Blood pressure and mortality during an up to 32-year follow-up.
BACKGROUND
Elevated blood pressure is an established risk factor of cardiovascular diseases, but there is a constant debate whether the association is continuous or with a threshold.


METHODS
During the 1960s (1964 onwards), 3,267 initially healthy male business executives (born 1919-1934) participated in voluntary health check-ups with measurements of cardiovascular disease risk factors. At baseline none of the men were on antihypertensive medication. Mortality follow-up was performed using national registers up to 31 December, 1995. Follow-up total and cardiovascular mortality was related to systolic (by 10 mmHg) and diastolic (by 5 mmHg, Korotkoff's 4th phase) blood pressure at baseline. Analyses were adjusted for age, body mass index, smoking and serum cholesterol.


RESULTS
During an up to 32-year follow-up, there were 701 deaths, 234 (33.4%) of them due to coronary heart disease, 49 (7.0%) to stroke, 42 (6.0%) to other cardiovascular diseases and 204 (29.1%) to cancer. Total mortality curves of the whole cohort (all age groups) were flat until 131-140 mmHg (systolic) and 81-85 (diastolic) and increased thereafter. Among men who smoked and had baseline serum cholesterol > 6.5 mmol/l (n = 986), the risk of death increased progressively with systolic blood pressure, whereas among non-smoking normocholesterolaemic men (n = 504) the association was J-shaped, i.e. higher mortality at < or = 110 mmHg than between 111-150 mmHg and a more consistent rise from 151-160 mmHg. The curves were essentially similar for cardiovascular mortality. The results were supported by analyses where major cardiovascular risk factors were controlled.


CONCLUSIONS
During a truly long-term follow-up, the relationship between systolic blood pressure and mortality was initially flat up to 131-140 mmHg although a linear relationship is suggested in men with other cardiovascular risk factors.
Strandberg
T E
TE
Department of Medicine, University of Helsinki, Finland. timo.strandberg@hus.fi
Salomaa
V V
VV
Vanhanen
H T
HT
Pitkälä
K
K
D000328:Adult; D001794:Blood Pressure; D015992:Body Mass Index; D002423:Cause of Death / Q000639:trends; D003327:Coronary Disease / Q000401:mortality / Q000503:physiopathology / Q000517:prevention & control; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000401:mortality* / Q000503:physiopathology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D012907:Smoking; D020521:Stroke / Q000401:mortality / Q000503:physiopathology / Q000517:prevention & control; D015996:Survival Rate / Q000639:trends