New risk factors of heart disease among Indians
Increased incidence of coronary artery disease among Indians, including those residing abroad, needs an understanding of basic mechanisms involved in the predisposition to increased morbidity and mortality. Studies have shown that high incidence of heart disease among Indians it accompanied by a paradoxically low prevalence of conventional risk factors such as hypertension, smoking, hypercholesterolemia, etc.
The newly emerging risk factors responsible for early and increased prevalence of heart disease need to be understood. Several studies have shown that Lp (a), an LDL particle (bad cholesterol) with apo lipoprotein (a) attached to lipoprotein B, is an independent risk factor for premature heart disease. The levels of Lp (a) are genetically determined. It interferes with the process related to the thrombosis- thrombolysis. It inhibits fibrinolytic system and creates a pro thrombotic state. Serum levels of Lp (a) correlates with the occurrence and the recurrence of myocardial infarct and cardiac death. It is recognised as biological marker for familiar heart disease. The coronary disease in Indian study (CADD) has reported the existence of high levels of Lp (a) among Indians. In a study of 1150 subjects involving seven ethnic groups, Lp (a) levels were regularly twice as high in Asian Indians as compared to Caucasians. Elevated levels of Lp (a) can be reduced by medicines and plasma LDL apheresis but not by life style changes or statins.
In Indian patients with coronary artery disease, high triglycerides (hypertriglyceridemia) are found more often than high cholesterol levels. Triglycerides bring changes in LDL particle size, density, distribution and composition producing smaller dense and more etherogenic particles. It’s not clearly confirmed whether isolated lowering of triglycerides can reduce morbidity and mortality in coronary artery disease.
As people all around the globe are in grip of obesity and overweight syndromes, Indians are among those badly affected cohorts.
Comparatively, Indians have more bad fat for the same weight and height than European and North Americans. They become insulin resistant at less weight. This insulin resistant leads to variety of illnesses including diabetes and coronary artery disease. One of the efficient treatments for this malady is through weight reduction and physical activity.
Smaller the LDL particles (bad cholesterol) bigger the risk of coronary artery disease! It has been observed that Asians have 74 percent prevalence of phenotype B (LDL subclass) as compared to 24 percent among white population. This makes them have more small dense LDL particles, making them more prone to heart diseases.
Abnormally high level of homocysteine in the blood causes hyperhomocysteinemia. And homocysteine is a sulphur containing amino acid formed during the metabolism of methionine. Mild to moderate alleviation of plasma homocysteine levels are due to nutritional deficiency involving folate, vitamin B6 and vitamin B12. Constant lowering of homocysteine levels eventually helps in preventing coronary artery disease.
Infections & inflammatory markers
Various viral and bacterial infections have been implicated in atherosclerosis among all chlamydia pneumonia, which is considered to be an important risk factor for myocardial infarction and unstable angina. Alert for these infections may be important in the developing countries like India. High levels of C reactive proteins are related to the presence of inflammation that may associate with increased risk of heart diseases.
Yet another risk factor is thrombosis or formation of blood clot as elevated level of fibrinogens (that helps in the formation of blood clots) is an independent risk factor for heart disease. Fibrinogen increases blood viscosity and leads to thrombosis. Smoking cessation, fibrate therapy, estrogen replacement and leisure time physical activity are helping in reducing fibrinogen levels.
There is inverse relationship between height of a person and risk of getting coronary artery disease.
For every 2.5 inch in height affects your risk of coronary artery disease by 13.5 percent. For example, compared to persons of 5.6 ft, those in an average height of 5 ft have 32 percent higher risk of getting coronary artery disease because of their physical stature. Individual response to stress may also play a major contributing factor to heart diseases. Some scientists have noted relationship between coronary artery disease and factors including stress in a person’s life, health behaviour and socio-economic status.
Alcohol is yet another factor for heart disease, if consumed more than in moderation. Too much alcohol can raise blood pressure, causing heart failure and that can even lead to stroke. It can also contribute to high triglyceride, cancer and other general health conditions including obesity, alcoholism and accidents. If you drink, limit your alcohol to not more than two drinks per day for men and one drink for women. Heart diseases have inverse association with vitamin D. General notion of using vitamin D supplementation to reduce risk of heart disease remains controversial as large scale trials are now under way to get final conclusions. On the other side, there are certain medical conditions that contribute to heart disease, which include end-stage renal failure, chronic inflammatory disease affecting the connecting tissues, HIV-AIDS and xanthelasmata (yellow patches over the eyelids).
Diet and nutrition
A healthy diet is the best weapon to fight heart disease. The food you eat can affect other controllable risk factors, cholesterol, blood pressure, diabetes and overweight. Choose nutritious foods containing vitamins, fibers, minerals and other nutrition with low calories. A diet rich in vegetables, fruits, whole grain, high fiber foods, fish, lean protein, and fat free or low fat dairy products is the key. Maintain healthy weight and coordinate your diet with your physical activity levels so that you can burn up as many calories as you take. Let your heart beat to the healthiest!
Dr Narottam Bhardwaj completed MBBS in 1973 and MD in Medicine in 1978 from Maulana Azad Medical College, University of Delhi. He worked for three years in LNJP and GB Pant Hospitals, New Delhi from 1982. He has been in private practice as a consultant physician to various hospitals like Indraprastha Apollo Hospital, etc. At present he is senior consultant- Internal Medicine at Max Hospital, Saket, Sukhda Hospital, New Delhi. He is also Medical Advisor to Power Grid Corporation, Power Finance Corporation and SIEMENS. He has published several papers on diabetes, hypertension and heart disease. He has special interest in diabetes. He is a member of Delhi Medical Association and American Diabetic Association.