A Global Perspective on Coronary Heart Disease
Cardiovascular disease already exact a devastating toll in non-Western countries, and mortality and morbidity from cardiovascular disease are increasing at an alarming rate. The excerpts below are from a Perspectives article in New England Journal of Medicine in which K. Srinath Reddy portrays this epidemic as a complex challenge and an opportunity to forestall the epidemic by creatively and thoughtfully applying the lessons we have learned about public health interventions. He says, "A concerted public health response must integrate population-based prevention strategies and cost-effective clinical care, since the health systems of developing countries can ill afford the demands of technology-intensive treatments."
K. Srinath Reddy: Cardiovascular Disease in Non-Western Countries. Perspective article in: N. Engl. J. Med. 2004; 350;24.
"These epidemics [of cardiovascular disease] are driven by social and economic changes that have profound effects on living habits. Although sharp shifts in demographic patterns and lifestyle have resulted from urbanization and industrialization, the globalization that constituted the tailwind of the 20th century propelled developing countries into the worldwide epidemic of cardiovascular disease. The change reflects both a demographic shift toward increasing life expectancy and a shift in nutrition: people who live longer have greater exposure to cardiovascular risk factors, and Westernized diets and patterns of physical inactivity result in elevations in blood pressure, body weight, blood sugar levels, and lipid concentrations. A huge increase in the prevalence of diabetes will further increase the burden of cardiovascular disease; India, where nearly 20 million people had diabetes in 1995, will see at least a tripling of that number by 2025. Moreover, the global expansion of the tobacco trade has led to large increases in the rate of smoking.
The levels of these risk factors have increased steeply in most non-Western countries over the past two decades. Although there are some differences among ethnic groups in the interactions between genes and the environment, the available evidence indicates that the main risk factors for cardiovascular disease are relevant to all populations and that most of the risk is environmentally determined. Thus, these trends portend an explosion of atherothrombotic cardiovascular diseases in developing countries. Given the rate at which the distributions of body-mass index and blood cholesterol levels have changed in the Chinese population, possibly in association with a sharp increase in fat consumption, it is clear that countries like China will see a rapid escalation of the rate of coronary heart disease.
The epidemics of cardiovascular disease struck the more affluent sections of developing countries first, but as the epidemics mature, the social gradient is reversing, with socioeconomically disadvantaged groups becoming increasingly vulnerable. The poor and the less educated everywhere now use tobacco with greater frequency than the rich and the better educated do. In Brazil, women in lower-income groups have had increasing rates of overweight and obesity since 1989, in contrast to the significant decrease observed in high-income groups. Studies conducted in Indian cities in the past decade have shown that the poor have a higher risk of heart attack than the rich. The poor also have less access to health care; their risk factors are not recognized in a timely fashion; and they often do not receive effective treatment, since public health care is generally restricted to the treatment of infectious diseases. Neglect of the epidemics of cardiovascular disease will heap greater injustice on the poorest of countries and the poorest of people.
Although these developments mirror in many ways the path of the epidemics of cardiovascular disease in Western countries, there are important differences. Whereas the epidemics in the West flowed and ebbed over the course of a century, the health transition in developing countries has been compressed into a few decades. Urbanization is occurring in places with uncorrected poverty and increasing disparities in income, causing the poor to be especially vulnerable, while resource-constrained national health systems are ill equipped to cope with the double burden of infectious and chronic diseases. Globalization accelerates the change, as Western products and models of behavior are increasingly exported to non-Western countries. However, globalization also offers opportunities to facilitate the prevention of cardiovascular disease, through the application of knowledge generated in Western countries: the understanding of risk factors, evidence regarding effective interventions, tools and technology for reducing risk, new models of healthy behavior that can be promoted through the mass media. Thus, there is an opportunity to alter the pattern of health transition in developing countries by implementing effective measures for prevention and control before the epidemics peak — ideally, permitting a rapid shift to a state in which cardiovascular events occur only or primarily after 70 years of age.
A concerted public health response must integrate population-based prevention strategies and cost-effective clinical care, since the health systems of developing countries can ill afford the demands of technology-intensive treatments. The population approach is more rewarding and sustainable in the medium and long term, since even small reductions in each risk factor can add up to huge reductions in the rate of cardiovascular events. And if healthy behavior is established as a desirable norm in a society, it can have a multigenerational effect.
There are differences of opinion, however, regarding whether population-level interventions should rely principally on behavioral change governed by the personal choices of well-informed people or should operate through policy interventions that modify behavior through social and economic determinants. Western countries generally favor the personal-choice approach, but this approach assumes that healthy choices are widely available and affordable and that it is easy to educate consumers about the merits and demerits of each option. The North Karelia project in Finland provides a successful model of behavioral change through community health education combined with industry-level interventions for providing healthful food choices. Such programs, however, may be less effective in non-Western societies, where personal choice is limited by lack of awareness and highly restricted options.
Policy-level interventions have proved effective in bringing about population-wide behavioral change and risk reduction even in the short term. In Mauritius, governmental action to substitute soybean oil for palm oil as the subsidized, rationed oil resulted in a remarkable reduction in cholesterol levels. Changes in economic policy that increased the availability of fresh fruits and vegetables and helped to substitute vegetable fats for animal fats led to a sharp decline in mortality from cardiovascular causes in Poland. Non-Western countries must implement policies that will help to reduce the consumption of tobacco, salt, and unhealthful fats and increase the consumption of fruits and vegetables, through production and pricing mechanisms that increase options and influence consumer choice. But policy interventions will have limited success if the community is unwilling to accept them. Hence, the top-down approach of enabling legislation and regulation must be complemented by a bottom-up approach of community mobilization through health education. Measures taken in Western countries to protect nonsmokers from exposure to environmental tobacco smoke illustrate such a combined approach.
At the same time, people with a high risk of cardiovascular disease or clinical manifestations of disease need protection from premature death and prolonged disability. Evidence-based, context-specific, and resource-sensitive interventions must be cost-effectively integrated into all levels of health care, to strengthen both primary and secondary prevention of cardiovascular disease. The extensive use of aspirin in primary care settings for the treatment of suspected myocardial infarction can save millions of lives at low cost (about $3 per life saved, in India). Blood-pressure–lowering therapies reduce overall cardiovascular risk and have a substantial effect on mortality from coronary heart disease and stroke, and smoking cessation effectively reduces cardiovascular risk. Operational research is required to ensure the effective integration of such therapies and community-based preventive strategies into the health care systems of non-Western countries. The Initiative for Cardiovascular Health Research in the Developing Countries is a multi-institutional, international program that works to stimulate, support, and strengthen such research.
Epidemics of cardiovascular disease in non-Western countries present complex challenges but also great opportunities. Seldom in the history of human health have we been endowed with such foresight about our destiny and forearmed with such power to change it. It is a challenge to human intellect and enterprise to apply our knowledge creatively and cost-effectively to minimize the burden of cardiovascular disease throughout the world."