To battle the epidemic of south Asian heart disease current literature calls for all south Asians over the age of 25 years to begin routine screening with a traditional blood cholesterol (lipid) panel. However what is not common knowledge is that there are a few additional blood tests available, not included in most standard lipid panels, that may provide important additional information about a south Asian’s risk of developing cardiovascular disease. A traditional cholesterol panel include:
Total Cholesterol (TC), Low Density Lipoprotein (LDL), High Density Liprotein ( HDL) and Triglycerides ( TRG).
Ideal levels of these tests for south Asians are published in the South Asian Heart Disease Guidelines. While these data are very important and often sufficient to guide physicians on which patients should be started on cholesterol reducing drugs ( i.e. statins, niacin, fibrates, etc), for south Asians additional blood tests ( or biomarkers) may be obtained to better guide risk management. These biomarkers are associated with a complex multi-step process leading to the development of diffuse plaque buildup known as “Atherosclerosis“. Given south Asians have the highest proportion of heart disease compared to any other ethnicity, additional testing of such biomarkers may be indicated and worth further discussion with your physician.
IMPORTANT BIOMARKERS TO CONSIDER IN EVERY SOUTH ASIAN’S LIPID PANEL:
1. LIPOPROTEIN A, Lp(a): Normal value is < 20mg/dL. Lp(a) is a circulating protein that resembles LDL cholesterol but also consists of another glycoprotein called “Apo( a) “. Many studies have shown elevated Lp(a) levels to correlate with future cardiovascular events (i.e. heart attacks). Currently there is no drug that directly reduces Lp(a). Elevated Lp(a) levels may identify south Asians in need of more aggressive lifestyle and cholesterol reducing therapy.
2. HIGH SENSITIVITY C-Reactive Protein (hs-CRP): Normal value is < 3mg/L. CRP is a systemic inflammatory marker widely studied and proven to be a predictor of cardiovascular events in otherwise asymptomatic patients. It has been particularly found in South Asians to correlate with metabolic syndrome (a condition that leads to diabetes and heart disease). Elevated CRP may suggest south Asians in need of more aggressive lifestyle and cholesterol reducing therapy.
3. LDL PARTICLE SIZE: “The Bigger the Better” LDL cholesterol differs in size and density. There is the small and dense pattern vs. the large and non-dense pattern. The small and dense LDL cholesterol is associated with higher rates of cardiovascular events (i.e. heart attacks). It is also found with metabolic syndrome, diabetes, high triglycerides and lower HDL cholesterol levels. Small and dense LDL cholesterol may suggest south Asians in need of more aggressive lifestyle and cholesterol reducing therapy.
4. HOMOCYSTEINE: Normal value is < 13mmoL/L. Homoscysteine is a an amino acid. There is mixed data regarding its efficacy as a heart disease biomarker. Several studies have linked elevated homocysteine levels to heart disease, however other studies have found no correlation. Therefore at present time an elevated level of homocysteine may or may indicate the need for more aggressive lifestyle and cholesterol reducing therapy.
As members of the south Asian community we have all heard frightening stories about 30 something, 40 something year old men and women developing heart disease. Whether its discovered by going the emergency room for severe chest pain or by routine doctor’s visit; its prevalence is growing. I recently came cross Mr. “P”, a 37 year old lawyer born and raised in India who developed chest pressure while sitting in his NYC midtown office. He was diagnosed with a NSTEMI ( non-ST segment myocardial infarction). His cardiac catheterization revealed diffuse multi-vessel coronary artery disease!!! His arteries were similar to those of a 80 year old, not 37.
Afterwards he asked me,” Doctor. how could this happen, ..I exercise, control my diet, watch my cholesterol, aren’t I too young for a heart attack?” Current research has still yet to clearly discover one specific mechanism, but there are certain modifiable risk factors that pre-dispose Mr. “P” to heart disease. However obesity, metabolic syndrome and diabetes are major cardiovascular risk factors among South Asians, that are also influenced by genetic and environmental predispositions. Many of the risk factors for CAD, particularly diabetes and metabolic syndrome, are preventable. Public awareness and prevention of these risk factors must be a priority among the medical community.
Doctors at Mt. Sinai Hospital published a new study in “Ethnicity & Disease” that Compares Hearts of Immigrant South Asians to Caucasions which raises awareness and concern to the on going battle against heart disease in the South Asian community. Dr. Silbiger and collegues critically reviewed cardiac risk factors and angiograms of 520 South Asians and 219 Caucasians consecutively referred with stable angina or acute coronary syndrome and found South Asians are younger, have significantly higher rates of 3-vessel disease, as well as higher rates of diabetes, hypertension, obesity and dyslipidemia than Caucasians.
Even with a modest enrollment size, its findings are as would be expected. This report adds to the mounting literature from all over the world further illustrating the rising epidemic of heart disease among South Asians. The current US heart disease prevention model, largely influenced by the Framingham database and its 10- year cardiovascular risk score fails to account for such discrepancies in South Asian ethnicity as illustrated in this study.
Article Link: Coronary artery disease in South Asian immigrants living in New York City: angiographic findings and risk factor burdens. While the findings here are important to the field, there are many questions remaining to be answered. For instance, do immigrants carry a different risk than say 1st generation south Asians raised in the US? What role does diet and enviroment play in each group?
Thank you for your attention. Visit www.southasianhealthyliving.com for more information on South Asian Heart Disease.