title: Markers of inflammatory status are associated with hearing threshold in older people: findings from the Hertfordshire Ageing Study.
abstract: BACKGROUND
  Age-related hearing loss is a common disabling condition but its causes are not well understood and the role of inflammation as an influencing factor has received little consideration in the literature.
  
  
  OBJECTIVE
  To investigate the association between inflammatory markers and hearing in community-dwelling older men and women.
  
  
  METHODS
  Cross-sectional analysis within a cohort study.
  
  
  METHODS
  The Hertfordshire Ageing Study.
  
  
  METHODS
  A total of 343 men and 268 women aged 63-74 years on whom data on audiometric testing, inflammatory markers and covariates were available at follow-up in 1995.
  
  
  METHODS
  Average hearing threshold level (across 500-4,000 Hz) of the worst hearing ear and audiometric slope in dB/octave from 500 to 4,000 Hz.
  
  
  RESULTS
  Older age, smoking, history of noise exposure and male gender (all P < 0.001) were associated with higher mean hearing threshold in the worse ear in univariate analysis. After adjustment for these factors in multiple regression models, four measures of immune or inflammatory status were significantly associated with hearing threshold, namely white blood cell count (r = 0.13, P = 0.001), neutrophil count (r = 0.13, P = 0.002), IL-6 (r = 0.10, P = 0.05) and C-reactive protein (r = 0.11, P = 0.01). None of the inflammatory markers was associated with maximum audiometric slope in adjusted analyses.
  
  
  CONCLUSIONS
  Markers of inflammatory status were significantly associated with degree of hearing loss in older people. The findings are consistent with the possibility that inflammatory changes occurring with ageing may be involved in age-related hearing loss. Longitudinal data would enable this hypothesis to be explored further.
authors.affiliation: Hearing and Balance Centre, Institute of Sound and Vibration Research, University of Southampton, Highfield, Southampton SO17 1BJ, UK. cav@isvr.soton.ac.uk
authors.forename: Carl Anton
authors.initials: CA
authors.lastname: Verschuur
authors.forename: Aphra
authors.initials: A
authors.lastname: Dowell
authors.forename: Holly Emma
authors.initials: HE
authors.lastname: Syddall
authors.forename: Georgia
authors.initials: G
authors.lastname: Ntani
authors.forename: Shirley J
authors.initials: SJ
authors.lastname: Simmonds
authors.forename: Daniel
authors.initials: D
authors.lastname: Baylis
authors.forename: Catharine R
authors.initials: CR
authors.lastname: Gale
authors.forename: Bronagh
authors.initials: B
authors.lastname: Walsh
authors.forename: Cyrus
authors.initials: C
authors.lastname: Cooper
authors.forename: Janet M
authors.initials: JM
authors.lastname: Lord
authors.forename: Avan Aihie
authors.initials: AA
authors.lastname: Sayer
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D001299:Audiometry; D001309:Auditory Threshold; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D034381:Hearing Loss / Q000097:blood*; D006801:Humans; D007249:Inflammation / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009504:Neutrophils; D009622:Noise / Q000009:adverse effects; D012907:Smoking / Q000009:adverse effects
chemical_list: D015415:Biomarkers; C508600:IL6 protein, human; D015850:Interleukin-6; D002097:C-Reactive Protein