DR. RICHARD GAMMON

While it is often said that “one blood donation may save three lives,” it should be noted that there is also the potential for medical benefits to the donor. There have been several studies published in recent years that support this claim.

The first involved a research team that performed a follow-up study of 2,682 men from Eastern Finland who had participated in the Kupio Ischemic Heart Disease Risk Factor Study. The initial study found that men with high amounts of iron stored in their bodies had almost three times as many acute myocardial infarctions (AMI) as men with lower iron stores. The hypothesis of the follow-up study was that blood donation could reduce the risk of AMI by lowering body iron stores. The men, aged 42 to 60 were followed for an average of nine years. One out of 153 (0.7 percent) who had donated blood in a 24-month period experienced AMI compared to 316/2,529 (12.5 percent) who did not donate blood during the study period. After accounting for predictive coronary risk factors, including age, the researchers concluded that blood donors had experienced an 88 percent lower risk of AMI.

A second review was a retrospective cohort study conducted by the Community Blood Centers of Greater Kansas City. Questionnaires were sent to 1508 adults who donated more than one unit of blood each year between 1988 and 1990 (frequent donors) and 1508 age-and sex-matched adults who donated only a single unit in that 3-year period (casual donors).
Study subjects were queried regarding weight and height, smoking status, current use of medications for hypertension, hyperlipidemia, and diabetes mellitus, family history of cardiovascular disease and personal cardiovascular events prior to 1988. Occurrence of AMI, percutaneous transluminal coronary angioplasty or coronary artery bypass grafting since 1990 (events) was ascertained and permission for release of hospital records was requested. Discharge summaries were used to confirm events and death certificates were obtained for all deaths. A total 2104 subjects were surveyed a median of 10 years after the index donation. The study found that frequent donors weighed less and were less likely to be currently taking antihypertensive and lipid-modifying drugs. It also noted that cardiovascular events occurred in 6.3 percent  of frequent vs. 10.5 percent of casual donors.

The third study, Iron (Fe) and Atherosclerosis Study (FeAST), was a multicenter, randomized controlled, single-blinded trial conducted within the Department of Veterans Affairs Cooperative Studies Program and was designed to test the hypothesis that reduction in body iron stores by phlebotomy would influence clinical outcome in patients with symptomatic but stable peripheral arterial disease (PAD). The study involved 1,277 patients and was conducted May 1, 1999 through April 30, 2005.
Patients were assigned to a control group (n=641) or to a group undergoing reduction of iron stores by phlebotomy with removal of defined volumes of blood at six-month intervals (n=636). The primary end-point was all cause mortality; the secondary end point was death plus nonfatal AMI and stroke. The study found no significant differences between treatment groups for the primary or secondary study end points. However, all-cause mortality was higher in the control group- 148 patients (23 percent) vs. 125 (20 percent) in the iron-reduction group. Also, death and nonfatal AMI and stroke occurred in 205 (32 percent) of the control group vs. 180 (28 percent) of the iron-reduction group.The hypothesis that accumulated iron contributes to disease risk through iron-catalyzed free radical-mediated damage to critical biomolecules and through altered cellular function rests on secure biomedical grounds. Haidari et al found a significant relationship between serum ferritin levels and risk of coronary artery disease in male patients younger than 50 years old. Ramakrishna et al reviewed evidence consistent with a contribution of iron to atherosclerosis but at a relatively early age. However, it should be noted that the relationship between iron and disease has not been firmly defined due to variability in study design.

Selection bias may account for some of the lower rates of heart disease seen with blood donors. First, blood donors are more likely health conscious and may have healthier behavior than nondonors. Second, donors must satisfy rigorous donation testing, if active cardiovascular disease is detected, they may be excluded from donating. 

In conclusion, large multicenter studies such as the data obtained from The FeAST study show that it should be possible to test definitively whether controlling iron levels may reduce disease risk. Additional research is needed to further define ferrotoxic diseases, stratify risk reduction with intervention and clarify mechanisms; particularly in younger patients. Currently, there are several published studies that suggest a relationship between blood donation and a reduction in cardiovascular events.

Dr. Richard Gammon is medical director for Florida’s Blood Centers.



July 2008