Impairment of serum albumin antioxidant properties in obstructive sleep apnoea syndrome

• Published in: The European respiratory journal Vol. 31; no. 5; pp. 1046 - 1053
• Main Authors: Faure, P, Tamisier, R, Baguet, J-P, Favier, A, Halimi, S, Levy, P, Pepin, J-L
• Format: Journal Article
• Language: English
• Published: Leeds Eur Respiratory Soc 01.05.2008; Maney
• Subjects: Adult; Antioxidants - chemistry; Antioxidants - metabolism; Antioxidants - pharmacology; Biological and medical sciences; Case-Control Studies; Continuous Positive Airway Pressure; Fructosamine - blood; Glycosylation; Humans; Isoprostanes - urine; Medical sciences; Middle Aged; Oxidation-Reduction; Pneumology; Respiratory system : syndromes and miscellaneous diseases; Serum Albumin - chemistry; Serum Albumin - metabolism; Serum Albumin - pharmacology; Sleep Apnea, Obstructive - blood; Sleep Apnea, Obstructive - physiopathology; Sulfhydryl Compounds - blood; Oxidative stress; Nervous system diseases; Sleep apnea syndrome; Thiol; Respiratory disease; Albumin; protein glycation; Antioxidant; Properties; obstructive sleep apnoea; Glycation; Protein; antioxidant properties; Serum; thiols; Pneumology
• ISSN: 0903-1936; 1399-3003
• DOI: 10.1183/09031936.00062707

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 micromol x g(-1) protein), and glycation, associated with a significant increase in fructosamines (226.6+/-27 versus 286+/-44.4 micromol x 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 micromol x 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.