High Blood Pressure A Greater Risk For Stroke And Heart Disease In Asia Says New Study

A paper from the George Institute for International Health on theoutcomes of the study, to be published in the October 2005 issue of theEuropean Journal of Cardiovascular Prevention and Rehabilitation, notesthat high blood pressure is a key risk factor for haemorrhagic stroke,which is relatively more common amongst Asian populations. A 10mmHgincrease in systolic blood pressure was found to be associated with a72% greater risk of having a haemorrhagic stroke in Asian groups,compared with 49% in Australia and New Zealand.

Recent data suggest that hypertension (high blood pressure) ishigher in many Asian countries than in Australia. For example, around28% of people in China are estimated to have hypertension, comparedwith 19% in Australia. In India and Japan, the percentages are higherstill.

Prof. Mark Woodward, Director of the Epidemiology and Biostatistics atthe George Institute, who authored the paper, explained that"Cardiovascular disease is already the leading cause of death in manyAsian populations, but the relationships between risk factors andcardiovascular disease can differ in Asian and Western populations.

"A lack of data in the past has prevented the reliable quantificationof such differences, which, if shown to exist, would suggest thatdifferent cardiovascular prevention and treatment strategies arerequired for Asia, as compared to western countries.

"By far the greatest amount of evidence for the treatment andprevention of cardiovascular disease has come from the West, with verylimited evidence from Asia. However, Asia is a huge region, where Chinaalone accounts for approximately a fifth of the world's population. Ifwestern evidence is to be used as a basis for cardiovascular medicinein Asia, it is crucial to establish that the risk factors act at leastin a qualitative sense in Asia just as they do in western populations",said Prof. Woodward.

In Asia, stroke is proportionately more common than in Westerncountries; in some Asian countries (such as China) stroke is morecommon than coronary heart disease, the predominant form ofcardiovascular disease in the West. Haemorrhagic stroke, which is morelikely than ischaemic stroke to be fatal, is proportionately morecommon in Asia than in western societies.

"By 2020, the annual mortality from cardiovascular disease will reach25 million and will have the greatest impact on populations from thelower and middle-income countries of the Asia-Pacific region.Identifying regional differences in the strength and nature of therelationships between risk factors and cardiovascular disease mortalitymay assist in the allocation of limited resources for the primaryprevention of cardiovascular disease in countries in which healthsystems are often severely under-funded and overburdened," Prof.Woodward noted.

"Given that increases in blood pressure were more strongly associatedwith haemorrhagic stroke and coronary heart disease in Asianpopulations compared with Australia and New Zealand, population-widemeasures to lower blood pressure, such as reducing the consumption ofsalt, should be of particular benefit in Asian populations", he said.

The George Institute for International Health seeks to gatherevidence to address the growing problems of heart and vascular disease,injury, mental illness and neurological diseases through high-qualityresearch, evidence-based policy development and a range of capacitydevelopment programs. Epidemiology and biostatistics are central tomost aspects of The George Institute's research and developmentactivities. Methodological expertise in these areas is concentratedwithin the Epidemiology and Biostatistics Division at The GeorgeInstitute. Staff in this Division contribute to study design andundertake data analysis for each of the Institute programs. Inaddition, the Division has its own research and development projects.