Public health significance of four cardiovascular risk factors assessed 25 years ago in a low prevalence country

Abstract

The individual and combined effect of cardiovascular disease (CVD) risk factors (RFs) on CVD mortality varies between populations. Our aim was to examine this association and its public health impact in Switzerland, a country with comparably low CVD mortality. We included 9853 men and women aged 25-74 years who participated in the Swiss MONICA (MONItoring of trends and determinants in CArdiovascular disease) study (1983-1992) and were followed up for survival until 2008. Adjusted Cox regression was used to calculate CVD mortality hazard ratios (HR). CVD-RFs were obesity (body mass index ≥ 30 kg/m(2)), smoking (≥ 1 cig/d), high blood pressure (≥ 140 or ≥ 90 mmHg), and total: high-density lipoprotein cholesterol ratio (≥ 5.0). Besides age and sex, models were adjusted for diet, physical activity, educational class, marital status, and the respective other CVD-RFs. After adjustment for age and sex, the HR of CVD death was for obesity 1.86 (95% CI 1.50-2.31), for smoking 1.63 (95% CI 1.32-2.01), for high blood pressure 1.42 (95% CI 1.16-1.73), and for high cholesterol ratio 1.30 (95% CI 1.06-1.60). Adjustment for other covariates moderately attenuated estimates. CVD-RFs had an independent and synergistic effect and accounted for 43.0% of population attributable risk. The presence of all four compared to zero CVD-RFs was associated with a 9.6 years shorter expected survival for a man aged 50. Most CVD deaths could be avoided by prevention of four traditional CVD-RFs. Reduction of smoking prevalence and avoidance of weight gain in the population are the most effective measures. Particular attention should be dedicated to persons with multiple CVD-RFs.