Plasma Levels of Interleukin 2 (IL-2) Associated with Hearing Loss Evaluation in the Elderly.

CONTEXT: Presbycusis can be mediated by the effects of inflammatory processes on the auditory system, and these aging biological mechanisms remain poorly studied. AIMS: The aim of this study was to determine whether plasma biomarkers are associated with hearing disorders caused by aging in the elderly. SETTINGS AND DESIGN: Cross-sectional study with 106 participants in the Active Aging Project, 93 (88%) females and 13 (12%) males, with an average age of 70 years. METHODS AND MATERIAL: Audiological evaluation was performed with pure tone audiometry and collection of peripheral blood for the measurement of plasma levels of interleukins 2, 4, 6, and 10, tumor necrosis factor-α, and interferon-γ by means of flow cytometry. STATISTICAL ANALYSIS USED: The SPSS (v.0, SPSS Inc., Chicago, USA) was used for the analysis of the data obtained. For all data analyzed, the significance level adopted was P < 0.05 and 95% confidence interval. RESULTS: There were statistically significant correlations between male and IL-2 (P = 0.031; rs = 0.210), mean II of the right ear (P = 0.004; rs = 0.279), longer in years (P = 0.002; rs = 0.307) and in hours (P = 0.004; rs = 0.281) of noise exposure also in males. CONCLUSIONS: In the present study, there was an association between the male gender and higher plasma levels of IL-2, an increase in the average hearing in the right ear, and greater time in years and hours of exposure to noise. There was a predominance of mild sensorineural hearing loss and worsening of hearing related to age, characteristics of presbycusis.

Association between polymorphism of tumor necrosis factor alpha (tnfα) in the region -308 g/a with tinnitus in the elderly with a history of occupational noise exposure.

CONTEXT: Tinnitus is a common disorder that occurs frequently across all strata of population and has an important health concern and is often associated with different forms of the hearing loss of varying severity. AIMS: To investigate the association between the polymorphism of tumor necrosis factor alpha (TNFα) in the region -308 G/A with the susceptibility to tinnitus in individuals with the history of exposure to occupational noise. SETTINGS AND DESIGN: This was a cross-sectional study with a sample of 179 independent elderly people above 60 years of age. MATERIALS AND METHODS: Information on exposure to occupational noise was obtained by interviews. Audiological evaluation was performed using pure tone audiometry and genotyped through polymerase chain reaction by restriction fragment length polymorphism. STATISTICAL ANALYSIS USED: Data were analyzed using the chi-square test and the odds ratio (OR), with the significance level set at 5%. RESULTS: Among elderly with tinnitus (43.01%), 33.76% had a history of exposure to occupational noise. A statistically significant association was found between genotype frequencies of the TNFα gene in the -308 G/A region and the complaint of tinnitus (P = 0.04 and χ2 = 4.19). The elderly with the G allele were less likely to have tinnitus due to occupational noise exposure when compared to those carrying the A allele (OR = 2.74; 95% CI: 1.56-4.81; P < 0.0005). CONCLUSION: This study suggests an association between the TNFα with susceptibility to tinnitus in individuals with a history of exposure to occupational noise.

Interleukin-1ß gene polymorphism and hearing loss related to the history of occupational noise exposure in Brazilian elderly.

Hearing loss is the most common sensory impairment in older people, and may have social and psychological consequences, such as social isolation, frustration and depression. Noise-induced hearing loss (NIHL) is an interaction of both genetic and environmental factors. Some studies have led to the identification of possible NIHL susceptibility genes. The aim of the present study was to investigate whether the polymorphism of the interleukin (IL)-1ß gene at position + 3954 was associated with complaints of hearing loss due to occupational exposure. The sample was composed of elderly people with hearing loss (age ≥ 60 years) divided into two groups: 99 with occupational exposure to noise and 193 without exposure. Information on occupational exposure to noise was obtained through interviews using a semi-structured questionnaire. Hearing acuity was measured from 500 to 6000 Hz and the IL-1ß genotype was obtained by the polymerase chain reaction- restriction fragment length polymorphism technique. Differences in allelic and genotypic frequencies, and the association between genotypic frequencies and complaints of hearing loss due to occupational exposure, were analyzed by the Chi-square test at the 5% significance level. Fifty-one percent of the elderly were homozygous for the ancestral allele (C), 17.2% were homozygous for the polymorphic allele (T) and 31.8% were heterozygous. The frequency was found to be 67-33% C to allele T. There was no significant association between polymorphism in gene IL-1ß and hearing loss associated with occupational exposure (χ2 = 0.538; P = 0.676). No association was found with the polymorphism of the IL-1ß +3954 C/T gene and hearing loss associated with the occupational noise exposure history.