Measurement of Muscle Strength in Haemodialysis Patients by Pinch and Hand Grip Strength and Comparison to Lean Body Mass Measured by Multifrequency Bio-Electrical Impedance.

BACKGROUND

Muscle weakness is a risk factor for mortality in haemodialysis (HD) patients; we wished to determine whether measuring the composition of the arm with bioimpedance was associated with arm muscle strength.

METHODS

We measured pinch strength (PS) and hand grip strength (HGS) in 250 adult HD patients with corresponding post-dialysis multifrequency bioelectrical assessments with segmental body analysis.

RESULTS

Mean age 64.0 ± 15.6, 66% male and 45.6% diabetic. The maximum HGS in the dominant or non-fistula arm was 18.9 ± 9.2 kg and PS 4.09 ± 1.96 kg respectively, with a correlation of r = 0.80, p < 0.001. HGS was associated with body cell mass (β 0.37, p < 0.001) and PS with appendicular muscle mass (β 0.06, p < 0.001). Both HGS and PS were independently associated with the ratio of extracellular water (ECW) to total body water (TBW); β -139.5, p = 0.024, β -44.8, p < 0.001 in the arm. The presence of an arterio-venous fistula increased the ECW/TBW ratio in the arm from 0.383 ± 0.009 to 0.390 ± 0.012, p < 0.05.

CONCLUSION

Muscle strength measured by HGS and PS was associated with both markers of whole body and segmental body composition within the arm, particularly ECW/TBW. Bioimpedance measurements and assessment of muscle strength should be measured in the non-fistula arm.