Jt. Salonen et al., DONATION OF BLOOD IS ASSOCIATED WITH REDUCED RISK OF MYOCARDIAL-INFARCTION - THE KUOPIO ISCHEMIC-HEART-DISEASE RISK FACTOR STUDY, American journal of epidemiology, 148(5), 1998, pp. 445-451
Because high body iron stores have been suggested as a risk factor for
acute myocardial infarction, donation of blood could theoretically re
duce the risk by lowering body iron stores. For this reason, the autho
rs tested the hypothesis that voluntary blood donation is associated w
ith reduced risk of acute myocardial infarction in a prospective epide
miologic follow-up study in men from eastern Finland. The subjects are
all participants of the Kuopio Ischaemic Heart Disease Risk Factor St
udy. A cohort of 2,862 men aged 42-60 years were followed for an avera
ge of almost 9 years. One man (0.7%) out of 153 men who had donated bl
ood in 24 months preceding the baseline examination experienced an acu
te myocardial infarction during 1984 to 1995, whereas 316 men (12.5%)
of 2,529 non-blood donors had an acute myocardial infarction (p < 0.00
01 for difference between proportions). In a Cox proportional hazards
model adjusting for age, examination years and all other predictive co
ronary disease risk factors, blood donors had a 88% reduced risk (rela
tive hazard = 0.12, 95% confidence interval 0.02-0.86, p = 0.035) of a
cute myocardial infarction, compared with non-blood donors. These find
ings suggest that frequent blood loss through voluntary blood donation
s may be associated with a reduced risk of acute myocardial infarction
in middle-aged men.