Role of brain-derived neutrophilic factor in the diagnosis of presarcopenia in patients with type 2 diabetes mellitus

Presarcopenia is the initial stage of sarcopenia, a common aging process associated with loss of muscle mass in the elderly and senile. Like presarcopenia, type 2 diabetes mellitus is an age-associated disease. Degenerative changes in skeletal muscle are a common pathogenetic factor in the two diseases. A reflection of muscle tissue functioning may be the value of the neutrophin BDNF, the expression of which increases in muscle after physical activity and also depends on the volume of muscle mass. Purpose of the study . To determine the diagnostic significance of BDNF biomarker in the diagnosis of presarcopenia in patients with type 2 diabetes mellitus. Material and methods . A one-stage single-center cross-sectional study of patients over 60 years old hospitalized in the endocrinology department of Bujanov State Clinical Hospital due to decompensation of carbohydrate metabolism was carried out. During hospitalization, the SARC-F questionnaire was used to detect sarcopenia syndrome; patients with more than 4 points were included in the main phase of the study to detect sarcopenia according to the EWGSOP 2 consensus. 88 patients were randomly selected and divided into 2 equal groups with and without presarcopenia. Sera were obtained from these patients for determination of BDNF levels by ELISA method. Statistical processing was performed using SPSS Statistics 23 program package. Results . During the study period, 232 patients were examined, of whom 147 (63% of the total number of patients, men 35 (24%), women 112 (76%), mean age 70 ± 8 years), presarcopenia was detected in 87 people (59% of the number of patients). From them 88 people were randomly selected and divided into 2 equal groups with and without presarcopenia. Patients with presarcopenia had lower BDNF levels than those without presarcopenia, with values of 5.4 ± 1.6 and 7.2 ± 1.7, respectively. When comparing the indices using Student’s t-criterion in Welch’s modification, statistically significant differences were established (p = 0.0001). When performing correlation analysis, both direct correlations of BDNF level and dynamometry of the right hand (rxy = 0.38; p = 0.0001), left hand (rxy = 0.37; p = 0.003), SPPB-test (rxy = 0.212; p = 0.048), phase angle (rxy = 0.407; p = 0.0001), as well as inverse correlations of SARC-F (rxy = –0.222; p = 0.038), ASMM (rxy = –0.236; p = 0.027), iASMM (rxy = –0.246; p= 0.021), COE (rxy = –0.348; p = 0.001). To determine the diagnostic significance of VDNF level, its dividing value was found by ROC-curve method, allowing to diagnose presarcopenia in patients with type 2 diabetes mellitus. The area under the ROC-curve corresponding to the relationship between the prediction of presarcopenia and BDNF level was 0.826 ± 0.046 with 95% CI: 0.735–0.917. The resulting prognostic model was statistically significant (p < 0.001). The threshold value of BDNF at the cut-off point was 6.71. A high risk of presarcopenia was predicted when BDNF was equal to or exceeded this value. The sensitivity and specificity of the method were 81.8 and 75%, respectively. Conclusions . Thus, the study shows that plasma BDNF protein is directly related to the risk of presarcopenia, which emphasizes the possibility of using this marker for the diagnosis of presarcopenia.