Decreased survival among sedentary patients undergoing dialysis: results from the dialysis morbidity and mortality study wave 2.

BACKGROUND

Sedentary behavior is associated with an increased risk for death in the general population. However, the association between inactivity and mortality has not been studied in a large cohort of dialysis patients despite the high prevalence of sedentary behavior in this group.

METHODS

We used the Dialysis Morbidity and Mortality Study Wave 2, a prospective study of a national sample of 4,024 incident peritoneal dialysis and hemodialysis patients from 1996 to 1997, to determine whether sedentary behavior is associated with increased mortality during a 1-year period in this group after adjusting for confounding variables.

RESULTS

The study population consisted of the 2,837 patients with accurate survival data who were able to ambulate and transfer. Eleven percent of the sedentary patients died during the study period compared with 5% of nonsedentary patients. In a survival analysis, sedentary behavior (hazard ratio, 1.62; 95% confidence interval, 1.16 to 2.27) was associated with an increased risk for death at 1 year after adjusting for all variables that we postulated might be associated with survival and for differences between sedentary and nonsedentary patients.

CONCLUSION

Sedentary behavior is associated with an increased risk for mortality among dialysis patients similar in magnitude to that of other well-established risk factors, such as a one-point reduction in serum albumin concentration. More attention should be given to exercise behavior in dialysis patients, and controlled clinical trials are needed to further define the association of sedentary behavior with mortality.