RT Journal Article SR Electronic T1 Impairment of serum albumin antioxidant properties in obstructive sleep apnoea syndrome JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 1046 OP 1053 DO 10.1183/09031936.00062707 VO 31 IS 5 A1 P. Faure A1 R. Tamisier A1 J-P. Baguet A1 A. Favier A1 S. Halimi A1 P. Lévy A1 J-L. Pépin YR 2008 UL http://erj.ersjournals.com/content/31/5/1046.abstract AB Antioxidant counteraction of oxidative stress has been poorly explored in obstructive sleep apnoea (OSA). Serum albumin is a major antioxidant agent and structural modifications induced by glucose or free radicals impair its antioxidant properties. The aim of the present study was to compare antioxidant capacities and structural changes of albumin in nonobese OSA patients and healthy volunteers. Albumin structural changes were studied by quenching of fluorescence in the presence of acrylamide. Albumin thiols and fructosamines, reflecting oxidation- and glycation-induced changes in serum albumin, respectively, were assessed. Albumin structural changes were demonstrated by a significant decrease in quenching of fluorescence in OSA patients. Oxidation, resulting in a significant decrease in thiol groups (3.7±0.7 versus 2.3±0.4 μmol·g−1 protein), and glycation, associated with a significant increase in fructosamines (226.6±27 versus 286±44.4 μmol·L−1), were found when comparing healthy volunteers with OSA patients. There was a significant relationship between both parameters and sleep apnoea severity. After continuous positive airway pressure intervention, albumin thiol groups were reassessed in seven of the 16 OSA patients and increased significantly from 2.25±0.39 to 2.79±0.31 µmol·g−1 protein. Obstructive sleep apnoea patients demonstrated a reduction in serum albumin antioxidant properties that may aggravate oxidative stress and, thus, contribute to cardiovascular and metabolic morbidities.