Underestimation of Heart Disease Risk in South Asians in the UK
- The high rate of CAD (coronary artery disease) among South Asians is accompanied by similar or lower levels of traditional risk factors with the exception of diabetes.
- Normal ranges for independent risk factors for CAD (such as blood pressure, lipid profile, body mass index, and waist circumference) derived from studies on Western populations may be set too high for south Asians. Interventions driven by these ranges may therefore result in under-treatment.
- All major risk prediction tools including Framingham risk score, Finland Cardiovascular Risk (FINRISK), and Systematic Coronary Risk Evaluation (SCORE) grossly underestimate CAD risk in South Asians.1
- A recent analysis of data from the Health Survey for England in 1998 and 1999 was conducted to identify a simple method for adjusting the Framingham equation to estimate coronary risk in South Asians.
- Adding 50mm Hg for blood pressure or 108mg/dl for cholesterol was found to provide reasonable accuracy. However adding 10 years to the age of south Asian people was found to be the simplest way of calculating CAD risk while still providing acceptable accuracy.2
- Although the UK provides comprehensive medical care to all her subjects, the risk of dying from heart disease is more than double among South Asian men even after accounting for the differences in the level of traditional risk factors (age, smoking, blood pressure, cholesterol, metabolic syndrome, diabetes, and socioeconomic status). (Figure 030)3
- There is thus an urgent need for guidelines to be developed that are specifically tailored to the South Asian population. For these reasons, treatment guidelines in UK, Europe, and Australia have specific modifications that mandate treatment of Asian Indians with medications at a lower level of risk factor levels/threshold than whites.4, 5
- The Indo-US health summit has also proposed lower set of thresholds for risk factors for Indians for countries that do not have specific modifications for treatment guidelines.5
Sources
1. Bhopal R, Fischbacher C, Vartiainen E, Unwin N, White M, Alberti G. Predicted and observed cardiovascular disease in South Asians: application of FINRISK, Framingham and SCORE models to Newcastle Heart Project data. J Public Health (Oxf). Mar 2005;27(1):93-100.
2. Aarabi M, Jackson PR. Predicting coronary risk in UK South Asians: an adjustment method for Framingham-based tools. Eur J Cardiovasc Prev Rehabil. Feb 2005;12(1):46-51.
3. Forouhi NG, Sattar N, Tillin T, McKeigue PM, Chaturvedi N. Do known risk factors explain the higher coronary heart disease mortality in South Asian compared with European men? Prospective follow-up of the Southall and Brent studies, UK. Diabetologia. Nov 2006;49(11):2580-2588.
4. Graham I, Atar D, Borch-Johnsen K, Boysen G, Durrington PN. European guidelines on cardiovascular disease prevention in clinical practice: executive summary: Fourth Joint Task Force of the European Society of Cardiology and Other Societies on Cardiovascular Disease Prevention in Clinical Practice (Constituted by representatives of nine societies and by invited experts). Eur Heart J. Oct 2007;28(19):2375-2414.
5. Enas EA, Singh V, Gupta R, Patel R, et al. Recommendations of the Second Indo-US Health Summit for the prevention and control of cardiovascular disease among Asian Indians. Indian heart journal. 2009;61:265-74.