title: Correlation between serum immunoglobulin G and hearing threshold among elderly subjects with age-related hearing loss.
abstract: OBJECTIVE
  This study was based on the hypothesis that suboptimal immune response and low serum immunoglobulin G (IgG) may predispose to age-related hearing loss (ARHL), and the objective was to determine the serum levels of IgG and hearing thresholds of apparently healthy elderly subjects and assess their correlation.
  
  
  METHODS
  This prospective study involved 126 participants ≥ 60 years old who were found to be free of any medical conditions. Pure-tone averages for both the speech (500-2,000 Hz) and high frequencies (3,000-8,000 Hz) and serum IgG levels were determined. Using 30 dB as cut-off for hearing loss, the correlation with serum IgG was assessed.
  
  
  RESULTS
  There were 59 males and 67 females with a mean age ± SD of 67.0 ± 2.7 years. Speech frequency hearing loss was seen in 30.2%, while high-frequency hearing loss accounted for 74.6%. In the speech frequencies, the mean ± SD of serum IgG among subjects with normal hearing was 11.3 ± 3.9 g/l, while among those with hearing loss it was 8.3 ± 3.3 g/l (p = 0.01). In the high frequencies, the mean ± SD values of serum IgG among the subjects with normal hearing was 11.1 ± 2.3 g/l, while among those with hearing loss it was 8.7 ± 1.9 g/l (p = 0.01).
  
  
  CONCLUSIONS
  Low serum IgG may be a contributory factor to the development of ARHL among the elderly. However, a longitudinal study involving intervention with immunoglobulin supplementation may further confirm this role.
authors.affiliation: Department of Otorhinolaryngology, College of Medicine, University of Ibadan, Ibadan, Nigeria. akeemlasisi@gmail.com
authors.forename: Akeem Olawale
authors.initials: AO
authors.lastname: Lasisi
authors.forename: Fatai A
authors.initials: FA
authors.lastname: Fehintola
authors.forename: Oyindamola Bidemi
authors.initials: OB
authors.lastname: Yusuf
authors.forename: Oladapo O
authors.initials: OO
authors.lastname: Olayemi
mesh_terms: D000368:Aged; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D016014:Linear Models; D008297:Male; D011304:Presbycusis / Q000175:diagnosis / Q000276:immunology* / Q000503:physiopathology*; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D007074:Immunoglobulin G