Increase in serum haptoglobin and apolipoprotein M in patients with obstructive sleep apnoea.

Obstructive sleep apnoea (OSA) is a common syndrome, which is associated with a number of medical problems that impact morbidity and mortality. Although the precise mechanisms that underlie these associations are not fully understood, previous studies have suggested that patients with OSA show elevations of several biomarkers that are associated with cardiovascular risk. This study was undertaken to identify serum proteins associated with OSA by using a proteomics technique and to examine changes in identified protein levels after continuous positive airway pressure treatment. The study participants consisted of 40 male patients (aged 40-49 years) with severe OSA and 34 male control subjects matched for age and body mass index. All subjects underwent polysomnography. Using a proteomics approach, we identified nine proteins that were differentially expressed in patients with severe OSA and controls. Three of these nine proteins, haptoglobin, paraoxonase-1 and apolipoprotein M, were quantified by using enzyme-linked immunosorbent assays, kinetic assays and by using Western blotting. Multiple regression analysis showed that haptoglobin and apolipoprotein M levels are independently related to apnoea-hypopnoea index (P < 0.01). A further study is required to determine the nature of associations between these identified proteins and OSA in a large population.

Prevalence of sleep-disordered breathing in middle-aged Korean men and women.

With many epidemiologic studies made to establish the prevalence of sleep-disordered breathing (SDB) and obstructive sleep apnea syndrome (OSAS) in Western countries, no such data have been reported in Korea. The purpose of this study was to examine the prevalence of SDB and OSAS, and their related factors in Korean adults aged 40-69 years. Among the total of 5,020 participants at the baseline examination of the Korean Health and Genome Study, a random sample of 457 men and women was studied with employment of overnight full polysomnography to determine the prevalence of SDB and OSAS. The prevalence of SDB (apnea-hypopnea index > or = 5) was 27% and 16% in men and women, respectively. When OSAS was defined by an apnea-hypopnea index > or = 5 plus excessive daytime sleepiness, its prevalence was 4.5% in men and 3.2% in women. Logistic regression analyses showed that sex, body mass index, and hypertension were closely associated with the risk of SDB. Our findings show that SDB is a common problem in the Korean adult population. Understanding and treatment of SDB may be essential in terms of intervention to reduce the risk of related medical problems.