Sex and age-specific population attributable fractions of CVD risk factors combination from the pooled analysis of 85,432 participants in Japan
METHODS: Blood pressure, total cholesterol, and smoking information was obtained from 85,432 study participants from 10 cohorts in Japan. These variables were dichotomized to indicate whether there was a cardiovascular risk (hypertension [SBP ≥140 mmHg or DBP ≥90 mmHg], high cholesterol [total cholesterol ≥220 mg/dl], and smoking [current smoker]). These factors were combined to estimate the hazard ratio and their population attributable fraction (PAF). Sex and age groups (40–59/60–69/70–89 years) were separately analyzed. The cohort-stratified Cox model was applied with eight dummy variables, which indicated the combination of CVD risk factors.
RESULTS: For CVD mortality, the PAF declined with age in both sexes (men, 40–59 years: 43.7%, 60–69 years: 32.8%, 70–89 years: 21.9%; women, 40–59 years: 39.7%, 60–69 years: 21.0%, 70–89 years: 3.7%). In men, approximately half of the PAF was from people who had hypertension and smoked (40–59 years: 23.7%, 60–69 years: 16.1%, 70–89 years: 7.9%). In women, approximately half of the PAF was from people with hypertension only (40–59 years: 17.5%, 60–69 years: 11.3%, 70–89 years: 4.8%).
CONCLUSIONS: The comprehensive impact assessment of CVD risk factors from a pooled analysis shows that hypertension (both sexes) and men’s smoking are important problems that need to be solved to avoid premature CVD deaths in Japan. This finding may be applicable to other East Asian countries with similar conditions.