Physical Function and Walking Linked to Survival in CKD

For patients with chronic kidney disease, self-reported measures of physical functioning and physical activity are independently associated with survival, reports a study in Clinical Kidney Journal.

Such self-reported measures of functioning and physical activity may be reasonable surrogates for objective assessments, the study authors noted.

The cohort study included 450 adult patients with CKD not requiring renal replacement therapy (RRT), enrolled in a study of physical therapy in CKD. Fifty-seven percent of the patients were men. The median age was 62 years, and the median eGFR was 29 mL/min/1.73 m2.

At enrollment, patients completed questionnaires regarding physical function (the Duke Activity Status Index, or DASI) and habitual activity (the General Practice Physical Activity Questionnaire). Mortality was assessed at a median follow-up of 43 months; renal replacement (RRT) was evaluated as a competing event.

During follow-up, 74 patients died and 101 initiated RRT. For patients above a DASI cutoff score of 19.2, the adjusted subdistribution hazard ratio (SHR) for death was 0.51. Each 1-unit increase in DASI score was associated with a 3% reduction in mortality.

Increased walking was also associated with increased survival. Compared to no walking, adjusted SHRs for mortality were 0.48 for participants who walked less than 1 hour per week, 0.25 for those who walked 1 to 3 hours, and 0.48 for those who walked 3 or more hours per week. For those who reported a walking speed of 3 mph or faster, the adjusted SHR was 0.37, compared to less than 3 mph.

Decreased physical function is a risk factor for mortality in patients with CKD. Higher self-reported physical function, weekly walking time, and walking speed are independently associated with increased survival among CKD patients not initially requiring RRT. Used together with clinical information, the DASI and patient-reported walking behavior may provide useful prognostic information for identifying patients at risk of adverse events, the authors said.

October/November 2018 (Vol. 10, Number 10 & 11)

References

1. Clarke AL, et al Association of self-reported physical function with survival in patients with chronic kidney disease. Clin Kidney J 2018; DOI: 10.1093/ckj/sfy080.