The incidence and progression rates of coronary artery calcium (CAC) on the CT scans of South Asian men living in the U.S. were as high as those of whites and markedly higher than those of black, Chinese, and Latino men, according to an article published online January 11 in the Journal of the American Heart Association.
The group, led by first author Dr. Alka Kanaya from the University of California, San Francisco (UCSF), acquired the calcium scores of approximately 700 individuals who underwent initial CT scans and a follow-up exam five years later as part of the ongoing Mediators of Atherosclerosis in South Asians Living in America (MASALA) study, first begun in 2010. The population consisted of men and women from India, Pakistan, Bangladesh, and other South Asian countries who now live in the U.S.
After controlling for traditional cardiovascular risk factors, the researchers found that South Asian men living in the U.S. had similar calcium scores to those of white men but considerably higher scores than other racial and ethnic minorities, including black, Chinese, and Latino men. The percentage increase in calcium scores for the South Asian men, between the initial and follow-up CT exam, was 122% larger than it was for black men, 64% larger than it was for Latino men, and 54% larger than it was for Chinese men.
The annual rate of new calcification in the South Asian men was 8.8%, compared with only 3.6% in South Asian women. There were no statistically significant differences in calcium score between the South Asian women and those from other racial and ethnic groups.
"Both CAC burden and progression have been shown to be independent predictors of coronary heart disease in whites, blacks, Latinos, and Chinese Americans," Kanaya said in a statement. "The next step for us is to determine if CAC burden and/or progression predicts those at highest risk of having a heart attack or stroke among South Asians."
