Impact of Hypertension and Subclinical Organ Damage on the Incidence of Cardiovascular Disease Among Japanese Residents at the Population and Individual Levels ― The Circulatory Risk in Communities Study (CIRCS) ―

BACKGROUND: In Japan, a community-based screening program for cardiovascular disease (CVD) has been effective in preventing stroke and coronary artery disease (CAD). The present study aimed to clarify which risk factors assessed at the screening examinations affect the incidence of CVD and the magnitude of the association after the late 1990 s. METHODS AND RESULTS: We conducted a 12.5-year prospective study of 10,612 Japanese residents aged 40-74 years between 1995 and 2000, initially free of CVD and who underwent the screening examinations. During the follow-up, 364 cases of stroke and 137 cases of CAD were identified. The population attributable fraction of stroke was the largest for hypertension (HT; 46%), while the relative risk of stroke was the highest for atrial fibrillation (multivariable hazard ratio, 4.9; 95% confidence interval, 2.9-8.3). The population attributable fraction of CAD was relatively large for HT, current smoking, and high non-high-density lipoprotein cholesterol (20-29%). A dose-response relationship was found between the incidence of these cardiovascular events and the number of comorbid hypertensive subclinical organ damage markers: funduscopic changes, ST-T changes on ECG at rest, proteinuria and low estimated glomerular filtration rate. CONCLUSIONS: HT and hypertensive subclinical organ damage are significantly associated with incident stroke and CAD at the population level, suggesting that management of HT and assessment of subclinical organ damage in hypertensive subjects at a screening program are still beneficial for community-based CVD prevention.