We thank Batty and Shipley for highlighting some additional articles relevant to the association between physical activity and mortality among persons with diabetes. In our summary of the key studies, we purposely did not include those by Ford and DeStefano1 and Saito et al2 because they only briefly reported physical activity as one of many risk factors; they either used a single crude measure of physical activity1 or did not examine physical activity in their main multivariate analyses.2 We did not include the article by Kohl et al2 because it did not measure physical activity but rather cardiorespiratory fitness, which we consider to be an important but different risk factor. As such, we did not consider these studies to be independent examinations of the impact of physical activity on disease incidence and mortality. We appreciate Batty and Shipley pointing out their own study4 as well as a study published this year from the Health Professional's Follow-up Study,5 which also examine the impact of physical activity and found results consistent with our own. Regrettably, these studies were published after our article was in press5 or under final review4 and thus were not included.
Gregg EW, Gerzoff RB, Caspersen CJ, Williamson DF, Venkat Narayan KM. Article on Walking and Diabetes Omitted Some Relevant Studies—Reply. Arch Intern Med. 2003;163(21):2647-2648. doi:10.1001/archinte.163.21.2647-a