Ritu Jha –
Specks of calcium in the heart’s artery walls could be an early warning sign of early cardiovascular disease in South Asians, particularly men, according to a new study.
Alka Kanaya, a professor at UC San Francisco, told indica that while coronary artery calcium has been shown to be a good marker of hardening of the arteries in other ethnic groups, this is the first study that shows it to be true in South Asians, too.
“We wanted to see if the amount of CAC [coronary artery calcification] was higher in South Asians since the rates of heart disease appear to be higher in South Asians in many countries around the world,” Kanaya said.
She said that calcium is deposited in the walls of arteries that have cholesterol plaques in the later stage of atherosclerosis, the hardening of arteries. While there are soft cholesterol plaques in adolescents and young adults, the natural process of the body is to harden these plaques with a layer of calcium. The calcium is seen generally when people are in their fifties or older. Early signs of CAC show up in computed tomography (CT) scans.
The study, which appeared in the Journal of the American Heart Association, is among the findings generated by an ongoing study by Mediators of Atherosclerosis in South Asians Living in America (MASALA).
Led by Kanaya, MASALA is the first long-term study that aims to better understand the factors leading to heart disease and guide prevention and treatment in this population. Begun in 2010, it has enrolled South Asian immigrants living in the San Francisco Bay Area and the greater Chicago area, most of whom have spent decades in the United States.
She said that of the more than 1,164 people in the study, approximately 85 percent were born in India, about 6 percent in Pakistan, 1 percent each in Sri Lanka, Nepal, and Bangladesh, 2 percent in the US, with the remainder being born in various other countries. Those studied were between 40 and 84 years of age.
Kanaya said that the study hoped to explain the higher risk of heart disease and diabetes in this group, given that culture can play a role in disease. The research material from MASALA can be found at this website: https://www.masalastudy.org/publications/ )
“We have shown that stronger cultural beliefs are associated with thicker carotid arteries of the neck, regardless of other risk factors,” Kanaya said. “Thicker carotid wall arteries is also a risk factor for the development of stroke.”
Kanaya said that a lot of people should be on cholesterol-lowering medications (like statins) that have been shown to decrease the risk of heart disease. But many people may be taking these medications though they do not need to, she said.
The amount of coronary calcium seen in the CAC test can help determine those who have later stages of atherosclerosis and so should really be on a statin, and those who do not need to be on a statin (based on a CAC score of zero), Kanaya said.
The study shows also shows that South Asian men had a higher rate of new calcification than the women, 8.8 percent to 3.6 percent, respectively. After accounting for differences in age, diabetes, high blood pressure and statin use, increases in CAC in South Asian men were similar to those in white men but 122 percent, 64 percent and 54 percent larger respectively than in African American, Latino, and Chinese American men. There was no significant difference in the amount of CAC change among women in different race/ethnic groups.