FP778CAN FINGER PINCH STRENGTH BE USED AS AN ALTERNATIVE TO HAND GRIP STRENGTH FOR ASSESSING MUSCLE WEAKNESS IN HAEMODIALYSIS PATIENTS

Abstract

Introduction and Aims: Haemodialysis (HD) patients are at risk of muscle wasting (sarcopenia), and once sarcopenia develops then patients are at increased risk of mortality. As such it is important to be able to screen HD patients for muscle weakness to allow for intervention. Muscle weakness assessed by hand grip strength (HGS) has been shown to be associated with increased risk for death. However HGS requires the patient to be seated with the arm fully extended, and as such cannot be reliably assessed when patients are treated by HD. On the other hand pinch strength (PS), measures the strength of thumb and index finger strength, and can be easily measured when patients are on HD, as only requires wrist to be in the neutral position. However PS has not been validated against HGS which is the aim of this study. Methods: HGS and PS were measured in patients attending for outpatient HD. The mean of three measurements was taken, and we compared HGS and PS measurements between arms; access vs non‐access and right vs Left arms. We measured body composition using multifrequency bioelectrical impedance postdialysis. We looked for factors associated with HGS and PS, including Age, Sex, DM, Davies co‐morbidity score and grade, dialysis vintage, NT‐proBNP, C reactive protein, cholesterol, B2Microglobulin, Haemoglobin (Hb), body mass index (BMI), Skeletal muscle mass (SKM) percentage of body fat mass (PFM), the ratio of extracellular to total body water (ECW/TBW). Analysis was computed using SPSS 17 Results: PS and HGS were measured in 209 HD patients, 69% male, 45% diabetic, mean age 64.2 ± 15.6 yr, median Davies co‐morbidity score=1 (IQR=1,0‐5). The mean HGS in the non‐fistula arm was 16.43 ±7.13 Kg, compared to a PS of 3 ±7.13 Kg, p<0.0001. There was a strong correlation between HGS and PS, r=0.81, p<0.001. There was a significant difference (p<0.001) in PS measured in 125(60%) patients between right and left hands (3±1.61 Kg vs left 2.62 ±1.33 Kg respectively), and with an ipsilateral arterio‐venous fistula (AVF) and the contralateral hand (AVF 2.62 ±1.36 Kg vs non AVF 3.12 ±1.62 Kg, p<0.001). There was a positive correlation for HGS on linear regression with male gender (β=0.31, 95%CI (3.42‐8.29), p<0.001), and PFM (β=0.14, 95%CI (0.13‐0.23), p<0.001), HGS was negatively correlated with age (β=‐.28,95%CI (‐.23 ‐ ‐.08), p<0.001), Davies score (β=‐.145, 95%CI (‐2.28 ‐ ‐.1), p=0.031). There was a positive correlation for PS with male gender (β=0.32, 95%CI (0.82 ‐ 1.8),p<0.001), PFM (β=0.13,95%CI(0.002‐.046), p=0.036), log dialysis vintage (β=0.18, 95%CI (0.003‐0.01), p=0.004). PS was negatively correlated with age (β= ‐.275, 95%CI (‐.05‐ ‐.017), p<0.001), DM (β= ‐.177, 95%CI(‐1.17‐ ‐.18), p=0.008), and B2Micoglobulin (β= ‐.16, 95%CI(‐.060‐ ‐ .007), p=.014). there was no correlation between either HGS and PS and total body skeltal muscle mass. Conclusions: There was a strong correlation between HGS and PS and PS is an easier test to carry out and can be done whilst patients dialyse. Thus PS could potentially be used instead of HGS to assess and screen for muscle weakness in HD patients. As expected both HGS and PS are postively associated with male gender and PFM, and negatively with age. However PS and HGS assessments of hand strength did not correlate with measurements of total body muscle mass.