title: Diabetes reduces auditory sensitivity in middle-aged listeners more than in elderly listeners: a population- based study of age-related hearing loss.
abstract: BACKGROUND
  Diabetes mellitus (DM) and hearing impairment are both highly prevalent in older adult populations, but how the impact of diabetes on hearing varies by age is not well-studied.
  
  
  METHODS
  The subjects were 2306 adults aged 40 to 86 years who participated in a population-based study of aging, and were divided into 2 age groups, 40-64 years and 65-86 years, for cross-sectional analysis. Air-conduction pure-tone thresholds at octave intervals from 125 to 8000 Hz were obtained. Outcomes were categorized in relation to presence or absence of DM. Hearing levels at 7 frequencies were set in the general linear model as objective variables with adjustment for confounders. Explanatory variables were age (<65 years vs. > or =65 years), DM (absence vs. presence), and interaction between age and DM.
  
  
  RESULTS
  A statistically-significant adverse effect of DM on hearing was observed. This effect varied by age at the higher frequencies. The DM-age interaction was not synergistic at any test frequencies. No significant effects of the DM-age interaction were observed below 4000 Hz. In contrast, significant reciprocal effects of the DM-by-age interaction were found at 4000 Hz and 8000 Hz. Diabetes may accordingly affect higher-frequency hearing more strongly in the younger age-bracket.
  
  
  CONCLUSIONS
  This study demonstrated that diabetes detrimentally affected hearing in community-dwelling middle-aged and elderly people, and that the effect of diabetes on higher-frequency hearing might be stronger in middle age. Screening for hearing impairment in diabetic patients may provide benefits for intervention or prevention of early presbycusis, particularly in this age group.
authors.affiliation: Department of Otorhinolaryngology, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan. yasueu@ncgg.go.jp
authors.forename: Yasue
authors.initials: Y
authors.lastname: Uchida
authors.forename: Saiko
authors.initials: S
authors.lastname: Sugiura
authors.forename: Fujiko
authors.initials: F
authors.lastname: Ando
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakashima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shimokata
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D001307:Auditory Perception; D003710:Demography; D048909:Diabetes Complications / Q000150:complications*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011304:Presbycusis / Q000150:complications* / Q000453:epidemiology; D015995:Prevalence