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Epidemiology:
Ischemic heart diseases have become a ubiquitous cause of morbidity and leading contributor to mortality in most South East countries.27.The health status and disease profile of human societies have historically been linked to the level of their economic development and social organizations with industrialization, the major causes of death and disability, in most advanced societies have shifted from predominance of nutritional deficiencies and infection disease, these classified as chronic diseases such as cardiovascular disease, diabetes and cancer. This shift has been termed epidemiological transition 28. At any given time the different countries of the World or even different regions with in a country are at different stages of epidemiological transition. This transition can occur not only between different disease categories (e.g. death from childhood diarrhea and malnutrition giving way to adult chronic diseases) but also within specify diseases category( e.g. rheumatic heart disease of long giving way to chronic coronary artery diseases of middle age or valve calcification and degeneration and heart failure of elderly) 29. The World Health Organization (WHO) stated in 2002 that in many regions some of the most formidable enemies of health are joining forces with the allies of poverty to impose a double burden of diseases, disability and premature death in many millions of people 30. This is what is happening in the South Asia, which houses one quarter of Global population and half of which lives below poverty line and has limited access to health care. The meager capita average budgetary expenditure on health ranging between US$ 11-20 31. For different countries of the region further highlights this challenge.
Burden of Cardiovascular diseases:
According to WHO estimates, in 2003, 16.7 million people around the globe die of cardiovascular diseases each year. This is over 29% of all deaths globally32. By 2020 atherosclerotic disease will become the leading cause of both death and disability worldwide, with the number of fatalities projected to increase to more than 24 million a year by 2030 33. This trend has given implication for countries in south Asia. Immigrant South Asians in the developed world have higher rates of cardiovascular diseases as compared to native people. Some studies suggest that the rate of diseases in the south Asians parallel those in the industrialized world. South Asians immigrants to united kingdom, south Africa, Singapore, and North America experience 1.5 times higher coronary heart disease mortality compared with indigenous population. 34,35,36. Located in the South Asia, Pakistan has a population of 140 million 37. Surveys in Pakistan indicate very high prevalence rates of cardiovascular disease and risk factors with over 30% of the population over 45 years of age affected 37. In addition to High prevalence, cardiovascular disease appears to have a significantly younger onset and is known to be move aggressive in its presentation 38.
Temporal Trend:
The average life expectancy in India has increased from 41 years 1957 to 1961 to 61.4 in the years 1991 to 1996 and is projected to reach 72 years by 2030 which could lead to large increase in the cardiovascular disease prevalence 39. Death from cardiovascular disease in India increased from 1.17 millions in 1990 to 1.59 million in 2000 and are expected to rise to 2.03 million in 2010 40. A study done in 1994 found that prevalence of cardiovascular disease in Srilankan man aged 35-59 is 1.6% out of which 1.9% in higher and 0.6% in lower socioeconomic groups in Urban population 48.
On the whole morbidity and mortality both are increasing in South Asian population with the period of time due to cardiovascular disease.
Risk Factors:
Smoking, Hypertension, and diabetes are strongly associated with cardiovascular disease among south Asians 41. In addition to traditional risk factors, there is increasing evidence that elevations from blood glucose even in non diabetic range increases cardiovascular disease risk amongst South Asians.
South Asians have elevated levels of LDL, which increases risk of atherosclerosis and thrombogenesis 42. Recent studies have confirmed that South Asians have also higher levels of homocystein, fibrinogen and plasminogen activator inhibitor (PAI-1) and low HDL all of which could increase risk of thrombosis 43.
Lifestyle Changes:
Rural communities have lower risk factors than urban westernized population. With the rapid rural to urban migration in South Asia, prevalence of cardiovascular disease is increasing in urban population. Several cross-sectional surveys of urban and rural areas of different south Asian countries revealed that a higher prevalence of cardiovascular disease in urban population was associated with higher levels of body mass index, blood pressure, fasting blood lipids and diabetes.49,50,51.. A recent overview of prevalence surveys conducted over two decades in India reported a 9 fold increase in CHD in urban population compared with 2 fold increase in CHD rates among rural population. 52. Impaired fetal nutrition resulting in low birth weight is another rich factor which increases the prevalence of CHD in South Asians.53. This has also been implicated in the causation of metabolic syndrome, diabetes, and hypertension in later life. 54. This association has profound effect on South Asian Population where fetal and maternal malnutrition is common.
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