Serum Brain-Derived Neurotrophic Factor and Myostatin Levels Are Associated With Skeletal Muscle Mass in Kidney Transplant Recipients.

BACKGROUND Sarcopenia, or reduced muscle mass, can be an important complication in kidney transplant recipients. The skeletal muscles were recently reported to secrete various myokines, such as brain-derived neurotrophic factor (BDNF) and myostatin, to regulate their mass, function, or both. The aim of the present study was to analyze the interrelationship between myokines (BDNF and myostatin) and skeletal muscle mass in kidney transplant recipients. METHODS The study population comprised 40 patients who underwent kidney transplantation at Kansai Medical University Hospital. Twenty patients had low skeletal muscle mass index (SMI) values, as measured on dual-energy x-ray absorptiometry, and were categorized into 2 groups (low SMI and normal). RESULTS Mean serum BDNF levels were 15.7 ng/mL in the low SMI group and 17.8 ng/mL in the normal group (P = .013). Mean serum myostatin levels were 362 pg/mL in the low SMI and 267 pg/mL in the normal group (P = .024). There was a significant positive correlation among metabolic equivalents and serum BDNF levels (r = 0.817; P < .001) and a significant negative correlation among metabolic equivalents and serum myostatin levels (r = -0.541; P < .001). Receiver operating characteristic analysis showed that serum BDNF and level of area under curve was 0.712, and serum myostatin level of area under the curve was 0.690. Serum BDNF and myostatin levels showed no significant difference. CONCLUSION These results suggest that BDNF and myostatin are potential biomarkers of reduced muscle mass in kidney transplant recipients.