Increased Asymmetric Dimethylarginine and Ischemia-Modified Albumin Levels in Obstructive Sleep Apnea

Abstract

BACKGROUND: Asymmetric dimethylarginine and ischemia-modified albumin are new biomarkers that are used for evaluation of ischemia and oxidative stress. The present study aimed to investigate whether serum levels of asymmetric dimethylarginine and ischemia-modified albumin are altered in subjects with obstructive sleep apnea (OSA). METHODS: A cross-sectional, clinical study was implemented on data derived from 79 subjects who underwent polysomnography. Cases were allocated into 3 groups with respect to polysomnography results: Group 1 consisted of 22 subjects without apnea, whereas Group 2 comprised 29 subjects with mild to moderate OSA, and Group 3 included 28 subjects with severe OSA. These 3 groups were compared in terms of demographic datas and polysomnographic parameters, serum levels of asymmetric dimethylarginine and ischemia-modified albumin. RESULTS: Serum levels of ischemia-modified albumin were significantly higher in Groups 2 and 3 (P = .001). Mean S-pO2 of Group 3 was notably lower than that of Groups 1 and 2 (P < .001), whereas times for S-pO2 < 90% were statistically significantly different from each other in all 3 groups (P < .001). Serum levels of asymmetric dimethylarginine in Group 3 were notably higher than those in Group 1 (P = .027). Levels of ischemia-modified albumin were correlated positively with AHI and time S-pO2 < 90% values (P = .008 and P <.001, respectively). CONCLUSIONS: Ischemia-modified albumin and asymmetric dimethylarginine were significantly higher in subjects with OSA. Furthermore, ischemia-modified albumin was independently associated with severity of OSA defined by AHI and severity of oxygen desaturation.