Association between C-reactive protein and unrecognised sleep-disordered breathing in the elderly.
Elevated levels of C-reactive protein (CRP) have been reported in patients with sleep-disordered breathing (SDB) and may represent an inflammatory marker of cardiovascular risk. However, the association of CRP with SBD in presumed healthy elderly subjects is unknown. In total, 851 (58.5% females) 68-yr-old subjects, who were free of any known cardiac or sleep disorders, were prospectively examined. Subjects underwent unattended polygraphy, and the apnoea/hypopnoea index (AHI) and oxyhaemoglobin desaturation index (ODI) were assessed. Elevated levels of CRP were found on the morning after the sleep study in patients with more severe SDB. A significant correlation was found between CRP levels, time spent at night with arterial oxygen saturation <90% and ODI. No association was found between CRP levels and AHI. After adjustments for body mass index, smoking status, hypertension, diabetes and dyslipidaemia, a significant association remained between CRP levels and ODI >10 events.h(-1). CRP levels were frequently increased in a large sample of elderly subjects free of major cardiovascular disease. CRP levels were not correlated with the AHI and the indices of sleep fragmentation; the ODI >10 events.h(-1) was the strongest predictor of raised CRP level. The present results suggest that, in the elderly, intermittent hypoxaemia may underlie inflammatory processes leading to cardiovascular morbidity.
Roche
F
F
Service de Physiologie Clinique et de l'Exercice, CHU Nord, Saint-Etienne, France. Frederic.Roche@univ-st-etienne.fr
Gaspoz
J-M
JM
Pichot
V
V
Picard-Kossovsky
M
M
Maudoux
D
D
Garcin
A
A
Celle
S
S
Sforza
E
E
Barthélémy
J C
JC
D000368:Aged; D000704:Analysis of Variance; D000886:Anthropometry; D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000276:immunology / Q000378:metabolism*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D017286:Polysomnography; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012891:Sleep Apnea Syndromes / Q000276:immunology / Q000378:metabolism*
D015415:Biomarkers; D002097:C-Reactive Protein