大規模コホート研究の知見：ＮＩＰＰＯＮ ＤＡＴＡより

Abstract

The NIPPON DATA is a large-scale cohort study based on a representative Japanese population for men and women aged 30 years and over who were randomly selected through out Japan. The NIPPON DATA80 and the NIPPON DATA90 comprise about 10,000 and 8,000 participants, respectively. The baseline surveys were conducted in 1980 and 1990, respectively. These tow cohorts have been followed up to the year 2004 and 2005, respectively and cause specific deaths were determined by linking with the government mortality statistics in Japan with proper permission. Here, the findings of the 19-year follow-up from NIPPON DATA80 are mainly described. For the relationship between blood pressure and stroke mortality; the higher the blood pressure level, the higher the risk of stroke mortality. Compared with the category of the optimal blood pressure level (systolic blood pressure (SBP) /diastolic blood pressure (DBP), <120/<80 mmHg) defined by the Joint National Committee, USA (JNC6), stroke mortality risk for the category of high blood pressure (SBP≥180 mmHg and/or DBP 110 mmHg) was 5-fold higher. For men, the significant graded and positive relationship of SBP with the risk of cardiovascular disease (CVD) death was observed from the young to the old age group (30-64 years, 65-74 years, and 75 years and more). Age-adjusted stroke mortality in Japan has declined by around 80% during the period of 1965-1990, and this has been observed with a concomitant great decline in population blood pressure level. In conclusion, it is very important for people to keep their blood pressure levels in control all along their life by maintaining healthy lifestyles.