Predictiveness of body mass index for fatal coronary heart disease in men according to length of follow-up: a 21-year prospective cohort study.
OBJECTIVE
To test the association between body mass index (BMI) and other coronary risk factors and the risk of a fatal coronary heart disease (CHD) event in different time periods during follow-up.


METHODS
Prospective cohort study with a 21 year follow-up period. A screened sample of 14,403 men aged 40-49 years initially free of CHD. Risk of fatal CHD was calculated for 21 years' cumulative follow-up and for four consecutive 5-year periods.


RESULTS
After adjustment for age and the other risk factors, total cholesterol and systolic blood pressure retained their predictive strength for CHD mortality throughout follow-up. Though cigarette smoking remained a significant predictor, the relative risk decreased with time (test of trend: p=0.01). Intermediate to vigorous physical activity at leisure was protective for 10 years of follow-up and a question on mental stress for 5 years. The test of trend indicated that the risk associated with BMI increased with the duration of follow-up (p=0.002).


CONCLUSIONS
Our data show that coronary risk factors predicted CHD mortality differently according to the length of follow-up, and suggest that the harm associated with obesity may take more than a decade to become evident, in contrast to the classical CHD risk factors.
Håheim
Lise Lund
LL
Norwegian Health Service Research Centre, Department of Preventive Cardiology, Preventive Medicine Clinic, Ullevål University Hospital, Oslo, Norway. lise.lund.haheim@nhsrc.no
Tonstad
Serena
S
Hjermann
Ingvar
I
Leren
Paul
P
Holme
Ingar
I
D000328:Adult; D015992:Body Mass Index; D015331:Cohort Studies; D003327:Coronary Disease / Q000401:mortality* / Q000523:psychology; D015444:Exercise; D005500:Follow-Up Studies; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D013315:Stress, Psychological / Q000150:complications
D008055:Lipids