A comparison of the associations between risk factors and cardiovascular disease in Asia and Australasia

BACKGROUND: Cardiovascular disease is already the leading cause of death in many Asian populations. Relationships between vascular risk factors and cardiovascular disease may differ in Asian and western populations. Previously, a lack of prospective data has prevented the reliable quantification of such differences, which, if they were shown to exist, would suggest that novel cardiovascular prevention and treatment strategies are required for Asia. DESIGN: An individual participant data meta-analysis of 32 studies from the Asia-Pacific region involving 331 100 subjects (75% from Asia; 25% from the predominantly Caucasian populations of Australia and New Zealand). METHODS: Outcomes were death from coronary heart disease, ischaemic and haemorrhagic stroke. Hazard ratios were estimated from Cox models for systolic blood pressure (SBP), total cholesterol, triglycerides, body mass index, diabetes and current cigarette smoking, stratified by study and sex and adjusted for age, the other risk factors and regression dilution. RESULTS: After an average period of follow-up of 4 years there were 2082 deaths from coronary heart disease, 600 from haemorrhagic stroke and 420 from ischaemic stroke. The direction and strength of the associations between risk factors and cardiovascular outcomes were similar in the two regions, although in two cases there were significant differences. Triglycerides were more strongly associated with coronary heart disease in Australia and New Zealand (P=0.03), whereas SBP showed a stronger relationship with haemorrhagic stroke in Asia (P=0.04). CONCLUSIONS: Classical vascular risk factors act similarly in Asian and Caucasian populations; prevention and treatment strategies should thus be similar. Blood pressure reduction should be particularly effective in Asia.