Obstructive sleep apnea and biomarkers of inflammation in ischemic stroke

Medeiros CAM et al. – Interleukin–6, an atherogenic marker, shows a commensurate increase in stroke patients with obstructive sleep apnea (OSA). It is correlated with oxyhemoglobin desaturation and with desaturation index and may be a surrogate measure to evaluate continuous positive airway pressure therapy.

Methods

• Nocturnal polygraphy was performed in 50 consecutive patients with acute ischemic stroke in the first week after the event.
• Levels of inflammatory markers (IL-6, IL-1β and TNF-α) were determined from morning blood samples and comparatively analyzed between cases with and without severe OSA and with age-matched controls.

Results

• All patients with acute ischemic stroke, 31 men, mean age (64.3 ± 7.7 years), had apnea-hypopnea index (AHI) > 5 and 35 (70%) had severe OSA (AHI ≥30).
• Hypertension was more frequent in patients with severe OSA (85.7%) when compared to controls (40.0%) (P = 0.002).
• Stroke outcome, assessed by the Barthel index, tended to be more severe (P = 0.06) in cases with severe OSA.
• Patients with mild/moderate OSA and with severe OSA showed higher levels of IL-6 when compared to controls (P = 0.01 and P = 0.000, respectively).
• Among cases with acute stroke and severe OSA, IL-6 levels were correlated with lower oxyhemoglobin desaturation (r=-0.30; P = 0.001) and with the desaturation index (r = 0.15; P = 0.02).

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