sensitivity C-reactive protein, and body composition by dual-energy x-ray absorptiometry were obtained. B-mode carotid imaging was analyzed by a single blinded physician.

RESULTS

A total of 120 subjects (46 white, 74 black) were enrolled. Black subjects exhibited greater cIMT (0.45 ± 0.03 vs 0.43 ± 0.02 cm, P < .01) and higher lean body mass index (19.3 ± 3.4 vs 17.3 ± 3.2 kg/m², P = .02) than white subjects. Simple linear regression revealed modest associations between mean cIMT and race (R = 0.52, P < .01), systolic blood pressure (R = 0.47, P < .01), and lean body mass (R = 0.51, P < .01). On multivariate regression analysis, lean body mass remained the only measure to maintain a statistically significant relationship with mean cIMT (P < .01).

CONCLUSIONS

Black subjects demonstrated greater cIMT than white subjects. The relationship between race and cIMT disappeared when lean body mass was accounted for. Future studies assessing the association of cardiovascular disease risk factors to cIMT in obese children should include lean body mass in the analysis.

Effects of moderate aerobic exercise training on vascular health and blood pressure in African Americans

As healthcare progresses toward individualized medicine, understanding how different racial groups respond to lifestyle interventions is valuable. It is established that African Americans have disproportionate levels of cardiovascular disease and impaired vascular health, and clinical practice guidelines suggest lifestyle interventions as the first line of treatment. Recently, the authors reported that 6 months of aerobic exercise improved inflammatory markers, flow-mediated dilation (FMD), and levels of circulating endothelial microparticles (EMPs) in African American adults. This study is a subgroup analysis of the aerobic exercise-induced changes in vascular health and blood pressure (BP) measures, including carotid artery intima-media thickness (IMT), nitroglycerin-mediated dilation (NMD), ambulatory BP, and office BP. Sedentary African American adults (53.4±6.2 years; 21 women and 5 men) showed improved vascular health but no change in BP. Carotid artery IMT decreased 6.4%, plasma nitric oxide levels increased 76.6%, plasma EMP levels decreased, percentage of FMD increased 59.6%, and FMD/NMD ratio increased 36.2% (P<.05 for all). Six months of aerobic exercise training is sufficient to elicit improvements in vascular structure and function in African Americans, even without improvements in BP measures or NMD (ie, smooth muscle function). To our knowledge, this is the first study to report such findings in African Americans.

Differences in vascular nitric oxide and endothelium-derived hyperpolarizing factor bioavailability in blacks and whites

OBJECTIVE

Abnormalities in nitric oxide (NO) bioavailability have been reported in blacks. Whether there are differences in endothelium-derived hyperpolarizing factor (EDHF) in addition to NO between blacks and whites and how these affect physiological vasodilation remain unknown. We hypothesized that the bioavailability of vascular NO and EDHF, at rest and with pharmacological and physiological vasodilation, varies between whites and blacks.

APPROACH AND RESULTS

In 74 white and 86 black subjects without known cardiovascular disease risk factors, forearm blood flow was measured using plethysmography at rest and during inhibition of NO with N(G)-monomethyl-L-arginine and of K(+) Ca channels (EDHF) with tetraethylammonium. The reduction in resting forearm blood flow was greater with N(G)-monomethyl-L-arginine (P=0.019) and similar with tetraethylammonium in whites compared with blacks. Vasodilation with bradykinin, acetylcholine, and sodium nitroprusside was lower in blacks compared with whites (all P<0.0001). Inhibition with N(G)-monomethyl-L-arginine was greater in whites compared with blacks with bradykinin, acetylcholine, and exercise. Inhibition with tetraethylammonium was lower in blacks with bradykinin, but greater during exercise and with acetylcholine.

CONCLUSIONS

The contribution to both resting and stimulus-mediated vasodilator tone of NO is greater in whites compared with blacks. EDHF partly compensates for the reduced NO release in exercise and acetylcholine-mediated vasodilation in blacks. Preserved EDHF but reduced NO bioavailability and sensitivity characterizes the vasculature in healthy blacks.

CLINICAL TRIAL REGISTRATION URL

http://clinicaltrials.gov/. Unique identifier: NCT00166166.

Low-grade albuminuria is associated with early but not late carotid atherosclerotic lesions in community-based patients with type 2 diabetes

Background

Low-grade albuminuria is associated with cardiovascular risk factors and mortality. Our aim was to investigate the association between low-grade albuminuria and carotid atherosclerotic lesions in community-based patients with type 2 diabetes.

Methods

A cross-sectional study was performed in 475 community-based patients with type 2 diabetes (190 males and 285 females) with normal urinary albumin-to-creatinine ratios (UACR) (< 3.5 mg/mmol) from Shanghai, China. The subjects were stratified into tertiles based on UACR levels (the lowest tertile was UACR ≤ 1.19 mg/mmol, and the highest tertile was UACR ≥ 2 mg/mmol). Carotid intima-media thickness (CIMT), carotid atherosclerotic plaque formation and stenosis were assessed and compared among the three groups based on ultrasonography. The urinary albumin excretion rate was determined as the mean of the values obtained from three separate early morning urine samples.

Results

Compared with the subjects with UACR in the lowest tertile, the subjects with UACR in the middle and highest tertiles had greater CIMT values (0.88 ± 0.35 mm, 0.99 ± 0.43 mm and 1.04 ± 0.35 mm, respectively; all p < 0.05) and a higher prevalence of carotid atherosclerotic plaques (25.3%, 39.0% and 46.2%, respectively; all p < 0.05) after adjusting for sex and age. Fully adjusted multiple linear regression and logistic regression analyses revealed that UACR tertiles were significantly associated with elevated CIMT (p = 0.007) and that, compared with the subjects in the first tertile of UACR, those in the second and third tertiles had 1.878- and 2.028-fold risk of carotid plaques, respectively. However, there was no statistical association between UACR tertile and the prevalence of carotid stenosis.

Conclusions

Higher UACR within the normal range was independently associated with early but not late carotid atherosclerotic lesions in community-based patients with type 2 diabetes. Low-grade albuminuria contributes to the risk of carotid atherosclerosis and may be used as an early marker for the detection of atherosclerosis in patients with type 2 diabetes.

Pulse pressure and subclinical cardiovascular disease in the multi-ethnic study of atherosclerosis

BACKGROUND

Brachial pulse pressure (PP) has been found to be associated with markers of subclinical cardiovascular disease, including carotid intima-media thickness and left-ventricular mass index (LVMI), but it is unclear whether these associations are independent of traditional cardiovascular risk factors and of the steady, nonpulsatile component of blood pressure (BP). Moreover, it is unknown whether these associations are modified by gender, age, or race/ethnicity.

METHODS

We used multivariate linear regression models to assess the relationship between brachial PP and three markers of subclinical cardiovascular disease (CVD) (common carotid intima-media thickness (CC-IMT), internal carotid intima-media thickness (IC-IMT), and LVMI) in four race/ethnic groups in the Multi-Ethnic Study of Atherosclerosis. The models were adjusted for traditional Framingham risk factors (age, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, diabetes, smoking status), use of lipid-lowering medication, use of antihypertensive medication, study site, and mean arterial pressure (MAP).

RESULTS

The assessment was done on 6,776 participants (2,612 non-Hispanic white, 1,870 African-American, 1,494 Hispanic, and 800 Chinese persons). The associations between brachial PP and CC-IMT, IC-IMT, and LVMI were significant in fully adjusted models. The three subclinical markers also showed significant interactions with gender (P < 0.0001), with stronger interactions in men. There was an interaction with age for LVMI (P = 0.004) and IC-IMT (P = 0.008). Race/ethnicity modified the association of PP with CC-IMT.

CONCLUSIONS

Brachial PP was independently associated with subclinical CVD after adjustment for cardiovascular risk factors and mean arterial pressure (MAP). The strength of the association differed significantly for strata of gender, age, and race/ethnicity.

Survey of atherosclerotic disease in Asian subjects with cardiovascular disease risk factors who were not receiving lipid-lowering agents

BACKGROUND

Carotid intima media thickness (CIMT) is a surrogate marker for atherosclerosis, used to identify asymptomatic individuals at increased risk of cardiovascular events. The primary objective of this study was to obtain the distribution of CIMT measurements in Asian individuals with cardiovascular disease (CVD) risk factors who were not receiving lipid-lowering agents.

METHODS

Mean CIMT based on ultrasonographic measurement of 12 sites within the common carotid artery was recorded for 2726 subjects across eight Asian countries who had two or more CVD risk factors but were not receiving lipid-lowering therapy. CVD risk factors and lipid and glucose profiles were analyzed with respect to distribution of CIMT and high-sensitivity C-reactive protein (hs-CRP) values.

RESULTS

The overall mean (SD) of mean CIMT (mean-mean CIMT) was 0.662 (0.16) mm. There was a significant variation in mean-mean CIMT across countries (P<0.0001). Mean-mean CIMT values (mm) by age were: 0.485, 0.527, 0.614, 0.665, 0.715 and 0.797 for ≤ 29, 30-39, 40-49, 50-59, 60-69 and ≥ 70 years, respectively. Multivariate analyses confirmed a significant association between increasing mean-mean CIMT and increasing age, male gender, low high-density lipoprotein-cholesterol (HDL-C) levels and elevated fasting blood glucose levels. Analysis of log-transformed hs-CRP levels showed significant association with increasing waist circumference, low-density lipoprotein-cholesterol, body-mass index, high blood glucose levels and low HDL-C.

CONCLUSIONS

Our data show normative mean-mean CIMT data for Asian subjects with two or more CVD risk factors who are not receiving lipid-lowering therapy, which may guide CVD risk-stratification of asymptomatic individuals in Asia.

The burden of non-communicable disease in transition communities in an Asian megacity: baseline findings from a cohort study in Karachi, Pakistan

Background

The demographic transition in South Asia coupled with unplanned urbanization and lifestyle changes are increasing the burden of non-communicable disease (NCD) where infectious diseases are still highly prevalent. The true magnitude and impact of this double burden of disease, although predicted to be immense, is largely unknown due to the absence of recent, population-based longitudinal data. The present study was designed as a unique ‘Framingham-like’ Pakistan cohort with the objective of measuring the prevalence and risk factors for hypertension, obesity, diabetes, coronary artery disease and hepatitis B and C infection in a multi-ethnic, middle to low income population of Karachi, Pakistan.

Methods

We selected two administrative areas from a private charitable hospital’s catchment population for enrolment of a random selection of cohort households in Karachi, Pakistan. A baseline survey measured the prevalence and risk factors for hypertension, obesity, diabetes, coronary artery disease and hepatitis B and C infection.

Results

Six hundred and sixty-seven households were enrolled between March 2010 and August 2011. A majority of households lived in permanent structures (85%) with access to basic utilities (77%) and sanitation facilities (98%) but limited access to clean drinking water (68%). Households had high ownership of communication technologies in the form of cable television (69%) and mobile phones (83%). Risk factors for NCD, such as tobacco use (45%), overweight (20%), abdominal obesity (53%), hypertension (18%), diabetes (8%) and pre-diabetes (40%) were high. At the same time, infectious diseases such as hepatitis B (24%) and hepatitis C (8%) were prevalent in this population.

Conclusion

Our findings highlight the need to monitor risk factors and disease trends through longitudinal research in high-burden transition communities in the context of rapid urbanization and changing lifestyles. They also demonstrate the urgency of public health intervention programs tailored for these transition communities.

Serum osteocalcin level and its association with carotid atherosclerosis in patients with type 2 diabetes

Objective

To investigate the association of serum osteocalcin with carotid atherosclerosis in patients with type 2 diabetes.

Methods

We performed a cross-sectional community-based study in metropolitan area. Serum total osteocalcin was measured by radioimmunoassay in 382 men and 435 postmenopausal women. The carotid artery intima-media thickness (IMT) and carotid plaques (PLQ) were measured by B-mode ultrasound.

Results

The crude mean of serum osteocalcin concentrations were 4.52±2.43 ng/ml for men and 5.75±2.92 ng/ml for postmenopausal women (P <0.001), respectively. Osteocalcin levels were associated inversely with age, fasting serum insulin, HOMA-IR, ALT, triglycerides, total cholesterol, LDL- cholesterol, CRP (all P<0.001) and positively with adiponectin and HOMA-B (all P<0.05). After multiple adjustment, the odds ratios (ORs) were substantially higher risk for carotid plaques (OR 1.77 for 1 SD decrease in osteocalcin, 95% CI 1.23-2.76, p=0.005). These associations remained significant after further adjustment for potential confounder.

Conclusions

Serum osteocalcin levels is an independent risk factor for carotid atherosclerosis in patients with type 2 diabetes.

Vitamin D and Parathyroid Hormone Relationships with Urinary Nitric Oxide Metabolites and Plasma Isoprostanes in African-Americans

BACKGROUND: Vitamin D deficiency and secondary rises in parathyroid hormone (PTH) are highly prevalent in obese African-Americans. Endothelial dysfunction related to oxidative stress is more common in African-Americans compared to whites. Currently, the association of vitamin D (25-hydroxyvitamin D, 25-OH D) and PTH to nitric oxide metabolites (NOx) - nitrate and nitrite - and oxidative stress in African-Americans is unknown. Objective: A cross-sectional design was utilized to determine the association of 25-OH D and PTH with urinary NOx (UNOx) (n = 101) and plasma isoprostanes (n = 125), an oxidative stress marker, in overweight (body mass index of 25-39.9), normotensive African-Americans aged ≥35 years. Measurements: Multivariable linear regression analysis adjusted for age, sex, body mass index, and season was used to determine the relationship of 25-OH D and PTH to UNOx and isoprostanes. General linear models, adjusted for the same covariates, contrasted UNOx across three mutually exclusive vitamin D/PTH groups: (1) normal 25-OH D (51-249 nmol/l) and normal PTH (≤65 pg/ml); (2) low 25-OH D and normal PTH, and (3) low 25-OH D and high PTH. RESULTS: 25-OH D was directly associated with UNOx before (p = 0.02) and after (p = 0.03) adjustment for PTH levels. A borderline significant association was observed between PTH and isoprostanes (p = 0.08). UNOx was 424, 290, and 270 μmol/8 h, respectively, across vitamin D/PTH groups 1-3 (p = 0.08). CONCLUSION: 25-OH D was directly associated with NO availability and PTH was positively, though borderline, associated with isoprostanes in overweight, normotensive adult African-Americans.

High prevalence of subclinical atherosclerosis by carotid ultrasound among Mexican Americans: discordance with 10-year risk assessment using the Framingham risk score

BACKGROUND

Framingham risk scores (FRS) were validated in a mostly Caucasian population. Evaluation of subclinical atherosclerosis by carotid ultrasound may improve ascertainment of risk in nonwhite populations. This study aimed to evaluate carotid intima-media thickness (cIMT) and carotid plaquing among Mexican Americans, and to correlate these markers with coronary risk factors and the FRS.

METHODS/RESULTS

Participants (n = 141) were drawn from the Cameron County Hispanic Cohort. Carotid artery ultrasound was performed and cIMT measured. Carotid plaque was defined as areas of thickening >50% of the thickness of the surrounding walls. Mean age was 53.1 ± 11.7 years (73.8% female). Most were overweight or obese (88.7%) and more than half (53.2%) had the metabolic syndrome. One third (34.8%) had abnormal carotid ultrasound findings (either cIMT ≥75th percentile for gender and age or presence of plaque). Among those with abnormal carotid ultrasound, the majority were classified as being at low 10-year risk for cardiovascular events. Carotid ultrasound reclassified nearly a third of the cohort as being at high risk. This discordance between 10-year FRS and carotid ultrasound was noted whether risk was assessed for hard coronary events or global risk. Concordance between FRS and carotid ultrasound findings was best when long-term (30-year) risk was assessed and no subject with an abnormal carotid ultrasound was categorized as low risk by the 30-year FRS algorithm.

CONCLUSIONS

Integration of carotid ultrasound findings to coronary risk assessments and use of longer term prediction models may provide better risk assessment in this minority population, with earlier initiation of appropriate therapies.

Cholesterol is associated with the presence of a lipid core in carotid plaque of asymptomatic, young-to-middle-aged African Americans with and without HIV infection and cocaine use residing in inner-city Baltimore, Md., USA

BACKGROUND

Stroke remains a leading cause of death in the United States. While stroke-related mortality in the USA has declined over the past decades, stroke death rates are still higher for blacks than for whites, even at younger ages. The purpose of this study was to estimate the frequency of a lipid core and explore risk factors for its presence in asymptomatic, young-to-middle-aged urban African American adults recruited from inner-city Baltimore, Md., USA.

METHODS

Between August 28, 2003, and May 26, 2005, 198 African American participants aged 30-44 years from inner-city Baltimore, Md., were enrolled in an observational study of subclinical atherosclerosis related to HIV and cocaine use. In addition to clinical examinations and laboratory tests, B-mode ultrasound for intima-media thickness of the internal carotid arteries was performed. Among these 198, 52 were selected from the top 30th percentile of maximum carotid intima-media thickness by ultrasound, and high-resolution black blood MRI images were acquired through their carotid plaque before and after the intravenous administration of gadodiamide. Of these 52, 37 with maximum segmental thickness by MRI >1.0 mm were included in this study. Lumen and outer wall contours were defined using semiautomated analysis software. The frequency of a lipid core in carotid plaque was estimated and risk factors for lipid core presence were explored using logistic regression analysis.

RESULTS

Of the 37 participants in this study, 12 (32.4%) were women. The mean age was 38.7 ± 4.9 years. A lipid core was present in 9 (17%) of the plaques. Seventy percent of the study participants had a history of cigarette smoking. The mean total cholesterol level was 176.1 ± 37.3 mg/dl, the mean systolic blood pressure was 113.1 ± 13.3 mm Hg, and the mean diastolic blood pressure was 78.9 ± 9.5 mm Hg. There were 5 participants with hypertension (13.5%). Twelve (32%) participants had a history of chronic cocaine use, and 23 (62%) were HIV positive. Among the factors investigated, including age, sex, blood pressure, cigarette smoking, C-reactive protein, fasting glucose, triglycerides, serum total cholesterol, coronary calcium, cocaine use, and HIV infection, only total cholesterol was significantly associated with the presence of a lipid core.

CONCLUSIONS

This study revealed an unexpectedly high rate of the presence of lipid core in carotid plaque and highlights the importance of cholesterol lowering to prevent cerebrovascular disease in this population. Further population-based studies are warranted to confirm these results.

Serum CXC ligand 5 is a new marker of subclinical atherosclerosis in type 2 diabetes

OBJECTIVE

To assess the relationship between serum chemokine CXC ligand 5 (CXCL5) and intima-media thickness (IMT) of the common carotid artery, a marker of preclinical atherosclerosis.

DESIGN, PATIENTS AND MEASUREMENTS

We measured the IMT (mean of three segments of both carotid arteries by ultrasonography), serum CXCL5, fasting plasma glucose, serum insulin, serum urea, serum uric acid, HbA1c, serum CRP, adiponectin and lipid profile of 730 Chinese type 2 diabetic participants older than 30 years in a cross-sectional community-based study performed in downtown Shanghai.

RESULTS

Serum CXCL5 correlated with carotid IMT (r = 0·112, P = 0·019) after adjustment for age, gender, serum CRP and HbA1c. Multivariate linear regression analysis demonstrated that age (P = 2·30 × 10(-7) ), gender (P = 2·70 × 10(-2) ), systolic blood pressure (P = 9·26 × 10(-3) ), serum CRP (P = 2·12 × 10(-2) ), low-density lipoprotein cholesterol (P = 2·40 × 10(-2) ), CXCL5 (P = 5·27 × 10(-3) ) and high-density lipoprotein cholesterol (P = 3·80 × 10(-3) ) were independently associated with carotid IMT.

CONCLUSIONS

Serum CXCL5 is an important determinant of carotid artery IMT in patients with type 2 diabetes. The correlation is independent of inflammation and glucose control.

Serum uric acid level and its association with metabolic syndrome and carotid atherosclerosis in patients with type 2 diabetes

Objective

We aimed to investigate whether elevated serum uric acid concentrations are associated with higher risk of metabolic syndrome (MetS) and carotid atherosclerosis in patients with type 2 diabetes.

Methods

We conducted a population-based cross-sectional survey in Shanghai, with a total of 395 men and 631 women age 41 to 92 years. The carotid artery intima-media thickness (IMT) and carotid atherosclerotic plaques (PLQ) were measured by B-mode ultrasound. MetS was defined according to the updated National Cholesterol Education Program Adult Treatment Panel III criteria for Asian Americans.

Results

Uric acid levels were negatively associated with duration of diabetes, fasting plasma glucose, glycohemoglobin, eGFR, HDL-cholesterol (all P < 0.001) and positively with BMI, CRP, waist circumference, triglycerides, systolic blood pressure, ACR, HOMA-IR and IMT (all P < 0.05). In the highest quartile of uric acid levels, the risks were substantially higher for MetS [odds ratio 3.97, (95% confidence interval 2.58-6.13)] (P < 0.001 for trend) and PLQ [odds ratio 2.71 (95% confidence interval 1.62-4.47)] (p = 0.013 for trend) compared with that in the lowest quartile of uric acid levels after multiple adjustment. These associations remained significant after further adjustment for potential confounders.

Conclusions

Serum uric acid level is associated with MetS and is an independent risk factor for carotid atherosclerosis in patients with type 2 diabetes.

Carotid artery intima-media thickness in college students: race/ethnicity matters

OBJECTIVE

Racial/ethnic differences in common carotid artery intima-media thickness (CIMT) and in risk factors associated with CIMT have been predominantly observed in middle-aged and older individuals. We aimed to characterize racial/ethnic differences CIMT and other cardiovascular risk factors in a healthy, young-adult population.

METHODS

College students were recruited as part of a study to characterize determinants of atherogenesis. Students were eligible if they were lifetime non-smokers, lived in the United States since six months of age, and attended high school in the United States. Blood pressure, heart rate, height, and weight were measured, B-mode carotid ultrasound was performed, questionnaires were administered and a 12-h fasting blood sample was collected. Associations between CIMT and other variables were assessed in 768 students aged 18-25 years using linear regression analysis.

RESULTS

In models adjusted for common cardiovascular risk factors, sex exhibited the strongest influence on CIMT, with men having 15.4 μm larger CIMT compared to women (95%CI 6.6, 24.2). Race/ethnicity was also strongly associated with CIMT. African Americans had 17.3 μm greater CIMT (95%CI -0.3, 34.8) compared to non Hispanic Whites, whereas Asians and Hispanic Whites had 14.3 (95%CI -24.3, -4.4) and 15.4 (95%CI -26.2, -4.7) μm smaller CIMT, respectively. BMI and systolic blood pressure were positively associated with CIMT.

CONCLUSION

The risk factors associated with atherogenesis later in life are already present and observable in college-aged young adults, so targeted campaigns to reduce life-long cardiovascular disease burden should be initiated earlier in life to improve public health.

Correlates of coronary artery calcified plaque in blacks and whites with type 2 diabetes

PURPOSE

To examine whether the relationship between cardiovascular disease risk factors and coronary artery calcification (CAC) is modified by race among those with diabetes.

METHODS

Data were pooled data from three studies (Multi-Ethnic Study of Atherosclerosis, Family Heart Study, Diabetes Heart Study) for a total of 835 blacks and 1122 whites with diabetes. CAC was quantified by cardiac computed tomography and risk factors were obtained using standard methods. Regression models examined the relationship between risk factors and presence and quantity of CAC.

RESULTS

The average age of the cohort was 60 years; 57% were women. Presence of CAC was lower in blacks compared to whites (odds ratio = 0.22 for men, 0.57 for women, p <0.01). Hemoglobin A1c, duration of diabetes, low-density lipoprotein, smoking, and body mass index were independently associated with presence of CAC; high-density lipoprotein, triglycerides, and C-reactive protein were not. Race did not modify these associations. Adjustment for multiple risk factors did not explain the race disparity in CAC.

CONCLUSIONS

CAC was reduced in blacks compared to whites in persons with diabetes. This effect was most pronounced in men. The relationship between risk factors and CAC did not differ between races. Racial differences in CAC are likely due to unmeasured risk factors and/or genetic susceptibility.

Ethnic differences in common carotid intima-media thickness, and the relationship to cardiovascular risk factors and peripheral arterial disease: the Ethnic-Echocardiographic Heart of England Screening Study

OBJECTIVE

To compare the mean and maximum common carotid intima-media thickness (CCIMT) in Blacks (Black Caribbean and Black African) and South Asians (People originating from India, Pakistan and Bangladesh) in a population survey and make associations with established cardiovascular risk factors and peripheral arterial disease (PAD).

PATIENTS AND METHODS

A subset of 492 (293 South Asians and 199 Blacks) out of 572 participants aged ≥ 45 years recruited in a sub-study to the Ethnic-Echocardiographic Heart of England Screening (E-ECHOES) epidemiological study had mean and maximum CCIMT measured. A questionnaire, anthropometric measurements and Ankle Brachial Pressure Index (ABPI) and Intermittent Claudication assessments were made.

RESULTS

Black participants had greater mean but not maximum CCIMT when compared to South Asians overall (P = 0.022), in men (P = 0.04) and in women (P = 0.044). Black ethnicity was an independent predictor of CCIMT even after adjustment for traditional cardiovascular risk factors (P < 0.05). After adjustment for age, ethnicity and traditional cardiovascular risk factors, the presence of PAD remained independently predictive of mean (P = 0.019) and maximum (P = 0.012) CCIMT.

CONCLUSION

Black ethnicity is related to greater mean and maximum CCIMT when compared to South Asians, even after adjusting for traditional cardiovascular risk factors. The presence of PAD independently predicts mean and maximum CCIMT adjusting for ethnicity, age and cardiovascular risk factors.

Genetic risk score and risk of myocardial infarction in Hispanics

BACKGROUND

Genome-wide association studies have identified loci associated with coronary heart disease in whites of European ancestry. This study evaluated whether genetic markers previously identified in whites are associated with nonfatal acute myocardial infarction (MI) in Hispanics.

METHODS AND RESULTS

Cases (n=1989) with a first nonfatal acute MI and population-based controls (n=2096) living in Costa Rica were studied. Fourteen single-nucleotide polymorphisms were genotyped. Seven single-nucleotide polymorphisms at 3 independent loci showed significant associations with MI. The odds ratios for the loci with the strongest associations were 1.16 (95 confidence interval [CI], 1.05 to 1.27) for rs4977574 (CDKN2A/2B), 1.15 (95 CI, 1.03 to 1.29) for rs646776 (CELSR2-PSRC1-SORT1), and 1.22 (95 CI, 1.08 to 1.38) for rs501120 (CXCL12); the corresponding PARs were 6.8, 10.5, and 15.2; respectively. We developed a genetic risk score by summing the number of the top 3 associated risk alleles. The OR for MI per genetic risk score unit was 1.18 (95 CI, 1.11 to 1.25; P=4.83 × 10(-8)). Discrimination of MI was significantly improved (P=0.02) when the genetic risk score was added to a model including clinical predictors. However, the increase in the area under the receiver-operating characteristic curve after the genetic risk score was added was moderate, from 0.67 (95 CI, 0.65 to 0.69) to 0.68 (95 CI, 0.66 to 0.70).

CONCLUSIONS

These results indicate both the consistency and disparity of genetic effects on risk of MI between Hispanic and white populations. The improvement in the identified genetic markers on discrimination of MI in Hispanics was modest.

Conventional and behavioral risk factors explain differences in sub-clinical vascular disease between black and Caucasian South Africans: the SABPA study

OBJECTIVES

There is an emerging burden of cardiovascular disease among urban black Africans in South Africa, which has been largely explained by the transition from traditional African lifestyles to more westernized behavior. We examined the role of health behaviors in explaining the excess burden of sub clinical vascular disease seen in black Africans compared to Caucasians.

METHODS

This was a cross-sectional study, comprising of urban African teachers (n=192 black, 206 Caucasian) working for one of the four Kenneth Kaunda Education districts in the North West Province, South Africa. Conventional cardiovascular risk factors, 24 h ambulatory blood pressure and objectively measured physical activity (Actical® accelerometers), smoking (confirmed by serum cotinine), and alcohol (serum gamma glutamyl transferase) were assessed. The main outcome was a marker of sub-clinical vascular disease, mean carotid intima media thickness (mCIMT), measured using high resolution ultrasound.

RESULTS

Compared with Caucasians, the black Africans demonstrated higher mCIMT (age and sex adjusted β=0.044, 95% CI, 0.024-0.064 mm). The blacks also had higher 24h systolic and diastolic blood pressure, triglycerides, adiposity, and C-reactive protein. In addition, blacks were less physically active (790.0 kcal/d vs 947.3 kcal/d, p<0.001), more likely to smoke (25% vs 16.3%, p=0.002), and demonstrated higher alcohol abuse (gamma glutamyl transferase, 66.6 μ/L vs 27.2 μ/L, p<0.001) compared with Caucasians. The difference in mCIMT between blacks and Caucasians was attenuated by 34% when conventional risk factors were added to the model and a further 18% when health behaviors were included.

CONCLUSION

There is an excess burden of sub clinical vascular disease seen in black Africans compared to Caucasians, which can be largely explained by health behaviors and conventional risk factors.

Hypertension in special populations: chronic kidney disease, organ transplant recipients, pregnancy, autonomic dysfunction, racial and ethnic populations

The benefits of appropriate blood pressure (BP) control include reductions in proteinuria and possibly a slowing of the progressive loss of kidney function. Overall, medication therapy to lower BP during pregnancy should be used mainly for maternal safety because of the lack of data to support an improvement in fetal outcome. The major goal of hypertension treatment in those with baroreceptor dysfunction is to avoid the precipitous, severe BP elevations that characteristically occur during emotional stimulation. The treatment of hypertension in African Americans optimally consists of comprehensive lifestyle modifications along with pharmacologic treatments, most often with combination, not single-drug, therapy.

Carotid intima-media thickness, dietary intake, and cardiovascular phenotypes in adolescents: relation to metabolic syndrome

Little is known about the interrelationships between metabolic syndrome (MS), uric acid, and early carotid atherosclerosis with diet in adolescents. We investigated associations among diet, carotid intima-media thickness (cIMT), MS, uric acid, and other cardiovascular risk factors in adolescents. Two hundred forty-nine adolescents from 3 high schools in Central California-a predominately Hispanic (n = 119, 16.1 +/- 0.9 years old, 94% Hispanic), a mixed-ethnicity (n = 94, 15.7 +/- 1.2 years old), and a Seventh-day Adventist (SDA) (n = 33, 17.0 +/- 1.3 years old) high school-were assessed for cIMT, blood lipids, uric acid, blood glucose, systolic and diastolic blood pressure, body mass index (BMI), and dietary intake. Compared with SDA adolescents, the predominately Hispanic and mixed-ethnicity high school adolescents exhibited higher low-density lipoprotein and BMI percentile, whereas adolescents from the SDA and mixed-ethnicity high schools exhibited lower uric acid and fasting glucose levels than those from the Hispanic high school. After adjusting for age and sex, cIMT was only correlated with systolic blood pressure percentile (r = 0.16, P < .01). Controlling for age, levels of uric acid were correlated with BMI percentile (males: r = 0.59, P < .001; females: r = 0.24, P < .01), low-density lipoprotein (males: r = 0.40, P < .001; females: r = 0.20, P < .01), and total cholesterol in males (r = 0.38, P < .001). Despite no significant differences in the high school frequency of MS risk factors, 59% of adolescents had one or more MS risk factors. A relationship was noted between the number of MS risk factors and uric acid (P < .002). Most of the adolescents presented MS risk factors independent of ethnicity or a purportedly healthier lifestyle (SDA). Uric acid association with MS and its risk factors suggests its potentially heightened importance for the assessment of adolescent cardiovascular health.

Ethnic differences in aortic valve thickness and related clinical factors

BACKGROUND

Prior studies suggest that the causes of calcific aortic valve (AV) disease involve chronic inflammation, lipoprotein levels, and calcium metabolism, all of which may differ among race-ethnic groups. We sought to determine whether AV thickness differs by race-ethnicity in a large multiethnic population-based cohort.

METHODS

The Northern Manhattan Study includes stroke-free community-based Hispanic (57%), non-Hispanic black (22%), and non-Hispanic white (21%) participants. The relation between AV thickness on transthoracic echocardiography and clinical risk factors for atherosclerosis was evaluated among 2,085 participants using polytomous logistic regression models. Aortic valve thickness was graded in 3 categories (normal, mild, and moderate/severe) based on leaflet thickening and calcification.

RESULTS

Mild AV thickness was present in 44.4% and moderate/severe thickness in 5.7% of the cohort, with the lowest frequency of moderate/severe thickness seen particularly among Hispanic women. In multivariate models adjusting for age, sex, race-ethnicity, body mass index, hypertension, coronary artery disease, blood glucose, and high-density lipoprotein cholesterol, Hispanics had significantly less moderate/severe AV thickness (odds ratio 0.43, 95% CI 0.25-0.73) than non-Hispanic whites. Men were almost 2-fold as likely to have moderate/severe AV thickness compared with women (odds ratio 1.96, 95% CI 1.24-3.10).

CONCLUSIONS

In this large multiethnic population-based cohort, there were ethnic differences in the degree of AV thickness. Hispanic ethnicity was strongly protective against AV thickness. This effect was not related to traditional risk factors, suggesting that unmeasured factors related to Hispanic ethnicity and AV thickness may be responsible.

Genetic ancestry is associated with subclinical cardiovascular disease in African-Americans and Hispanics from the multi-ethnic study of atherosclerosis

BACKGROUND

Differences in cardiovascular disease (CVD) burden exist among racial/ethnic groups in the United States, with African-Americans having the highest prevalence. Subclinical CVD measures have also been shown to differ by race or ethnicity. In the United States, there has been a significant intermixing among racial/ethnic groups creating admixed populations. Very little research exists on the relationship of genetic ancestry and subclinical CVD measures.

METHODS AND RESULTS

These associations were investigated in 712 black and 705 Hispanic participants from the Multi-Ethnic Study of Atherosclerosis candidate gene substudy. Individual ancestry was estimated from 199 genetic markers using STRUCTURE. Associations of ancestry and coronary artery calcium (CAC) and common and internal carotid intima media thickness were evaluated using log-binomial and linear regression models. Splines indicated linear associations of ancestry with subclinical CVD measures in African-Americans but presence of threshold effects in Hispanics. Among African-Americans, each SD increase in European ancestry was associated with an 8% (95% CI, 1.02 to 1.15; P=0.01) higher CAC prevalence. Each SD increase in European ancestry was also associated with a 2% (95% CI -3.4% to -0.5%, P=0.008) lower common carotid intima media thickness in African-Americans. Among Hispanics, the highest tertile of European ancestry was associated with a 34% higher CAC prevalence (P=0.02) when compared with the lowest tertile.

CONCLUSIONS

The linear association of ancestry and subclinical CVD suggests that genetic effects may be important in determining CAC and carotid intima media thickness among African-Americans. Our results also suggest that CAC and common carotid intima media thickness may be important phenotypes for further study with admixture mapping.

Screening for subclinical coronary artery disease measuring carotid intima media thickness

Traditional coronary risk assessment is based on major cardiovascular risk factors using the Framingham risk score. Carotid intima-media thickness (CIMT) measured by ultrasonography is a noninvasive test used to assess for the presence of coronary atherosclerosis. CIMT has been shown to be an independent predictor of future cardiovascular events and is used in research trials as a surrogate for the presence as well as regression of coronary artery disease. The objectives of this report are to review the published reports on CIMT and to help establish the role of CIMT as a screening tool for coronary artery disease in selected patients. CIMT measurement can modify cardiovascular risk prediction in patients initially classified with the Framingham risk score, with reclassification into higher or lower risk categories. It is most useful for refining risk assessment in patients at intermediate risk. The Screening for Heart Attack Prevention and Education (SHAPE) Task Force recommends screening all asymptomatic middle-aged and older men and women using noninvasive imaging. The American Society of Echocardiography established a consensus on the methodologic aspects of CIMT measurement. Sequential scanning of CIMT to assess atherosclerosis is currently not recommended, because of interscan variability and small expected changes over time. In conclusion, in the primary prevention of coronary artery disease, CIMT measurement reclassifies patients into higher or lower risk categories, allowing early appropriate management.

Carotid magnetic resonance imaging. A window to study atherosclerosis and identify high-risk plaques

Despite recent advances in the understanding and etiology of cardiovascular disease, it remains the leading cause of morbidity and mortality worldwide. A great deal of research has been dedicated to investigating and identifying plaque instability: the so-called "vulnerable plaque". A reliable, in vivo, imaging method capable of identifying plaque characteristics associated with high-risk plaque will be immensely useful for evaluating plaque status and predicting future events. With excellent soft-tissue contrast and resolution, magnetic resonance imaging (MRI) has the ability to visualize features of vulnerable plaques, as well as perform longitudinal studies on the etiology, progression, and regression of atherosclerotic plaque. This review will cover the current state-of-the-art and new developments in carotid MRI to characterize atherosclerosis and its use in clinical diagnoses and longitudinal studies to understand mechanisms of lesion progression and regression.

Single nucleotide polymorphisms in monocyte chemoattractant protein-1 and its receptor act synergistically to increase the risk of carotid atherosclerosis

BACKGROUND

Monocyte chemoattractant protein 1 (MCP-1), acting in concert with its receptor chemokine receptor 2 (CCR2), promotes recruitment of macrophages into atherosclerotic plaque. We examined whether single nucleotide polymorphism (SNP) variants in the MCP-1 or CCR2 genes independently or in combination are associated with carotid artery atherosclerosis in an African American population at increased risk of vascular disease.

METHODS

Four SNPs in MCP-1 and 1 in CCR2 were genotyped. Carotid artery duplex ultrasonography was used to identify the presence or absence of carotid plaque >1 mm. The study population included 325 apparently healthy 30- to 59-year-old black siblings of 185 probands with premature coronary artery disease (<60 years old). Associations between each independent SNP and the presence of carotid plaque were examined using multivariate logistic regression models adjusted for age, sex, educational level, diabetes, smoking, hypertension, obesity, low-density lipoprotein cholesterol and non-independence within families. Interactions between SNPs in the MCP-1 gene and the SNP in the CCR2 gene were examined by multivariate analysis.

RESULTS

Siblings were 32% males, with a mean age of 46 +/- 7 years, and 77 (24%) demonstrated carotid plaque. In multivariate analyses, the CC genotype of MCP-1 SNP rs2857656 was independently associated with plaque (p = 0.05). Subjects who had both the MCP-1 CC genotype and were heterozygotic or homozygotic for the CCR2 V64I genotype (rs1799864; n = 12) had an even higher risk of carotid atherosclerosis (odds ratio 6.14, 95% confidence interval 1.82-20.73; p = 0.0037).

CONCLUSION

The MCP-1 rs2857656 CC genotype is independently associated with carotid artery plaque in African American from families with premature coronary artery disease. The combination of the MCP-1 CC homozygous genotype and the homozygotic or heterozygote CCR2 V64I genotype is associated with a particularly high prevalence of carotid artery plaque.

Differences in subclinical cardiovascular disease between African American and Caucasian women with systemic lupus erythematosus

Racial differences exist in disease rates and mortality in both cardiovascular disease (CVD) and systemic lupus erythematosus (SLE). The objective of this cross-sectional study was to compare the frequency and risk factors for subclinical CVD in African American (AA) and Caucasian women with SLE and no prior CVD events. Traditional CVD risk factors and SLE-related factors were assessed in 309 SLE women. Subclinical CVD was assessed by carotid ultrasound to measure intimamedial thickness (IMT) and plaque, and electron beam computed tomography (EBCT) was used to measure coronary artery calcium (CAC). AA women had less education and higher levels of body mass index, blood pressure, lipoprotein(a), C-reactive protein (CRP), fibrinogen, and erythrocyte sedimentation rate (ESR). However, AA women had lower albumin, more and longer duration of corticosteroid use, higher SLE disease activity and damage, and more dsDNA antibodies compared with Caucasian women after adjustment for age and study site. More AA women had carotid plaque (adjusted odds ratio [OR], 1.94; 95% confidence interval [CI], 1.03-3.65) and higher carotid IMT (0.620 vs 0.605 mm, P = 0.07) but similar CAC compared with Caucasians. A multivariate analysis revealed that the following risk factor variables were significantly different between the racial groups and associated with plaque: blood pressure, current corticosteroid use, SLE disease activity, and SLE damage. All factors contributed to the result, but no individual risk factor fully accounted for the association between race and plaque. In conclusion, the presence of carotid plaque was higher in AA compared with Caucasian women with SLE, in contrast to studies of non-SLE subjects, in which AA have similar or less plaque than Caucasians. A combination of SLE-related and traditional CVD risk factors explained the racial difference in plaque burden.

Comparison of common carotid artery intima-media thickness between Brazilian Euro-descendants and Afro-descendants with atherosclerosis risk factors

OBJECTIVE

To compare common carotid intima-media thickness (IMT) between the two major Brazilian ethnic groups (those of African descent and those of European descent) among individuals with one or more risk factors for atherosclerotic disease.

METHOD

Two hundred and six patients with one or more risk factors for atherosclerotic disease were evaluated in a cross-sectional study in which their clinical, ethnic and Demographic characteristics were collected. All patients underwent duplex ultrasound examination of their carotid vessels to obtain IMT measurements.

RESULTS

One hundred and fifty-three patients (74.3%) had a carotid IMT greater than 1.0 mm at one or more point of measurement in at least one common carotid artery. There was a significant correlation between older age and mean carotid wall thickness (R=0.479 / P<0.01). Multivariate analysis identified male sex, arterial hypertension and older age as variables associated with increased IMT (P<0.05 for all variables). When IMT was compared between the two ethnic groups in this study, no significant differences were noted. Euro-descendants and Afro-descendants had similar IMT values, even when the groups were stratified by degree of IMT (normal vs. increased) and presence of stroke and/or transient ischemic attack (yes vs. no).

CONCLUSIONS

The risk factors associated with increased common carotid artery IMT in Brazilian individuals are similar to those in previously described populations. No differences were observed between the two main Brazilian ethnic groups. Longitudinal studies are required for a better evaluation of the incidence, etiologic factors and evolution of carotid intimomedial thickening in this population.