Cardiovascular Disease in Nonwestren Country

8/12/2019 Cardiovascular Disease in Nonwestren Country

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P E R S P E C T I V E

Concern about increasing rates of death and dis-ability due to cardiovascular disease in non-West-ern countries is often met with skepticism: Do they really constitute a serious public health problem?With justifiable alarm about the spread of humanimmunodeficiency virus and AIDS and with old foessuch as malaria and tuberculosis still posing for-midable challenges in many developing countries,it is understandable that epidemics of cardiovas-cular disease have insidiously established them-selves without attracting global attention or localaction. The fact that 80 percent of deaths from car-diovascular disease worldwide and 87 percent of

related disability currently occur in low-income andmiddle-income countries, however, indicates themagnitude of the problem. Cardiovascular diseasehas become the leading cause of death in many developing countries and will soon attain that statusin several others.

The high burden of mortality from cardiovas-cular causes in developing countries (estimated at 9 million in 1990 and expected to increase to 19 mil-lion by 2020

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) is only partially explained by theirlarge populations (see Figure 1). The projected in-crease in the proportion of all deaths that are due tocardiovascular causes, from about 25 percent in1990 to more than 40 percent in 2020, signals theadvance of the epidemics. China has witnessed adoubling of the number of deaths attributed to cir-culatory diseases during the past two decades, withthe most marked increase among persons 35 to54 years of age. Over the past 40 years, the preva-lence of coronary heart disease in urban India hasincreased by a factor of six to eight, to about 10 per-cent among persons 35 to 64 years of age. Stroke isnow the dominant type of cardiovascular diseasein China, Southeast Asia, and sub-Saharan Africa, whereas coronary heart disease predominates inLatin America, the Middle East, and urban India. Asthe so-called health transition in these countriesprogresses, hemorrhagic stroke is being replacedby thrombotic stroke and coronary heart disease asthe leading form of cardiovascular disease.

In non-Western countries, deaths due to cardiovascular disease tend to occur a decade or two ear-

lier than they do in Western countries; nearly half occur before 70 years of age, whereas only one fifthoccur so early in the West a difference attribut-able to both the earlier occurrence of cardiovas-cular events and the lower level of clinical careavailable.

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The rate of death due to stroke amongpersons 15 to 59 years of age is three to eight timesas high in Tanzania as in England and Wales. Deathand disability occurring in midlife have disastrousconsequences for families who lose wage earners,and the resulting loss in productivity adversely af-fects national development. Of the 24 million peo-ple expected to die of cardiovascular disease in

2020, about 9.3 million will be between 30 and 69 years of age; most of them will be in non-Westerncountries.

These epidemics are driven by social and eco-nomic changes that have profound effects on livinghabits. Although sharp shifts in demographic pat-terns and lifestyle have resulted from urbanizationand industrialization, the globalization that consti-tuted the tailwind of the 20th century propelled developing countries into the worldwide epidemicof cardiovascular disease. The change reflects botha demographic shift toward increasing life expect-ancy and a shift in nutrition: people who live long-er have greater exposure to cardiovascular risk factors, and Westernized diets and patterns of phys-ical inactivity result in elevations in blood pressure,body weight, blood sugar levels, and lipid concen-trations. A huge increase in the prevalence of dia-betes will further increase the burden of cardiovas-cular disease; India, where nearly 20 million peoplehad diabetes in 1995, will see at least a tripling of that number by 2025. Moreover, the global expan-sion of the tobacco trade has led to large increasesin the rate of smoking.

The levels of these risk factors have increasedsteeply in most non-Western countries over the past two decades. Although there are some differencesamong ethnic groups in the interactions betweengenes and the environment, the available evidenceindicates that the main risk factors for cardiovas-cular disease are relevant to all populations and that most of the risk is environmentally determined.

Cardiovascular Disease in Non-Western CountriesK. Srinath Reddy, D.M.

Cardiovascular Disease in Non-Western Countries


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Thus, these trends portend an explosion of athero-thrombotic cardiovascular diseases in developingcountries. Given the rate at which the distributionsof body-mass index and blood cholesterol levelshave changed in the Chinese population (see Fig-ure 2), possibly in association with a sharp increase

in fat consumption, it is clear that countries likeChina will see a rapid escalation of the rate of coro-nary heart disease.

The epidemics of cardiovascular disease struck the more affluent sections of developing countriesfirst, but as the epidemics mature, the social gradi-ent is reversing, with socioeconomically disadvan-taged groups becoming increasingly vulnerable.The poor and the less educated everywhere now use tobacco with greater frequency than the richand the better educated do. In Brazil, women in low-er-income groups have had increasing rates of over- weight and obesity since 1989, in contrast to the sig-

nificant decrease observed in high-income groups.Studies conducted in Indian cities in the past dec-ade have shown that the poor have a higher risk of heart attack than the rich. The poor also have lessaccess to health care; their risk factors are not rec-ognized in a timely fashion; and they often do not receive effective treatment, since public health careis generally restricted to the treatment of infectiousdiseases. Neglect of the epidemics of cardiovascu-lar disease will heap greater injustice on the poor-est of countries and the poorest of people.

Although these developments mirror in many ways the path of the epidemics of cardiovasculardisease in Western countries, there are important differences. Whereas the epidemics in the West flowed and ebbed over the course of a century, thehealth transition in developing countries has beencompressed into a few decades. Urbanization isoccurring in places with uncorrected poverty andincreasing disparities in income, causing the poorto be especially vulnerable, while resource-con-strained national health systems are ill equippedto cope with the double burden of infectious andchronic diseases. Globalization accelerates thechange, as Western products and models of behav-ior are increasingly exported to non-Western coun-tries. However, globalization also offers opportu-nities to facilitate the prevention of cardiovasculardisease, through the application of knowledgegenerated in Western countries: the understand-ing of risk factors, evidence regarding effective in-terventions, tools and technology for reducing risk,

and new models of healthy behavior that can be

promoted through the mass media. Thus, there isan opportunity to alter the pattern of health transi-tion in developing countries by implementing ef-fective measures for prevention and control beforethe epidemics peak ideally, permitting a rapidshift to a state in which cardiovascular events oc-cur only or primarily after 70 years of age.

A concerted public health response must inte-grate population-based prevention strategies andcost-effective clinical care, since the health systemsof developing countries can ill afford the demandsof technology-intensive treatments. The popula-tion approach is more rewarding and sustainablein the medium and long term, since even small re-ductions in each risk factor can add up to huge re-ductions in the rate of cardiovascular events. And if healthy behavior is established as a desirable normin a society, it can have a multigenerational effect.

There are differences of opinion, however, re-garding whether population-level interventionsshould rely principally on behavioral change gov-erned by the personal choices of well-informedpeople or should operate through policy interven-tions that modify behavior through social andeconomic determinants. Western countries gen-erally favor the personal-choice approach, but thisapproach assumes that healthy choices are widely available and affordable and that it is easy to edu-cate consumers about the merits and demerits of each option. The North Karelia project in Finlandprovides a successful model of behavioral changethrough community health education combined


Figure 1. Deaths from Cardiovascular Causes,Worldwide, in 1990 and Estimated for 2020.

Data are from Murray and Lopez.

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M i l l i o n s o

f D e a

t h s

f r o m

C a r

d i o v a s c u

l a r

C a u s e s

30

10

20

25

5

15

01990 2020

5

9

6

19

Non-Western (developing)countries

Western countries


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with industry-level interventions for providinghealthful food choices. Such programs, however,may be less effective in non-Western societies, wherepersonal choice is limited by lack of awarenessand highly restricted options.

Policy-level interventions have proved effec-

tive in bringing about population-wide behavioralchange and risk reduction even in the short term. InMauritius, governmental action to substitute soy-bean oil for palm oil as the subsidized, rationed oilresulted in a remarkable reduction in cholesterollevels. Changes in economic policy that increasedthe availability of fresh fruits and vegetables andhelped to substitute vegetable fats for animal fatsled to a sharp decline in mortality from cardiovas-cular causes in Poland. Non-Western countries must implement policies that will help to reduce the con-sumption of tobacco, salt, and unhealthful fatsand increase the consumption of fruits and vege-

tables, through production and pricing mecha-nisms that increase options and influence consum-er choice. But policy interventions will have limitedsuccess if the community is unwilling to accept them. Hence, the top-down approach of enablinglegislation and regulation must be complementedby a bottom-up approach of community mobiliza-tion through health education. Measures taken inWestern countries to protect nonsmokers from ex-posure to environmental tobacco smoke illustratesuch a combined approach.

At the same time, people with a high risk of car-diovascular disease or clinical manifestations of disease need protection from premature death andprolonged disability. Evidence-based, context-spe-cific, and resource-sensitive interventions must becost-effectively integrated into all levels of healthcare, to strengthen both primary and secondary prevention of cardiovascular disease. The exten-sive use of aspirin in primary care settings for thetreatment of suspected myocardial infarction cansave millions of lives at low cost (about $3 per lifesaved, in India). Blood-pressurelowering thera-pies reduce overall cardiovascular risk and have asubstantial effect on mortality from coronary heart disease and stroke, and smoking cessation effec-tively reduces cardiovascular risk. Operational re-search is required to ensure the effective integration

of such therapies and community-based preven-tive strategies into the health care systems of non-Western countries. The Initiative for Cardiovascu-lar Health Research in the Developing Countries isa multi-institutional, international program that works to stimulate, support, and strengthen suchresearch.

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 suchforesight about our destiny and forearmed withsuch power to change it. It is a challenge to humanintellect and enterprise to apply our knowledge cre-atively and cost-effectively to minimize the burdenof cardiovascular disease throughout the world.

From the All India Institute of Medical Sciences, New Delhi.

1.

Murray CJL, Lopez AD. The global burden of disease: a com-prehensive assessment of mortality and disability from diseases,injuries, and risk factors in 1990 and projected to 2020. Cam-bridge, Mass.: Harvard University Press, 1996.

2.

Reddy KS. Cardiovascular diseases in the developing coun-tries: dimensions, determinants, dynamics and directions forpublic health action. Public Health Nutr 2002;5:231-7.

3.

The world health report 2002: reducing risks, promotinghealthy life. Geneva: World Health Organization, 2002.


Figure 2. Trends in Mean Total Cholesterol Levelsamong Persons 25 to 64 Years of Age in Beijing, China.

Data are from the Monitoring Cardiovascular Disease(MONICA) study of the World Health Organization.

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To convert values for cholesterol to milligrams per decili-ter, divide by 0.02586.

M e a n

T o t a l

C h o l e s t e r o l

C o n c e n

t r a t

i o n

( m m o l

/ l i t e r

)

5.0

4.6

4.84.9

4.5

4.7

4.34.24.14.0

4.4

0

Women

Men

1984 1988 1993 1996 1999

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Cardiovascular Disease in Nonwestren Country