Factors Affecting Daily Physical Activity and Physical Performance in Maintenance Dialysis Patients

Maintenance hemodialysis (MHD) patients display reduced daily physical activity (DPA) and physical performance (PP). Previous studies did not differentiate the effects of kidney failure and MHD treatments from comorbidities as causes for reduced DPA and PP. In relatively healthy MHD patients and normal adults, we evaluated DPA and PP and examined relationships between DPA and PP and possible associations between anxiety or depression and DPA and PP. DPA, 6-minute walk distance (6-MWD), sit-to-stand (STS), and stair-climbing tests were measured in 72 MHD patients (40% diabetics) with limited comorbidities and 39 normal adults of similar age and gender mix. Anxiety and depression were measured by the Beck anxiety and depression inventories. DPA, time-averaged over 7 days, and all 3 PP tests were impaired in MHD patients, to about 60% to 70% of normal values ( P P P P r  = −0.33, P  = .006) but not anxiety. DPA on the hemodialysis day ( P  = .01), day after dialysis ( P  = .03), and day 2 after dialysis ( P  = .03) each correlated negatively with degree of depression but not with anxiety. MHD patients displayed negative-adjusted correlations between anxiety and 6-MWD ( P  = .03) and STS ( P  = .04). In relatively healthy MHD patients, DPA and PP are substantially impaired and correlated with each other, even in patients without evidence for anxiety or depression. Anxiety and depression are common in MHD patients and are associated with further impairment in DPA and PP.