The South Asian Cardiometabolic Curse: A High-Risk Population

South Asian ethnicity is included as a risk-enhancing factor for atherosclerotic cardiovascular disease (ASCVD) in the most recent Guideline on the Management of Blood Cholesterol.¹ “South Asian” refers to a diverse group of people from Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka. A higher prevalence of traditional risk factors combined with unhealthy lifestyle behaviors puts this population at a disproportionately high risk for cardiovascular disease.²

Dr. Anand Rohatgi discussed the risk of coronary disease in this population at the American Society of Preventive Cardiology 2023 Congress on CVD Prevention, referring to it as the “South Asian cardiometabolic curse.” South Asian people have a higher prevalence of insulin resistance, metabolic syndrome, and type 2 diabetes. That risk exists even in individuals with lower body-mass indices, a phenomenon known as “skinny fat,” which occurs when excess fat is present in those with normal body weights.

Dr. Rohatgi cited data from the UK Biobank that demonstrated a more than 2-fold-higher observed risk of ASCVD events in individuals of South Asian ancestry compared with those of European ancestry. Risk was not captured by the pooled cohort equations.³ Furthermore, in an analysis of the INTERHEART study, the population-attributable risk of elevated lipoprotein(a), or Lp(a), for myocardial infarction was highest in South Asian individuals compared with those of other ethnicities.⁴

Notable differences have also been described in coronary artery calcium (CAC), a marker of subclinical atherosclerosis, among South Asians compared with those of other ethnicities. In a study combining data from the MASALA and MESA cohorts, South Asian individuals had lower overall CAC volume but higher overall CAC density.⁵ Dr. Rohatgi suggested high-risk and noncalcified plaque on cardiac computed tomography angiography may be more important in South Asian individuals, but future investigations characterizing the epidemiology of coronary plaque are needed.

While traditional risk calculators do not take South Asian ethnicity into consideration, the QRISK calculator, which is derived from a UK population, incorporates South Asian ethnicity as a risk factor and may be a better tool for risk estimation; however, it does not adequately capture the higher risk.

Overall, the high burden of cardiovascular disease in South Asian individuals warrants increasing representation of these patients in clinical trials, as well as initiating community-based interventions to combat the “cardiometabolic curse.”

Dr. Gurleen Kaur is a resident at Brigham and Women’s Hospital and served as a CardioNerds Conference Scholar during the American Society of Preventive Cardiology 2023 Congress on CVD Prevention.

References

1. Grundy SM, Stone NJ, Bailey AL, et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation. 2019. doi:10.1161/CIR.0000000000000625
2. Volgman AS, Palaniappan LS, Aggarwal NT, et al. Atherosclerotic cardiovascular disease in South Asians in the United States: epidemiology, risk factors, and treatments: a scientific statement from the American Heart Association. Circulation. 2018. doi:10.1161/CIR.0000000000000580
3. Patel AP, Wang M, Kartoun U, Ng K, Khera, AV. Quantifying and understanding the higher risk of atherosclerotic cardiovascular disease among South Asian individuals: results from the UK Biobank prospective cohort study. Circulation. 2021;144(6):410-422. doi:10.1161/CIRCULATIONAHA.120.052430
4. Paré G, Çaku A, McQueen M, et al. Lipoprotein(a) levels and the risk of myocardial infarction among 7 ethnic groups. Circulation. 2019;139:1472-1482. doi:10.1161/CIRCULATIONAHA.118.034311
5. Rifai MA, Kanaya AM, Kandula NR, et al. Distribution of calcium volume, density, number, and type of coronary vessel with calcified plaque in South Asians in the US and other race/ethnic groups: the MASALA and MESA studies. Atherosclerosis. 2021;317:16-21. doi:10.1016/j.atherosclerosis.2020.12.003