title: Telomere shortening in sleep apnea syndrome.
abstract: BACKGROUND
  Telomere length (TL) in circulating leukocytes relates to the chronological age of the individual but it is believed to reflect also the cumulative burden of oxidative stress and inflammation over the life-time. Shortening of TL has been reported in several chronic conditions characterized by oxidative stress and inflammation, such as diabetes and atherosclerosis. Because these conditions also occur in patients with Obstructive Sleep Apnea Syndrome (OSAS), we hypothesized that TL would be reduced in patients with OSAS.
  
  
  METHODS
  We compared TL in 256 patients with OSAS and 148 controls without OSAS. We also investigated if TL was related to the severity of OSAS, the presence of metabolic disorders and/or cardiovascular risk factors in these patients.
  
  
  RESULTS
  TL was significantly shorter in patients with OSAS than in controls (p<0.001). This difference persisted after adjustment for age, body mass index, cholesterol, triglycerides, glucose, and uric acid levels, smoking status and the presence of arterial hypertension (p=0.018). TL was not related to the severity of OSAS as assessed by the apnea-hypopnea index, nocturnal oxygen saturation and daytime sleepiness.
  
  
  CONCLUSIONS
  TL in circulating leukocytes is shorter in patients with OSAS than subjects without OSAS. The mechanism of this observation is unresolved since it appears independent of chronological age, the severity of OSAS and/or the presence of cardiovascular or metabolic alterations but the potential utility of TL as a biomarker of increased cardiovascular risk in these patients justifies further studies.
authors.affiliation: Servei de Anàlisis Cliniques, Hospital Universitari Son Dureta, C/Andrea Doria 55, 07014, Palma de Mallorca, Spain. antonia.barcelo@ssib.es
authors.forename: Antonia
authors.initials: A
authors.lastname: Barceló
authors.forename: Javier
authors.initials: J
authors.lastname: Piérola
authors.forename: Herminio
authors.initials: H
authors.lastname: López-Escribano
authors.forename: Mónica
authors.initials: M
authors.lastname: de la Peña
authors.forename: Joan B
authors.initials: JB
authors.lastname: Soriano
authors.forename: Alberto
authors.initials: A
authors.lastname: Alonso-Fernández
authors.forename: Antonio
authors.initials: A
authors.lastname: Ladaria
authors.forename: Alvar
authors.initials: A
authors.lastname: Agustí
mesh_terms: D000367:Age Factors; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000235:genetics / Q000502:physiology*; D012307:Risk Factors; D012720:Severity of Illness Index; D012891:Sleep Apnea Syndromes / Q000235:genetics / Q000503:physiopathology*; D016615:Telomere / Q000473:pathology*