title: Iris pigmentation and susceptibility to noise-induced hearing loss.
abstract: The purpose of this retrospective study is to examine the possible association between iris pigmentation and susceptibility to noise-induced hearing loss in 2407 noise-exposed workers. The workers were between 16 to 65 years of age and were exposed to 2 to 42 years of work-related noise. Results demonstrated that dark-eyed workers presented a greater percentage of normal pure-tone thresholds than fair-eyed workers. Fair-eyed workers had threshold averages of 25.1 dB (right ear) and 26.0 dB (left ear) at 3, 4, and 6 kHz, which were significantly worse than workers with dark irises, with threshold averages of 15.8 dB and 17.2 dB in the right and left ear, respectively (p<0.01). Fair-eyed workers with less than 10 years of noise exposure had the same audiometric pattern as the dark-eyed workers exposed for more than 10 years. Workers not exposed to noise did not present significant differences in their audiometric pattern as a function of eye colour. These results suggest that iris pigmentation may be an additional indication of susceptibility to noise-induced hearing loss.
authors.affiliation: Department of Ophthalmo/Otolaryngology and Graduate Program in Public Health, State University of Campinas/UNICAMP, Sao Paulo, Brazil.
authors.forename: E A
authors.initials: EA
authors.lastname: Da Costa
authors.forename: J C
authors.initials: JC
authors.lastname: Castro
authors.forename: M E G
authors.initials: ME
authors.lastname: Macedo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D015415:Biomarkers; D003430:Cross-Sectional Studies; D004198:Disease Susceptibility; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000209:etiology*; D006801:Humans; D007498:Iris; D008297:Male; D008875:Middle Aged; D009623:Noise, Occupational / Q000009:adverse effects; D016273:Occupational Exposure / Q000009:adverse effects; D010857:Pigment Epithelium of Eye; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D015415:Biomarkers