Patient-reported outcomes: association between physical activity and quality of life in patients with chronic kidney disease

Background
Lifestyle factors contribute to the risk of progression of chronic kidney disease (CKD). CKD patients are getting older, have decreased physical activity (PA) and increased psychosocial problems. Muscle weakness and fatigue causes poor functional ability, especially with impaired renal function.

Objectives
The aim of the study was to find associations between PA and self-reported patients’ outcomes in CKD patients.

Material and methods
Consecutive adult patients with CKD (total n = 130; estimated glomerular filtration rate (eGFR) ≥ 45 mL/ /min/1.73 m2 n = 54; eGFR < 45 mL/min/1.73 m2 n = 76) or other chronic conditions (n = 247) referred to Internal Medicine Clinic were recruited. A population-based control group was randomly selected (n = 327). The International Physical Activity Questionnaire (IPAQ) short form was opted to assess PA. The 36-Item Short Form Health Survey (SF-36) was used to assess patients’ health-related quality of life (HRQoL).

Results
All HRQoL dimension scores in patients with noticeably reduced kidney function (eGFR < 45 ml/min/1.73 m2) were statistically significantly lower in comparison with other groups, except the mental health (RE) score. In the CKD low group, the PA level significantly influenced both overall physical component score (PCS) and subscales and was strongly related with walking habits (PCS, p = 0.0002). Walking positively influenced the mental component score (MCS, p = 0.007) in the CKD low group.

Conclusions
We found that subjects with severely impaired kidney function and good walking habits have higher quality of life scores. Using these instruments for measurement, we can evaluate patient-reported outcomes, and regular control helps us to improve quality of life among patients with CKD.