Examination of BDNF, GDNF, and neurotrophin 3 levels and brain volumes in men working shifts

Introduction: Sleep is a periodically determined period of time in which almost all living things live. Sleep disturbances are observed in guard duty individuals. There are studies suggesting that sleep disorder affects neurotrophin levels, which are responsible for learning, memory and cognitive functions. Neurotrophins are a family of polypeptide growth factors that influence the proliferation, differentiation, survival and death of neuronal and non-neuronal cells. Brain-derived neurotrophic factor (BDNF), Glial-derived neurotrophic factor (GDNF) and Neurotrophin 3 are members of this family. They are responsible for learning and memory formation by triggering new synapse formation and synaptic plasticity. Purpose: The aim of this study is to examine BDNF, GDNF and Neurotrophin 3 levels and brain volumes in men who work on shifts. Method: This research is a prospective observational study. The study was started after the ethics committee approval was obtained from the Clinical Research Ethics Committee of Kırşehir Ahi Evran University, dated 06.04.2021 and numbered 2021-07/78. Forty-nine men who work on shifts for at least 1 year were included in the study. On-duty work is based on shifts (minimum of ≥4 days/1 month) that only include night work starting from approximately 4 pm. Group 1 (short-term workers (1-5 years)) (n=25) and Group 2 (long-term workers (over 5 years)) (n=24) were made according to the duration of shift work. The sociodemographic information of the individuals and their information about working in shifts were obtained and PUKI was applied to evaluate the sleep quality. MOCA and Trail Making Test were used to evaluate cognitive performance and Beck Anxiety Inventory was used to evaluate anxiety level. Approximately 5 cc of blood was taken into 1 EDTA tube and plasma BDNF, GDNF and Neurotrophin 3 levels were examined. Using the T1-weighted axial image group on MRI images with 3 Tesla device acquisition, the data, which were made analyzable by Matlab 7.10.0, one of the MR image processing programs, were measured and reported using the Volbrain (84) and MriCloud (85) applications, which are volume measurement programs. Results: According to the results of our study, it was determined that Group 2 had a significant (p<0.05) decrease in BDNF and NT-3 levels, and an insignificant (p>0.05) decrease in GDNF levels. It was determined that there was no significant difference in the volumes of the relevant brain regions between the two groups (p>0.05). According to the PUKI results, it was determined that both groups had poor sleep quality and there was no statistical significance between the groups (p>0.05). It was determined that the results of Beck Anxiety Scale and Trail Making Test were not statistically significant between the two groups (p>0.05). The difference between the two groups in terms of MOCA values was statistically significant (p<0.05). Group 1 MOCA values were found to be lower than Group 2. Conclusion: It was determined that the sleep quality was poor in men working with both short-term and long-term shifts. The decrease in BDNF, GDNF and NT-3 levels of long-term employees shows that the shift work system may cause negative effects on learning and memory. Augst 2022, 93 Pages. Keywords: Brain, Brain-Derived Neurotrophic Factor, Glial Cell Line-Derived Neurotrophic Factor, Neurotrophin 3, Shift-Work, Sleep Disorder.