Pinch grip strength as an alternative assessment to hand grip strength for assessing muscle strength in patients with chronic kidney disease treated by haemodialysis: a prospective audit.

Abstract

Muscle weakness and wasting are prevalent in haemodialysis (HD) patients, and substantially increase mortality. Convenient, readily applicable screening tests for routine clinical practice are required. Hand grip strength (HGS) has been validated in HD patients but cannot be readily measured during a HD session. On the other hand, pinch strength (PS) can be measured during a HD session, and we aimed to compare the two methods of assessing muscle strength. We measured pinch strength (PS) and hand grip strength (HGS) in 209 adult HD patients. The mean of three measurements was taken. The mean (SD) HGS was 15.3 (7.1) kg, compared to a PS of 2.9 (1.5) kg (P < 0.0001). HGS was weaker in the arteriovenous fistula (AVF) arm than the non-AVF arm [14.01 (6.9) versus 16.4 (7.1) kg (P < 0.001)], as was PS [AVF arm 2.63 (1.30) versus 3.08 (1.65) kg (P < 0.001)]. We found a strong correlation between HGS and PS (r = 0.82, P < 0.001. Comparing HGS and PS, we found a mean difference of 12.08 kg (Bland-Altman analysis), although the absolute difference was smaller with lower HGS. We found PS to be highly correlated with HGS, and was more convenient for patients because PS could be readily performed during the HD session. PS may provide an easier screening tool for muscle strength than HGS for dialysis patients, although further validation studies are required.