Relationship Between Serum Asymmetric Dimethylarginine Level and Obstructive Sleep Apnea Syndrome Severity

Aim: The repetitive hypoxemia can induce oxidative stress mechanisms. Oxidative stress increases serum asymmetric dimethylarginine (ADMA) levels in patients with obstructive sleep apnea syndrome (OSAS). To investigate the relationship between serum levels of ADMA and OSAS severity. Methods: 330 patient’s records, who underwent overnight poly-somnography (PSG) were retrospectively examined. The patients who had an abnormal serum glucose, lipid, thyroid, renal and liver function tests levels, had excluded. 72 patients had participating criteria. Patients were categorized into five groups according to apnea/hipopnea index (AHI). Measurement of ADMA levels were performed by ELISA kit. Results: The mean age was 44,19 ± 14,24 years. 31,9 % of the patients were female. Patients in normal group, severe, medium, mild and positional–REM dependent OSAS group were 26,4%, 25%, 6,9 %, 16,7% and 25%; respectively. A significant positive correlation was found between AHI and ADMA (r= 0,483; p<0,001). Appropriate cut-off criterion was set at 1,39 for ADMA. Sensitivity for this value was 73,58 % (95 % Confidence Interval (CI): 61,71- % 85,45 %) and specificity was 94,74 % (95 % CI: 84,70- % to 100%). Accuracy or correct classification rate was found to be 79,17 %. The positive predictive value was 97,5 % and negative predictive value was 56,25 %. The positive likelihood ratio (LR +) was 13,98 (LR + > 10) and the negative likelihood ratio was (LR-) 0,28 (R- <1). Conclusions: ADMA was found to be a strong and good diagnostic tool among patients with normal levels for glucose, lipid, TSH, creatinine and liver function tests.