Risk factors for developing sleep-disordered breathing in patients with recent ischaemic stroke

NorAdina AT, Hamidon BB, Roslan H, Raymond AA
Correspondence: Dr Nor Adina Ahmad Tajudin, noradinatajudin2000@yahoo.com

ABSTRACT
Introduction There are several studies that reported a higher frequency of sleep-disordered breathing (SDB) among ischaemic stroke patients with increasing evidence linking SDB and cardiovascular complications. Many showed prevalence between 43 percent and 72 percent, taking the apnoea-hypopnoea index (AHI) equal to or greater than ten. The main objective of this study was to determine the frequency of SDB in recent ischaemic stroke patients admitted to Hospital Universiti Kebangsaan Malaysia (HUKM) and the relationship between SDB and known risk factors of ischaemic stroke.
Methods This was a cross-sectional, prospective study involving 28 consecutive acute ischaemic stroke patients admitted to HUKM over three months. Sleep studies were done within one to four weeks after stroke onset. Demographical data and associated risk factors were recorded and data were analysed.
Results There were 20 men and eight women, with mean age of 60.3 +/- 8.9 years. There were eight Malay, 16 Chinese and four Indian patients. The prevalence of SDB in ischaemic stroke depending on the AHI cut-off was: 92.8 percent for AHI greater than or equal to five, 78.5 percent for AHI greater than or equal to ten, 44.5 percent for AHI greater than or equal to 15, and 37.7 percent for AHI greater than or equal to 20. We discovered that diabetes mellitus and smoking history were important factors predicting significant SDB (AHI greater than or equal to 15) in recent ischaemic stroke cases.
Conclusion There was a high prevalence of SDB in recent ischaemic stroke patients in HUKM, comparable to other studies. Diabetes mellitus and smoking history were strong predictors of the occurrence of SDB after an ischaemic stroke.

Keywords: cerebrovascular accident, ischaemic stroke, polysomnography, sleep apnoea, sleep-disordered breathing, stroke
Singapore Med J 2006; 47(5): 392-399