Authored by Amina Khan
Art by Daisy Meng
“As a primary care physician, I would see young South Asians coming in who’d had a heart attack,” said Dr. Kandula, founder of the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study [1]. Interestingly, Kandula and other researchers found that people of South Asian ancestry did not necessarily fit the typical risk factor profile. Individuals of South Asian background (from India, Pakistan, the Maldives, Nepal, Bangladesh, Bhutan, and Sri Lanka) who migrate to North America or Europe seem to have an elevated risk for atherosclerotic cardiovascular disease (ASCVD) compared to non-Hispanic White and other Asian-American groups [3]. At MASALA, the question of whether any biological variance related to ancestry predisposes the South Asian population has garnered significant interest and remains an active area of research.
Taking a deeper look at disease incidence, South Asian Americans experience a higher proportion of mortality and higher burden of premature mortality from ASCVD. Furthermore, South Asian adults have a higher prevalence of cardiovascular risk factors type II diabetes and hypertriglyceridemia, and greater levels of ectopic fat compared with non-Hispanic White adults [3]. South Asian adults with hypertension are also younger, more likely to be male, and have lower mean BMI than non-Hispanic White adults. Additionally, South Asians are more likely to deposit extra fat in organs like the liver, inside muscle tissue, and around the abdominal visceral organs rather than depositing it under the skin [1].
A combination of varying sociocultural, behavioral and lifestyle factors related to ethnicity and regional association come into play when understanding the difference in disease prevalence. Dietary and nutrition patterns, physical activity levels, healthcare access, language barriers, and socioeconomic position only begin to explain this phenomenon [6]. In regards to preventative health, the public statement of the risk factors of hypertension and dyslipidemia has led to an increase in education, empowerment, and change in the South Asian community. For instance, when hypertension was first determined to be a risk factor for ASCVD, increased awareness surrounding lifestyle modifications was raised and led to novel drug developments over the years [5]. Furthermore, South Asian ancestry was added in the cholesterol guidelines as a risk enhancer for ASCVD (American College of Cardiology). However, skeptics like Dr. Jaideep Patel, a cardiology fellow at the Virginia Commonwealth University Medical Center, claim that despite preventative health campaigns such as AHA’s Life Simple 7, Go Red for Women/Go Red Sari, and national prevention guidelines, which reinforce healthier lifestyles, higher prevalence of ASCVD still remains in these populations [2]. Therefore, modifiable risk factors can only partly explain this disparity.
In studying the potential genetic predisposition to cardiovascular disease, data revealed a polymorphism in the patatin-like phospholipase domain-containing protein-3 (PNPLA3) gene which has been found to be associated with non-alcoholic fatty liver disease, a cardiovascular disease risk factor [7]. Variation in PNPLA3 genotype can also determine insulin sensitivity, which can contribute to the onset of diabetes from a prediabetic state and hence plays a role in development of ASCVD [5]. From a dyslipidemia causality perspective, genes such as LDR, APO C3, LPA, and others may be upregulated in the South Asian population, further contributing to ASCVD prevalence [5]. Other studies have focused on the modification or dysregulation of metabolites and their correlation to ASCVD risk [4]. A metabolomics study of 145 South Asian Indians revealed that the metabolite pattern of aromatic amino acids, branched-chain amino acids, and short-chain acylcarnitines, which display a nonvegetarian diet, was associated with adverse cardiometabolic profile [4].
In conclusion, further research is likely to increase awareness but may also create uneasiness in the South Asian community. It is important to clarify that South Asian ancestry is not a modifiable risk factor. However, modifiable risk factors are more prevalent in this population and should be investigated and treated. Following leadership at American Heart Association, National Lipid Association, and American College of Cardiology, this knowledge can help individuals modify their lifestyle to reduce the risk of cardiovascular disease and recognize symptoms, ensuring prompt medical attention. Proactive intervention, risk assessment, and positive reinforcement are critical clinical strategies that must be employed to effectively reduce the burden of ASCVD disease in the South Asian population [5]. From a medical perspective, this decision offers an opportunity to research biomarkers of risk earlier in SA patients and innovate new treatments.
Works Cited
Abbasi, J. Masala Study Probes Why People With South Asian Ancestry Have Increased Cardiovascular Disease Risks. (2022). Jama Network. 328(6):511-514. doi:10.1001/jama.2022.11417.
Patel, J. (2021). South Asian cardiovascular disease: Dispelling stereotypes and disparity. American Journal of Preventive Cardiology, vol. 7, 2021, p. 100189, https://doi.org/10.1016/j.ajpc.2021.100189.
Reddy, N., Kaushal, V., Kanaya, A., Kandula, N., Gujral, U., Shah, N. (2021). Cardiovascular Risk factor profiles in North and South Indian and Pakistani Americans: The MASALA Study. American Heart Journal, Vol. 244, 2022, pp. 14–18, https://doi.org/10.1016/j.ahj.2021.10.115.
Sun, Y., Liu, C., Staimez, L., Ali, M., Chang, H., Kondal, D., Patel, S., Jones, D., Mohan, V., Tandon, N., Prabhakaran, D., Quyyumi, A., Narayan, V., Agrawal, A., (2021). Cardiovascular disease risk and pathophysiology in South Asians: can longitudinal multi-omics shed light? Wellcome Open Research, vol. 5, 2020, p. 255, https://doi.org/10.12688/wellcomeopenres.16336.1.
Vijayaraghavan, K. (2019). South Asian ancestry as a risk enhancer for ASCVD: Merits and challenges. Journal of Clinical Lipidology, vol. 13, no. 4, 2019, pp. 522–524, https://doi.org/10.1016/j.jacl.2019.04.009.
Volgman, A., Palaniappan, L., Aggarwal, N., Gupta, M., Khandelwal, A., Krishnan, A., Lichtman, J., Laxmi, M., Patel, H., Shah, K., Shah, S., Watson, K., (2018). Atherosclerotic Cardiovascular Disease in South Asians in the United States: Epidemiology, Risk Factors, and Treatments: A scientific statement from the American Heart Association. Circulation, vol. 138, no. 5, 2018, https://doi.org/10.1161/cir.0000000000000600.
Wolf, R., Nagpal, M., Magge, S., (2020). Diabetes and Cardiometabolic Risk in South Asian Youth: A Review. Pediatric Diabetes, vol. 22, no. 1, 2020, pp. 52–66, https://doi.org/10.1111/pedi.13078.