Clustering of risk factors and the risk of incident cardiovascular disease in Asian and Caucasian populations: results from the Asia Pacific Cohort Studies Collaboration

Abstract

Objective: To assess the relationship between risk factor clusters and cardiovascular disease (CVD) incidence in Asian and Caucasian populations and to estimate the burden of CVD attributable to each cluster.

Setting: Asia Pacific Cohort Studies Collaboration.

Participants: Individual participant data from 34 population-based cohorts, involving 314 024 participants without a history of CVD at baseline.

Outcome measures: Clusters were 11 possible combinations of four individual risk factors (current smoking, overweight, blood pressure (BP) and total cholesterol). Cox regression models were used to obtain adjusted HRs and 95% CIs for CVD associated with individual risk factors and risk factor clusters. Population-attributable fractions (PAFs) were calculated.

Results: During a mean follow-up of 7 years, 6203 CVD events were recorded. The ranking of HRs and PAFs was similar for Australia and New Zealand (ANZ) and Asia; clusters including BP consistently showed the highest HRs and PAFs. The BP-smoking cluster had the highest HR for people with two risk factors: 4.13 (3.56 to 4.80) for Asia and 3.07 (2.23 to 4.23) for ANZ. Corresponding PAFs were 24% and 11%, respectively. For individuals with three risk factors, the BP-smoking-cholesterol cluster had the highest HR (4.67 (3.92 to 5.57) for Asia and 3.49 (2.69 to 4.53) for ANZ). Corresponding PAFs were 13% and 10%.

Conclusions: Risk factor clusters act similarly on CVD risk in Asian and Caucasian populations. Clusters including elevated BP were associated with the highest excess risk of CVD.

Keywords: epidemiology; myocardial infarction; preventive medicine; stroke.

Figure 1

HRs and 95% CIs for incident cardiovascular disease associated with risk factors and risk factor clusters by region. Analyses are adjusted for age, and stratified by sex and study. Individuals without any elevated risk factor were the reference group. ANZ, Australia and New Zealand; P, high blood pressure; S, current smoking; C, high total cholesterol (TC), W, high body mass index (BMI). High blood pressure was defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg, high TC was defined as a TC level ≥5.2 mmol/L and high BMI was defined as a BMI≥25 kg/m².

Figure 2

HRs and 95% CIs for incident cardiovascular disease associated with risk factors and risk factor clusters by sex. Conversions as in figure 1.

Figure 3

Population attributable fractions of risk factors and risk factor clusters for cardiovascular disease by sex and region. ANZ, Australia and New Zealand; P, high blood pressure; S, current smoking; C, high total cholesterol (TC); W, high body mass index (BMI). High blood pressure was defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg. High TC was defined as a TC level ≥5.2 mmol/L. High BMI was defined as a BMI≥25 kg/m². Combinations of risk factors were not mutually exclusive.