Is NIDDM a risk factor for noise-induced hearing loss in an occupationally noise exposed cohort?

Little is known about what factors, other than chronic exposure to noise, predispose individuals to noise-induced hearing loss (NIHL). The current retrospective study was designed to identify risk factors for NIHL in a population of 229 men [age 55-68 (mean = 63 years)] employed at a metal assembly plant. All men had been chronically occupationally noise-exposed for approximately 30 years (> or = 89 dBA) with an average Ea noise emission level) of 104.5. The clinical examination included a pure-tone threshold audiometric evaluation, discrimination of speech in background noise [W-22 Max (> 60% indicating better hearing)], blood pressure measurement, evaluation of lifestyle (alcohol consumption, cigarette smoking, noisy hobbies) and occupational and military history. Severe NIHL was defined as > or = 65 db loss at 3, 4 or 6 kHz in at least one ear +/- 20 db threshold in the contralateral ear. History of non-insulin dependent diabetes mellitus (NIDDM) was reported by 16.4% of the 146 ...  more