Cardiac troponin T in obstructive sleep apnea.
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.
Gami
Apoor S
AS
Division of Cardiovascular Diseases, Mayo Clinic and Foundation, Rochester, MN 55905, USA.
Svatikova
Anna
A
Wolk
Robert
R
Olson
Eric J
EJ
Duenwald
Carolyn J
CJ
Jaffe
Allan S
AS
Somers
Virend K
VK
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*
D015415:Biomarkers; D020107:Troponin T