Relationship of the myostatin level and secondary sarcopenia in patients undergoing programmed hemodialysis

Abstract

The role of myostatin in the development of sarcopenia in patients receiving programed hemodialysis and the severity of the relationship with other risk factors, particularly between the myostatin level in the blood and skeletal muscle indicators, were analyzed. A single-stage prospective non-interventional study was conducted among 196 patients (97 women and 99 men, aged 54–66 years) receiving programed hemodialysis. After signing the informed consent form, all patients underwent a series of examinations consisting of the assessment of anthropometric data, measurement of vital signs, determination of the state of the muscular system for the diagnosis of sarcopenia, including bioimpedance, and laboratory tests (clinical and biochemical blood tests). The level of myostatin in the blood serum of patients was determined once 10 min before the next hemodialysis session. A statistically significant negative correlation of myostatin level with age (ρ = –0. 361; p 0. 001), skeletal muscle strength (ρ = –0. 140; p = 0. 05), and walking speed (ρ = –0. 245; p 0. 001) was observed. High myostatin levels were more often detected in men (U = 2633, z = –5. 462; p 0. 001). A positive correlation between the levels of myostatin and interleukin-6 was found (ρ = 0. 410; p 0. 001). The use of myostatin for the diagnosis of sarcopenia had a sensitivity of 71. 4%, specificity of 71. 4%, cut-off point of 5. 01 ng/mL, and area under the curve of 0. 714 (95% confidence interval: 0. 632–0. 795; p 0. 001). An increase in myostatin levels above 5. 01 ng/mL increases the likelihood of sarcopenia by 6. 25 times (95% confidence interval: 3. 314–11. 788; χ2 = 34. 639; p 0. 001). The chances of an increase in myostatin above the threshold value by 2,196 times according to the results of a short international questionnaire for determining physical activity (95% confidence interval: 1. 209–3. 988; χ2 = 6. 78; p = 0. 009) were higher in patients with reduced physical activity than in patients with normal physical activity. In general, in patients with chronic kidney disease receiving programed hemodialysis, along with the determination of myostatin level, a positive statistically significant association of myostatin level with interleukin-6, male sex, age, and decreased physical activity was noted, and myostatin could be used as a predictor of sarcopenia.