Questioning validity of conclusions. (Letters to the Editor).

The article by Arthur Siegel et al (Effect of Marathon Running on Inflammatory and Hemostatic Markers) is a study in bias, distortion and the art of pushing the proverbial square peg into the round hole. In the first paragraph this statement is made: "Although increasing levels of regular physical activity are incrementally cardio-protective (1,2), prolonged strenuous exercise such as marathon running may trigger acute myocardial infarction (AMI) (3) and sudden cardiac death (4,5).

Read cited reference #3. It does conclude that heavy physical exertion can trigger the onset of acute myocardial infarction, but "particularly in people who are habitually sedentary" (N Engl J Med 1993;329:1677-83). As for sudden cardiac death, read the conclusion of reference #4: "The low risk for sudden death identified in long-distance runners from the general population suggests that routine screening for cardiovascular disease in such athletic performances may not be justifiable." (J am Coil Cardiol 1996;28:428-31). And for the same subject of sudden cardiac death, reference #5 concludes: "These prospective data from a study of U.S. male physicians suggest that habitual vigorous exercise diminishes the risk of sudden death during vigorous exertion" (N Engl J Med 2000;343: 1355-61).

Please comment on these discrepancies.

Paul J. Kiell, M.D.

Far Hills, NJ

Dr. Kid's letter expresses the angst shared by many medically savvy marathoners, reaching back to the case of Phidippides as the sport's first fatality. The conundrum as shown by subsequent research is that while more exercise reduces the absolute or life-long risk of exertional sudden death, the relative risk paradoxically goes up for all comers during the race itself. In contrast to a 40-fold increase in risk for a sedentary middle-aged male during a first race, the added risk may be as little as five or six times resting baseline for seasoned recreational males in their late 50s representative of AMAA Boston runners (see reference #4 of my outline for a graph of this based on the Physician's Health Study). The most recent local case, reported by Reuters, was the sudden death of a 59-year-old Boston man about five minutes after receiving his medal as a top finisher at the Reggae Marathon in Negril, Jamaica, on December 8, 2002--intended as a qualifier for 2003.

Based on research in AMAA runners, an acute inflammatory response with procoagulant effects during rhabdomyolysis may play a role in triggering sudden cardiac death, analogous perhaps to acute cardiac events related to inflammation following small pox immunizations in an older population with underlying if previously undiagnosed coronary heart disease. A positive outcome of these studies so far is the recommendation that prophylactic use of aspirin may reduce cardiac risk during marathon running, although this remains to be proven. We need to work together to understand the cardiac and other medical risks of marathon running to identify strategies for making the sport safer for runners of all ages and abilities.

Arthur J. Siegel, M.D.

Belmont, MA