Comparing coronary artery calcium among U.S. South Asians with four racial/ethnic groups: The MASALA and MESA studies
Introduction
Individuals of South Asian ancestry (from India, Pakistan, Bangladesh, Nepal, and Sri Lanka) represent a quarter of the world's population and are second fastest growing ethnic minority group in the United States [1]. South Asians have a high rate of coronary heart disease which cannot be fully explained by traditional cardiovascular risk factors [2], [3], [4]. In California, South Asians have the highest incidence of coronary heart disease [5] and highest heart disease mortality of any racial/ethnic group [6].
Coronary artery calcium (CAC) measurement is a non-invasive method for determining atherosclerosis burden [7] and has been recommended for further cardiovascular risk assessment amongst intermediate risk individuals [8], [9], [10]. While CAC scores differ by race/ethnicity [11], [12], a significant association between CAC score and incident coronary heart disease events has been reported in each of the race/ethnic groups studied in the Multi-Ethnic Study of Atherosclerosis (MESA) [13]. Few studies have examined the distribution of CAC score in asymptomatic South Asians [14], [15], [16], and no studies have determined whether CAC scores help explain the high incidence of heart disease in South Asians.
We sought to determine the prevalence, burden, and associations of CAC among a community-based sample of asymptomatic South Asians in the U.S. compared to the four other racial/ethnic groups in MESA. We used data from the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study which was modeled on MESA with similar protocols to allow for efficient cross-ethnic comparisons. We hypothesized that South Asian men and women would have higher overall CAC burden than other racial/ethnic groups.
Section snippets
Methods
The MASALA study is a community-based cohort of South Asian men and women from two clinical sites (San Francisco Bay Area at the University of California, San Francisco (UCSF) and the greater Chicago area at Northwestern University (NWU)). The baseline examination was conducted from October 2010 through March 2013. The institutional review boards of UCSF and NWU approved the MASALA study protocol.
The MASALA study methods and recruitment have been previously reported [17]. Briefly, to be
MESA study methods
The study design, eligibility and methods for MESA have been previously published [18]. MESA includes individuals from four racial/ethnic groups (Whites, African Americans, Latinos and Chinese Americans). We used data from the baseline MESA examination (2000–2002). Identical questionnaires for socio-demographic characteristics and physical activity and protocols for seated blood pressure, anthropometry and cardiac CT scanning were used as described above.
To have similar age range of
Statistical analyses
Baseline characteristics of the MASALA participants were compared to each of the MESA racial/ethnic groups using ANOVA for continuous variables and chi-squared tests of homogeneity for categorical variables. CAC scores were analyzed as a dichotomous outcome for any prevalent CAC, as a continuous outcome using ln(CAC+1), and as a categorical outcome. We compared the prevalence, mean, and distribution of CAC score categories between South Asians and the four MESA racial/ethnic groups using ANOVA
Results
The 803 South Asians between ages 44–83 enrolled in the MASALA study were on average five years younger than the MESA study participants. Table 1 shows the baseline characteristics by sex for each of the five racial/ethnic groups. Most South Asians (99%), Chinese (96%) and Latinos (69%) were born outside the U.S. South Asians had significantly higher socioeconomic attainment and lower current smoking rates than each of the MESA groups. South Asians had relatively lower BMI and waist
Discussion
In this cross-sectional comparison between U.S. South Asians and four other U.S. racial/ethnic groups without known cardiovascular disease, we found that South Asian men had similarly elevated prevalence of CAC compared to White men, while South Asian women had lower CAC prevalence than White women but similar to other race/ethnic minority groups in MESA. Mean CAC was similar between South Asian and White men over the age span and after full adjustment for covariates, and South Asian men had
Funding sources
The MASALA study was supported by the NIH grant no.1 R01 HL093009. Data collection at UCSF was also supported by NIH/NCRR UCSF-CTSI Grant Number UL1 RR024131. The MESA study was funded by contracts #N01-HC-95159, N01-HC-95169, N01-HC-95166 from the National Heart, Lung, and Blood Institute.
Disclosures
The authors have no conflicts of interest to disclose.
References (29)
- et al.
The relationship between metabolic risk factors and incident cardiovascular disease in Europeans, South Asians and African Caribbeans. SABRE (Southall and Brent revisited) – a prospective population based study
J Am Coll Cardiol
(2013) - et al.
Risk of coronary disease in the South Asian American population
J Am Coll Cardiol
(Aug 13 2013) - et al.
Coronary heart disease mortality for six ethnic groups in California, 1990–2000
Ann Epidemiol
(Aug 2004) - et al.
American College of Cardiology/American Heart Association Expert Consensus Document on electron-beam computed tomography for the diagnosis and prognosis of coronary artery disease
J Am Coll Cardiol
(Jul 2000) - et al.
Comparison of prevalence and severity of coronary calcium determined by electron beam tomography among various ethnic groups
Am J Cardiol
(May 15 2003) - et al.
Prevalence of coronary artery calcium scores and silent myocardial ischaemia was similar in Indian Asians and European whites in a cross-sectional study of asymptomatic subjects from a U.K. population (LOLIPOP-IPC)
J Nucl Cardiol
(May 2011) - et al.
Aggressive and diffuse coronary calcification in South Asian angina patients compared to Caucasians with similar risk factors
Int J Cardiol
(Sep 10 2013) - et al.
South Asian men have different patterns of coronary artery disease when compared with European men
Int J Cardiol
(Oct 13 2008) - et al.
Coronary artery diameter as a risk factor for acute coronary syndromes in Asian-Indians
Am J Cardiol
(Sep 15 2005) 2010 census–demographic profile data
(2010)
Ethnic differences in mortality from ischaemic heart disease and cerebrovascular disease in England and Wales
Brit Med J
Mortality from coronary heart disease in Asian communities in London
Brit Med J
ACCF/AHA 2007 clinical expert consensus document on coronary artery calcium scoring by computed tomography in global cardiovascular risk assessment and in evaluation of patients with chest pain: a report of the American College of Cardiology Foundation Clinical Expert Consensus Task Force (ACCF/AHA Writing Committee to Update the 2000 Expert Consensus Document on Electron Beam Computed Tomography)
Circulation
Assessment of coronary artery disease by cardiac computed tomography: a scientific statement from the American Heart Association Committee on Cardiovascular Imaging and Intervention, Council on Cardiovascular Radiology and Intervention, and Committee on Cardiac Imaging, Council on Clinical Cardiology
Circulation
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