Objective: To assess the relationship between low cardiovascular disease (CVD) risk and the mortalities of coronary heart disease (CHD), stroke, cancer and all causes as well as life expectancy in Chinese population.
Methods: CVD risk factors were surveyed in 1982 approximately 1985 for 30 thousand male and female participants aged 35 approximately 59 from 10 Chinese population groups including 3 groups of factory workers, 6 groups of farmers and 1 group of fishermen according a uniform protocol with standardized methods. Follow-up was carried out up to 1999 approximately 2000 and the causes of death were all documented. Low cardiovascular risk was defined as: SBP/DBP < 120/80 mm Hg without anti-hypertensive medication 2 weeks before the baseline survey, serum total cholesterol < 5.17 mmol/L, BMI > 18.5 but < 24 kg/m(2) and no smoking at baseline survey. Mortality rates of CHD and stroke, cancer and all causes the participants with low CVD risk were compared with the rest of the cohort and difference in life expectancy was estimated.
Results: Out of the whole cohort of 30 560 participants, 24 900 with complete data were available for the present analysis. Among these, 4 542 participants (18.2%) were defined as low CVD risk group, including 959 (7.7%) men and 3 583 (28.9%) women. During a follow-up of 15.2 years on average, 243 deaths including 6 CHD, 15 stroke and 117 cancer deaths took place in low risk group, while 2 383 deaths including 182 CHD, 333 stroke, and 934 cancer deaths occurred in rest of the cohort. Cox proportional hazards model adjusted for age showed that the relative risks of death of CHD, stroke, cancer and all causes in low risk group were 0.51 (95% CI: 0.19 approximately 1.37), 0.30 (95% CI: 0.11 approximately 0.81), 0.86 (95% CI: 0.62 approximately 1.19) and 0.77 (95% CI: 0.62 approximately 0.96) for men and 0.11 (95% CI: 0.03 approximately 0.45), 0.31 (95% CI: 0.17 approximately 0.58), 0.84 (95% CI: 0.66 approximately 1.10) and 0.67 (95% CI: 0.56 approximately 0.79) for women, respectively. Life expectancy was 2.6 years longer for men and 4.0 years longer for women in the low risk group.
Conclusion: The mortality rates of CVD and all causes were lower and life expectancy was longer in the participants with low CVD risk. Keeping low risk profile may not only prevent from having CVD but also extend life expectancy.