Sleep disordered breathing and mortality: eighteen-year follow-up of the Wisconsin sleep cohort.
BACKGROUND
Sleep-disordered breathing (SDB) is a treatable but markedly under-diagnosed condition of frequent breathing pauses during sleep. SDB is linked to incident cardiovascular disease, stroke, and other morbidity. However, the risk of mortality with untreated SDB, determined by polysomnography screening, in the general population has not been established.


METHODS
An 18-year mortality follow-up was conducted on the population-based Wisconsin Sleep Cohort sample (n = 1522), assessed at baseline for SDB with polysomnography, the clinical diagnostic standard. SDB was described by the number of apnea and hypopnea episodes/hour of sleep; cutpoints at 5, 15 and 30 identified mild, moderate, and severe SDB, respectively. Cox proportional hazards regression was used to estimate all-cause and cardiovascular mortality risks, adjusted for potential confounding factors, associated with SDB severity levels.


RESULTS
All-cause mortality risk, adjusted for age, sex, BMI, and other factors was significantly increased with SDB severity. The adjusted hazard ratio (HR, 95% CI) for all-cause mortality with severe versus no SDB was 3.0 (1.4,6.3). After excluding persons who had used CPAP treatment (n = 126), the adjusted HR (95% CI) for all-cause mortality with severe versus no SDB was 3.8 (1.6,9.0); the adjusted HR (95% CI) for cardiovascular mortality was 5.2 (1.4,19.2). Results were unchanged after accounting for daytime sleepiness.


CONCLUSIONS
Our findings of a significant, high mortality risk with untreated SDB, independent of age, sex, and BMI underscore the need for heightened clinical recognition and treatment of SDB, indicated by frequent episodes of apnea and hypopnea, irrespective of symptoms of sleepiness.
Young
Terry
T
Department of Population Health Sciences, University of Wisconsin-Madison, Madison, WI, USA. tbyoung@wisc.edu
Finn
Laurel
L
Peppard
Paul E
PE
Szklo-Coxe
Mariana
M
Austin
Diane
D
Nieto
F Javier
FJ
Stubbs
Robin
R
Hla
K Mae
KM
D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality; D002423:Cause of Death; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D016016:Proportional Hazards Models; D012306:Risk; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000175:diagnosis / Q000401:mortality*; D020521:Stroke / Q000401:mortality; D016019:Survival Analysis; D014922:Wisconsin