title: Factors associated with hearing impairment in patients with congenital hypothyroidism treated since the neonatal period: a national population-based study.
abstract: BACKGROUND
  Untreated hypothyroidism is known to impair hearing, but little is known about the long-term hearing of patients treated for congenital hypothyroidism (CH) since the neonatal period.
  
  
  OBJECTIVE
  The purpose of this study was to assess hearing and its determinants in a population-based registry of young adult patients with CH.
  
  
  METHODS
  Self-declared hearing loss was evaluated in 1202 of the 1748 eligible patients with CH who completed a questionnaire on health status at a median age of 23.4 years. Audiograms were obtained for one third of the patients declaring hearing loss (37 of 107).
  
  
  METHODS
  Self-declared hearing loss and audiogram characteristics for patients reporting hearing impairment were measured.
  
  
  RESULTS
  These patients had a risk of self-declared hearing loss more than 3 times higher than that for the reference population (relative risk [RR] = 3.7; 95% confidence interval [CI], 2.9-4.7). Hearing impairment was diagnosed at a median age of 7.0 (25th-75th percentiles, 3.4-19.0) years, and 17% of affected patients required hearing support in early adulthood. Hearing loss was associated with the type of CH (patients with athyreosis and gland in situ were more frequently affected than those with an ectopic gland [RR = 2.61; 95% CI, 1.77-3.88]), with disease severity, as assessed by bone maturation delay at the time of diagnosis, with at least one knee epiphyseal ossification center absent in the most severe form (RR = 2.29; 95% CI, 1.39-3.79), and with other associated chronic diseases (RR = 3.64; 95% CI, 2.35-5.62). A trend for association with serum free T4 concentration at diagnosis was also observed (RR = 1.47; 95% CI, 0.96-2.23). Hearing loss was mostly bilateral (90%), mild to moderate (96%), of the sensorineural type (76%), and concerned high or very high frequencies.
  
  
  CONCLUSIONS
  Despite major improvements in prognosis, hearing loss remains a significant problem, particularly in patients with severe CH. Parents and primary care providers should be aware of this risk, because early diagnosis and intervention could improve the long-term prognosis in these patients.
authors.affiliation: Assistance Publique-Hôpitaux de Paris, Hôpital Robert Debré, Service d'Endocrinologie Diabétologie Pédiatrique, Centre de Référence des Maladies Endocriniennes Rares de la Croissance, F-75019 Paris, France.
authors.forename: Lydia
authors.initials: L
authors.lastname: Lichtenberger-Geslin
authors.forename: Sophie
authors.initials: S
authors.lastname: Dos Santos
authors.forename: Yasmine
authors.initials: Y
authors.lastname: Hassani
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Ecosse
authors.forename: Thierry
authors.initials: T
authors.lastname: Van Den Abbeele
authors.forename: Juliane
authors.initials: J
authors.lastname: Léger
mesh_terms: D000293:Adolescent; D000328:Adult; D003409:Congenital Hypothyroidism / Q000150:complications*; D059026:Diagnostic Self Evaluation; D005260:Female; D005602:France; D006304:Health Status; D006306:Health Surveys; D034381:Hearing Loss / Q000175:diagnosis* / Q000209:etiology*; D006320:Hearing Tests; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening; D011379:Prognosis; D012042:Registries; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires