Long-term risk of BP values above normal for cardiovascular mortality:  a 24-year observation of Japanese aged 30 to 92 years.
OBJECTIVE
In Western populations, blood pressure (BP) measured at baseline has been reported to predict long-term (over 20 years) risk of mortality from cardiovascular diseases (CVDs). However, corresponding evidence is scarce in Asia where stroke is dominant. We investigated the association between baseline BP and 24-year mortality risk due to CVD, in a representative Japanese general population.


METHODS
We followed up a nationwide sample of 8592 Japanese, aged 30 years or above without a history of CVD and antihypertensive medication at baseline, for 24 years. Hazard ratios for CVD mortality in BP categories defined according to JCN7 criteria were estimated using Cox model adjusted for potential confounding factors with normal BP treated as the reference category.


RESULTS
We observed 689 CVD deaths. Hazard ratios for CVD mortality were progressively and significantly increased from the category of prehypertension. Population-attributable fraction (PAF) demonstrated that 43 and 48% of CVD and stroke deaths were explained by non-normal BP at baseline. Hazard ratios and PAF were remarkably higher in younger participants (aged 30-59 years) than those in the elderly (aged 60 years or above). Particularly, in younger men, 81% of CVD deaths were explained by non-normal BP. In sensitivity analysis, participants with antihypertensive medication showed the highest hazard ratio for CVD morality compared with the other categories.


CONCLUSIONS
BP levels above normal at baseline retained significant relative and absolute risks of CVD and stroke mortality during 24 years. Long-lasting burden of non-normal BP particularly in younger individuals suggests the importance of primary prevention of high BP from younger generation.
Department of Health Science, Lifestyle-Related Disease Prevention Center, Shiga University of Medical Science, Otsu, Shiga, Japan. takasima@belle.shigamed.ac.jp
Naoyuki
N
Takashima
Takayoshi
T
Ohkubo
Katsuyuki
K
Miura
Tomonori
T
Okamura
Yoshitaka
Y
Murakami
Akira
A
Fujiyoshi
Shin-Ya
SY
Nagasawa
Aya
A
Kadota
Yoshikuni
Y
Kita
Naoko
N
Miyagawa
Takashi
T
Hisamatsu
Takehito
T
Hayakawa
Akira
A
Okayama
Hirotsugu
H
Ueshima
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D001794:Blood Pressure / Q000502:physiology*; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000208:ethnology / Q000401:mortality*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000208:ethnology / Q000503:physiopathology*; D007564:Japan / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D058246:Prehypertension / Q000150:complications / Q000208:ethnology / Q000503:physiopathology; D016016:Proportional Hazards Models; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology / Q000208:ethnology / Q000401:mortality; D015996:Survival Rate