Insulin-dependent diabetes mellitus, physical activity, and death.

The beneficial effect of physical activity in the general population is well known, but, to the authors' knowledge, has not been reported for persons with insulin-dependent diabetes mellitus. In a cohort of 548 diabetes patients followed as part of the Pittsburgh Insulin-dependent Diabetes Mellitus Morbidity and Mortality Study, physical activity was ascertained by survey in 1981, and mortality was ascertained through January 1, 1988. Cases were also compared with non-diabetic sibling controls. Activity level among cases varied inversely with the occurrence of diabetic complications. Overall activity level was inversely related to mortality risk. Sedentary males (< 1,000 kcal/week) were three times more likely to die than active males (> 2,000 kcal/week). A similar, but statistically nonsignificant, relation was seen in females. Cox proportional hazards analysis controlling for potential confounders (age, body mass index, insulin dose, reported diabetes complications, cigarette smoking, and current alcohol drinking) similarly revealed that activity level was inversely associated with mortality risk. Comparison of cases with non-diabetic sibling controls identified similar activity levels for the two groups. The results suggest that activity is not detrimental with regard to mortality, and may in fact provide a beneficial effect in terms of longevity in diabetes patients.