Evidence of associations between brain-derived neurotrophic factor (BDNF) serum levels and gene polymorphisms with tinnitus

Background: Brain-derived neurotrophic factor (BDNF) gene polymorphisms are associated with abnormalities in regulation of BDNF secretion. Studies also linked BDNF polymorphisms with changes in brainstem auditory-evoked response test results. Furthermore, BDNF levels are reduced in tinnitus, psychiatric disorders, depression, dysthymic disorder that may be associated with stress, conversion disorder, and suicide attempts due to crises of life. For this purpose, we investigated whether there is any role of BDNF changes in the pathophysiology of tinnitus. Materials and Methods: In this study, we examined the possible effects of BDNF variants in individuals diagnosed with tinnitus for more than 3 months. Fifty-two tinnitus subjects between the ages of 18 and 55, and 42 years healthy control subjects in the same age group, who were free of any otorhinolaryngology and systemic disease, were selected for examination. The intensity of tinnitus and depression was measured using the tinnitus handicap inventory, and the differential diagnosis of psychiatric diagnoses made using the Structured Clinical Interview for Fourth Edition of Mental Disorders. BDNF gene polymorphism was analyzed in the genomic deoxyribonucleic acid (DNA) samples extracted from the venous blood, and the serum levels of BDNF were measured. One-way analysis of variance and Chi-squared tests were applied. Results: Serum BDNF level was found lower in the tinnitus patients than controls, and it appeared that there is no correlation between BDNF gene polymorphism and tinnitus. Conclusions: This study suggests neurotrophic factors such as BDNF may have a role in tinnitus etiology. Future studies with larger sample size may be required to further confirm our results

Association among tenascin-C and NT-proBNP levels and arrhythmia prevalence in heart failure

Purpose: Tenascin-C (TN-C) and amino-terminal fragment of the B-type natriuretic peptide (NT-proBNP) are the important predictors in prognosis of heart failure (HF). The aim of this study was to analyze the relationship of TN-C and NT-proBNP levels with the frequency and severity of ventricular arrhythmia. Materials and Methods: Our study included 107 HF patients with EF < 45%. According to Holter analysis, the patients were divided into two groups as malignant arrhythmia group (n=29) with Lown Class 4a and 4b arrhythmia and benign arrhythmia group(n=78) with Lown Class 0-3b arrhythmia. The groups were compared with respect to levels of TN-C and NT-proBNP. The relationship of TN-C and NT-proBNP levels with frequency of ventricular premature beat (VPB) was also analyzed. Findings: NT-proBNP (5042.1±1626 versus 1417.1±1711.6 pg/ml) and TN-C (1089±348.6 versus 758.5±423.9 ng/ml) levels were significantly higher in the malignant arrhythmia group than that of the benign arrhythmia group (