title: Cardiac troponin T in obstructive sleep apnea.
abstract: OBJECTIVE
  Obstructive sleep apnea (OSA) is associated with nocturnal angina and ST-segment depression, which are relieved by treatment with continuous positive airway pressure (CPAP). We tested the hypothesis that severe nocturnal hypoxia in patients with OSA causes myocyte necrosis as evidenced by increases in cardiac troponin T.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Cardiovascular physiology and sleep research laboratory.
  
  
  METHODS
  Fifteen male volunteers with coronary artery disease (CAD) and moderate or severe OSA (apnea-hypopnea index [AHI] > 15).
  
  
  RESULTS
  Polysomnography and measurement of serum cardiac troponin T before sleep, after 4 h of untreated OSA, and in the morning after 4 h of treatment with CPAP. The mean AHI for the group was 41 (SD 16), and the mean oxygen saturation nadir during sleep was 83% (SD 8%). All measurements of cardiac troponin T were < 0.010 ng/mL.
  
  
  CONCLUSIONS
  Despite the fact that some patients with OSA may experience nocturnal ischemia, this study shows that patients with severe OSA and coexisting CAD do not have nightly episodes of myocardial injury detectable by the current-generation cardiac troponin T assay.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic and Foundation, Rochester, MN 55905, USA.
authors.forename: Apoor S
authors.initials: AS
authors.lastname: Gami
authors.forename: Anna
authors.initials: A
authors.lastname: Svatikova
authors.forename: Robert
authors.initials: R
authors.lastname: Wolk
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Olson
authors.forename: Carolyn J
authors.initials: CJ
authors.lastname: Duenwald
authors.forename: Allan S
authors.initials: AS
authors.lastname: Jaffe
authors.forename: Virend K
authors.initials: VK
authors.lastname: Somers
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000032:analysis; D015331:Cohort Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D017286:Polysomnography; D011379:Prognosis; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000378:metabolism; D020107:Troponin T / Q000032:analysis / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D020107:Troponin T