Tobacco Smoke Exposure during Childhood: Effect on Cochlear Physiology

Abstract

The rate of smoking in Brazil is about 18.8%. Exposure to environmental tobacco smoke is one of the major factors predisposing children to several hazardous health problems. The objective of the present research was to analyze the effect of tobacco smoke exposure during childhood on cochlear physiology by measuring the transient evoked otoacoustic emissions (TEOAE) response levels. Cotinine, the main metabolite of nicotine, was measured in 145 students’ (8–10 years old) urine. Sixty students indicated tobacco smoke exposure (TSE) (cotinine urine levels ≥ 5.0 ng/mL) and 85 did not. The evaluation of TEOAE of TSE students showed lower response levels, mainly on frequencies of 2.8 kHz on the right and left ears and 2.0 kHz on left ear and lower signal noise response levels, mainly on the 1.0 kHz and 1.4 kHz frequencies, when compared to controls that were not exposed to tobacco. The mean hearing loss in tobacco smoke exposure children was 2.1 dB SPL. These results have important implications on the damage to the cochlear structures and indicate a possible loss in hearing and hearing ability development.

Children exposed to second hand-smoke and sensorineural hearing loss

“…Moreover, TEOAEs showed lower signal to noise ratios (SNRs) at all frequency bands when the SHS group was compared to the control group (Table 6). This agreed with Durante et al, 25 that found a lower response level of TEOAEs, mainly at frequencies of 2-2.8 kHz, and also lower signal to noise ratios (SNRs), mainly at 1-1.4 kHz, in the children with SHS when compared to the non-exposed one. Also, Paschoal & Azevedo 27 stated that the reduction in TEOAEs was found at 1 kHz, similar to the present study.…”

“…SHS exposure in childhood is proposed to affect the physiology of the cochlea by distressing the outer hair cells which can be accessed through a decreased in (TEOAE) response. 25 In the current study, 64 ears of the study group had a total pass; on the other hand, there were 30%with a partial pass and 6% with failed TEOAE (Table 5). Moreover, TEOAEs showed lower signal to noise ratios (SNRs) at all frequency bands when the SHS group was compared to the control group (Table 6).…”

“…25−26 The reduction of the cochlear physiology during all period of childhood which is a serious period of the development of hearing abilities might lead to a progressive disorder of the auditory system. 25 Key et al, 13 reported that maternal smoking can affect normal fetal brain development causing auditory cognitive dysfunction.…”

Smoking, Central Adiposity, and Poor Glycemic Control Increase Risk of Hearing Impairment

“…It was previously reported that smokers were more likely to have prevalent HI (odds ratio = 1.69, 95% confidence interval (CI) = 1.31–2.17) in the population‐based Epidemiology of Hearing Loss Study (EHLS) . Higher circulating levels of reactive oxygen species or inflammatory markers and atherosclerotic changes associated with smoking may damage the cochlea or result in neurodegeneration . Other cross‐sectional population‐based studies also have reported associations between smoking and prevalent HI .…”

Exposição à fumaça do cigarro no início do período pós-natal: predisposição à dependência de drogas de abuso na adolescência

“…A PTA é um risco para a saúde não apenas para os fumantes, mas também para os fumantes passivos, principalmente para as crianças (DURANTE et al, 2013;JOYA et al, 2014). Trabalhos anteriores de nosso grupo mostram que a exposição de camundongos à PTA no início do período pós-natal induz estresse oxidativo em diferentes regiões encefálicas (TORRES et al, 2012), além de danos ao processo de mielinização no nervo óptico e diminuição das proteínas Olig-1 e proteína básica de mielina (TORRES et al, 2014).…”