Cardiovascular disease in India and the impact of lifestyle and food habits

Dr Rajesh Pande

Cardiovascular disease is the world's leading killer, accounting for 16.7 million or 29.2 per cent of total global deaths in 2003. With modernization, a large proportion of Asians are trading healthy traditional diets for fatty foods, physical jobs for deskbound sloth, the relative calm of the countryside for the stressful city. Heart-attack victims are just the first wave of a swelling population of Asians with heart problems. While deaths from heart attacks have declined more than 50 per cent since the 1960s in many industrialize countries, 80 per cent of global cardiovascular diseases related deaths now occur in low and middle-income nations, which covers most countries in Asia.

In India in the past five decades, rates of coronary disease among urban populations have risen from 4 per cent to 11 per cent. In urban China, the death rate from coronary disease rose by 53.4 per cent from 1988 to 1996. A report released last week by the Earth Institute at Columbia University warned that without sustained effort on individual and national levels, the coming heart-disease epidemic will exact a devastating price on the region's physical and economic health. In Professor Philip Poole-Wilson, president of the World Heart Federation words. "We're trying to warn people sufficiently early so that they can do something about it, but this isn't a disease you can cure by turning on an electric switch."

The World Health Organization (who) estimates that 60 per cent of the world's cardiac patients will be Indian by 2010. Dr Timothy Gill, an Asia-Pacific specialist with the International Obesity Task Force, a medical NGO that coordinates with the WHO on obesity issues feels that of all Asians, South Asians have by far the worst problems when it comes to heart disease. Nearly 50 per cent of CVD-related deaths in India occur below the age of 70, compared with just 22 per cent in the West. This trend is particularly alarming because of its potential impact on one of Asia's fastest-growing economies. In 2000, for example, India lost more than five times as many years of economically productive life to cardiovascular disease than did the U.S., where most of those killed by heart disease are above retirement age.

Studies indicate that South Asians have elevated levels of LDL cholesterol and triglycerides, while also suffering from a deficiency in HDL cholesterol (good cholesterol, which helps clear fatty buildups from blood vessels). In addition, South Asians tend to gain weight in the abdominal region (Waist: hip ratio >1.0 in men, >0.9 in women) and are at greater risk of heart disease. Environmental factor like low birth weight, malnutrition also possibly predisposes Indians to increased risk of diabetes and heart attacks in adulthood.

Statistics suggest that South Asians seem more naturally vulnerable to heart disease than other ethnic groups. Lancet 2000 study showed that, even after adjusting for all known risk factors; South Asians in Canada appeared to have a higher rate of heart disease than Europeans or Chinese living there. Some doctors think that this vulnerability can be explained by the "thrifty-gene" theory, which holds that South Asians adapted over many generations to the region's frequent famines. Now with a very recent overabundance of food, their bodies are having difficulty making a metabolic U-turn and the result is high insulin intolerance, with accompanying raised levels of diabetes and obesity.

The 10 leading selected risk factors for death and disability, by type of country as given by WHO:

Some new markers have been identified: Nearly 95 percent of people who developed a fatal cardiovascular disease had at least one of these major risk factors: high blood cholesterol, high blood pressure, smoking, diabetes besides a poor diet and overweight. But it can also develop in the absence of any traditional risk factors and evidence is accumulating that several other risk factors may help predict or contribute to cardiovascular disease.

Among the leading new potential culprits: C-reactive protein (CRP), Homocysteine, Fibrinogen, Lipoprotein (a). Information about how these four substances are connected to cardiovascular disease is still emerging, and researchers continue to debate their importance. Indeed, there's much to be learned before screening for these substances becomes as routine as getting the blood pressure or cholesterol checked. Routine screening of the general public for these markers is not recommended but there may be a role for screening in people who have a strong family history of cardiovascular disease, have early onset disease with no apparent traditional risk factors, or whose disease isn't well controlled despite optimal management of traditional risk factors. It's not clear yet what role these four substances play in predicting or causing disease and testing for these substances isn't fully standardized. There is hope that they may help lead to additional prevention and treatment strategies for cardiovascular disease.

C-reactive protein : (CRP) is a protein produced by the liver as part of the normal immune system response to injury or infection. CRP is an inflammatory marker and inflammation has a central role in atherosclerosis the accumulation of plaques of fats, cholesterol and other material in the arteries. High levels of CRP in the blood have been associated with an increased risk of cardiovascular disease, including heart attack and stroke. But it's not clear if CRP actually causes heart disease or is just a sign of inflammation, which may cause heart disease. The AHA and the Centers for Disease Control and Prevention recommend CRP screening for an intermediate risk a 10 percent to 20 percent chance of developing coronary heart disease in the next 10 years. Low risk: Less than 1 mg/L, Average risk: 1 to 3 mg/L, High risk: Over 3 mg/L. If the CRP is greater than 10 mg/L, it's likely the result of an infection or other condition and isn't useful in assessing the cardiovascular risk and the test should be repeated in about two weeks, or after the infection is gone, to assess cardiovascular risk.

Homocysteine: It is an amino acid normally present in the blood and is utilized by the body to make protein and to build and maintain tissue. Studies indicate a link between high plasma levels of homocysteine and an increased risk of stroke, certain types of heart disease, and peripheral vascular disease. Raised levels may be associated with four times higher risk than normal homocysteine levels. The exact mechanism of its action isn't clear and as with CRP, it's not known if homocysteine is a cause of cardiovascular disease or a marker of its presence. Recent work suggests that increased homocysteine levels may eventually cause the tissues lining arteries to thicken and scar. Cholesterol can build up in those scarred areas, providing a surface for blood clots to form. There's no consensus on what homocysteine levels are optimal, but in general, less than 12 micromoles is desirable. Readings in healthy people can range between 5 and 15 micromoles. Elevated homocysteine levels can be decreased by dietary supplementation of folate, vitamin B.

Fibrinogen: Although fibrinogen is needed for normal blood clotting, its excess may promote excessive clumping of platelets and can result in thrombosis in an artery, leading to a heart attack or stroke. Besides inactivity, excessive alcohol consumption and estrogens, whether from birth control pills or hormone therapy, which elevate fibrinogen, smoking is the most significant lifestyle factor that raises fibrinogen levels. The normal range for blood (serum) fibrinogen is 200 to 400 mg/dL, and levels around 400 mg/dL is associated with a twofold increase in risk of heart attack or stroke.

Lipoprotein(a): It's formed when a low-density lipoprotein (LDL) cholesterol particle attaches to a specific protein. Studies show that an increased level of Lp(a) is associated with an increased risk of cardiovascular complications, including early coronary heart disease, heart attack and stroke. Elevated Lp(a) level, generally do not respond to most lipid lowering agents but niacin, omega-3 fatty acids or estrogen may help in some cases.

Deaths from cardiovascular diseases, principally acute myocardial infarction and cerebrovascular accidents, have decreased substantially over the past two decades, largely as a result of advances in acute care and cardiac surgery, aggressive antihypertensive therapy, the recognition of the hazards of tobacco abuse, improved nutritional patterns coupled with a decrease in cholesterol values in the general population, and an increased emphasis on physical activity.

However, these developments have produced a growing population of patients who have survived a myocardial infarction or who have a stable, if not controlled, pattern of angina pectoris due to atherosclerotic coronary artery disease. These patients, and those with peripheral vascular disease, hypertension, hyperlipidemia, diabetes mellitus, and chronic obstructive pulmonary disease, are potential participants and likely benefactors of heart smart strategies that include change in dietary habits and cardiac-rehabilitation programs. These techniques are particularly useful in the Indian context where the semi urban and rural population is largely unaware about the importance of lifestyle techniques in prevention of cardiovascular disease.

Cardiac rehabilitation is a medically supervised exercise and counseling program designed to help overcome some of the physical complications of heart disease, limit the risk of developing additional heart trouble, help a person return to an active social or work schedule, and improve the psychological well-being. It has four main components: Medical evaluation, supervised exercise, lifestyle education and psychosocial support. Cardiac rehabilitation takes time at least six months and it's not always easy. It's also not suited for everyone with a heart problem, and the results may vary for reasons beyond the participant's control.

But for most people in cardiac rehab, the hard work put into it offers many rewards. Participation maximizes their ability to regain independence and provides the knowledge to ensure that healthy living will become a permanent part of their future.

Five heart-smart strategies directed towards healthy dietary habits.

1.Limit intake of unhealthy fats and cholesterol

The best way to cut saturated and trans fat intake is to limit the amount of solid fat like butter, margarine that is added to food when cooking and serving. If fat is to be used, choose oils high in monounsaturated fat, such as olive oil or canola oil. Avoid butter, lard, bacon, gravy, cream sauce, nondairy creamers, hydrogenated margarine, cocoa butter found in chocolate, coconut, palm and palm kernel oils.

Use of monounsaturated fats lower the total cholesterol and low-density lipoprotein (LDL) cholesterol (the "bad" cholesterol).

2. Choose low-fat protein sources

Although meat, poultry and fish along with dairy products and eggs are some of the best sources of protein, they are high in total fat, saturated fat and cholesterol. Skim milk rather than whole milk or skinless chicken breast rather than fried chicken patties are lower fat versions and may be substituted for the above. Fish is another good alternative to high-fat meats. Some types of fish such as cod, tuna have less total fat, saturated fat and cholesterol than do meat and poultry whereas certain types of fish like salmon, mackerel and herring are heart healthy because they're rich in omega-3 fatty acids. These fats may help lower triglyceride levels and may reduce the risk of sudden cardiac death.

Legumes like beans, peas and lentils are good sources of protein and contain less fat and no cholesterol, making them good substitutes for meat. Soybeans may be especially beneficial to the heart and may be regularly substituted for animal protein.

3. Eat more fruits and vegetables

Fruits and vegetables are low in calories, good sources of vitamins and minerals, and rich in dietary fiber. They also contain phytochemicals, substances found in plants that may help prevent cardiovascular disease. Eating more fruits and vegetables helps us indirectly also by satisfying hunger and thereby reducing intake of high-fat foods. Don't smother vegetables in butter, dressings, creamy sauces or other high-fat garnishes. Avoid fruits in cream or heavy sauces.

4. Select whole grains

Whole grains do not have their bran and germ removed by milling, making them good sources of fiber, which the body can't digest besides other nutrients. A diet high in fiber can help lower blood cholesterol levels and reduce the risk of heart disease. Whole grains are also important sources of vitamins and minerals, such as thiamin, riboflavin, niacin, folate, selenium, zinc and iron. Doughnuts, biscuits, cakes, Buttered popcorn and high-fat snack crackers should be avoided.

5. Practice moderation and balance

Knowing which foods to eat is the first step in creating a heart-healthy diet. The next step is to know how much food to consume. Overloading can lead to excess calorie, fat and cholesterol intake. Keep track of the number of servings you eat - and use proper serving sizes - to help control how much food you eat.

A serving size is a specific amount of food, defined by common measurements such as cups, ounces or pieces. For example, the Food Guide Pyramid developed by the Department of Agriculture and Department of Health and Human Services suggests that one serving of pasta is 1/2 cup, or about the size of an ice cream scoop. A serving of meat, fish or chicken is 2 to 3 ounces or about the size and thickness of a deck of cards. Judging serving size is a learned skill. You may need to use measuring cups and spoons and a scale until you're comfortable with your judgment.

References:

1. Walsh B: Asia's War With Heart Disease Time, November 22, 2004 / Vol. 164, No. 21
2. Lancet 2000
3. World Health Organization. World health report: reducing risks, promoting healthy life. Geneva: WHO, 2002.
4. Mayo clinic.com

The writer is senior consultant and head of department of Critical Care Medicine Fortis Hospital, Noida.