The effects of iron parameters on muscle strength, muscle elasticity and functional capacity of haemodialysis patients

Objective: This study aimed to determine the effects of iron load on muscle strength, stiffness, and the functional capacity of hemodialysis (HD) patients. Materials and Methods: 40 patients aged ≥18 years who had been on HD for at least one year were included in the study. Ferritin>700 ng/dl or TSAT>40 was considered iron overload (Patient group). Adult patients with ferritin >100 ng/dl were included as a control group. Dominant elbow flexion muscle strength (biceps) and bilateral knee extension muscle strength (quadriceps) were measured using a dynamometer. Muscle SWV was measured with ultrasound elastography using the ARFI method. The 50-meter walking test was used to evaluate functional performance. The results were analyzed with IBM SPSS V23 and IBM AMOS V24. Results: There were differences between the patient and control groups in terms of age (51.05 ± 15.45 years vs. 62.06 ± 11.21 years; p=0.016), HD duration (4.23 ± 2.94 years vs. 6.64 ± 3.74 years; p=0.037), ferritin level (284.41 ± 106.52 ng/ml vs. 1114.62 ± 418.53 ng/ml; p<0.001) and TSAT level (27.05 ± 5.59% vs. 37.46 ± 13.60%; p=0.006). Muscle strength was lower, 50 m walking time was longer, and muscle SWV values were higher in the patient group. Ferritin did not affect muscle strength. TSAT was only effective on right leg muscle strength (=0.165; p=0.031). Ferritin increase decreased the 50-meter walk test time (β2=-0.010; p<0.001) and increased muscle SWV values (β2=0.001; p<001). TSAT did not affect either the elasticity or the walking test. Conclusion: Ferritin was found to be associated with muscle stiffness and functional capacity in HD patients. Studies are needed to explain the cause and effect relationship. Keywords: Hemodialysis, iron overload, muscle strength, muscle stiffness