title: Cigarette smoking causes hearing impairment among Bangladeshi population.
abstract: Lifestyle including smoking, noise exposure with MP3 player and drinking alcohol are considered as risk factors for affecting hearing synergistically. However, little is known about the association of cigarette smoking with hearing impairment among subjects who carry a lifestyle without using MP3 player and drinking alcohol. We showed here the influence of smoking on hearing among Bangladeshi subjects who maintain a lifestyle devoid of using MP3 player and drinking alcohol. A total of 184 subjects (smokers: 90; non-smokers: 94) were included considering their duration and frequency of smoking for conducting this study. The mean hearing thresholds of non-smoker subjects at 1, 4, 8 and 12 kHz frequencies were 5.63 ± 2.10, 8.56±5.75, 21.06 ± 11.06, 40.79 ± 20.36 decibel (dB), respectively and that of the smokers were 7 ± 3.8, 13.27 ± 8.4, 30.66 ± 12.50 and 56.88 ± 21.58 dB, respectively. The hearing thresholds of the smokers at 4, 8 and 12 kHz frequencies were significantly (p<0.05) higher than those of the non-smokers, while no significant differences were observed at 1 kHz frequency. We also observed no significant difference in auditory thresholds among smoker subgroups based on smoking frequency. In contrast, subjects smoked for longer duration (>5 years) showed higher level of auditory threshold (62.16 ± 19.87 dB) at 12 kHz frequency compared with that (41.52 ± 19.21 dB) of the subjects smoked for 1-5 years and the difference in auditory thresholds was statistically significant (p<0.0002). In this study, the Brinkman Index (BI) of smokers was from 6 to 440 and the adjusted odds ratio showed a positive correlation between hearing loss and smoking when adjusted for age and body mass index (BMI). In addition, age, but not BMI, also played positive role on hearing impairment at all frequencies. Thus, these findings suggested that cigarette smoking affects hearing level at all the frequencies tested but most significantly at extra higher frequencies.
authors.affiliation: Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh.
authors.forename: Ahmed Faisal
authors.initials: AF
authors.lastname: Sumit
authors.affiliation: Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh.
authors.forename: Anindya
authors.initials: A
authors.lastname: Das
authors.affiliation: Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh.
authors.forename: Zinat
authors.initials: Z
authors.lastname: Sharmin
authors.affiliation: Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh.
authors.forename: Nazmul
authors.initials: N
authors.lastname: Ahsan
authors.affiliation: Nutritional Health Science Research Center, Chubu University, Kasugai, Japan; Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Ohgami
authors.affiliation: Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kato
authors.affiliation: Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh.
authors.forename: Anwarul Azim
authors.initials: AA
authors.lastname: Akhand
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001309:Auditory Threshold; D001459:Bangladesh / Q000453:epidemiology; D034381:Hearing Loss / Q000209:etiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D012907:Smoking