Possible association of a reduction in cardiovascular events with blood donation

Heart. 1997 Aug;78(2):188-93. doi: 10.1136/hrt.78.2.188.

Abstract

Background: The iron hypothesis suggests that females are protected from atherosclerosis by having lower iron stores than men, thus limiting oxidation of lipids.

Objective: To test the iron hypothesis by comparing cardiovascular event rates in whole blood donors compared with nondonors.

Design: Prospective cohort with telephone survey follow up.

Setting: The State of Nebraska, USA.

Participants: A sample was selected from the Nebraska Diet Heart Survey (NDHS) restricting for age > or = 40 years and absence of clinically apparent vascular diseases at time of enrollment in to NDHS (1985-87).

Main outcome measures: The occurrence of cardiovascular events (myocardial infarction, angina, stroke), procedures (angioplasty, bypass surgery, claudication, endarterectomy), nitroglycerin use, or death (all cause mortality), and level of blood donation.

Results: Participants were 655 blood donors and 3200 non-donors who differed in education, physical activity, diabetes, and frequency of antihypertensive treatment; 889 were lost to follow up. Sixty four donors and 567 non-donors reported cardiovascular events (crude odds ratio = 0.50, 95% confidence interval (CI) 0.38-0.66). The benefit of donation was confined to non-smoking males (adjusted odds ratio 0.67, 95% CI 0.45-0.99). Benefit was limited to current donors (the most recent three years). No additional benefit resulted from donating more than once or twice over three years.

Conclusion: In support of the iron hypothesis, blood donation in non-smoking men in this cohort was associated with reduced risk of cardiovascular events. A randomised clinical trial is warranted to confirm these findings as the observed personal health benefit of donation has public policy ramifications.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Analysis of Variance
  • Blood Donors*
  • Cardiovascular Diseases / blood
  • Cardiovascular Diseases / prevention & control*
  • Chi-Square Distribution
  • Child
  • Child, Preschool
  • Cross-Sectional Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Infant
  • Iron / blood
  • Male
  • Middle Aged
  • Odds Ratio
  • Prospective Studies
  • Smoking / blood
  • Time Factors

Substances

  • Iron