Letters Section Editor: Stephen J. Lurie,
MD, PhD, Senior Editor.
To the Editor: Dr Tanasescu and colleagues1 found that more intense exercise was associated
with reduced risk of coronary heart disease (CHD). The authors acknowledge
the possibility of potential confounding factors (the "healthy cohort" effect)
and appropriately adjusted for these variables in their analyses. Nonetheless,
the authors did not adjust for aspirin use, despite the known association
between aspirin use and risk of CHD.2 It
is possible that self-selected aspirin use among health professionals could
be associated with patterns of exercise, similar to the authors' observation
of increasing use of vitamin E supplements with increasing level of physical
activity. If information concerning aspirin intake were available it would
be of interest to note whether accounting for its use influences the observed
relationship between exercise and CHD.
Burack R. Exercise Intensity and Risk of Coronary Heart Disease. JAMA. 2003;289(4):419-420. doi:10.1001/jama.289.4.419-a