Relationshiop between ApneaHypopnea Index and Red Cell Distrıbution Witdh in Patients with Obstructive Sleep Apnea Syndrome

Abstract

Obstructive Sleep Apnea Syndrome (OSAS) is the most common sleep disordered. In Spain, 3-6% of the population have symptoms of snore with 24-26% of them were above AHI ≥5 and were diagnosed with OSAS [1]. OSAS is characterized by recurrent partial or complete upper airway obstruction resulting in a hypoxia-reoxygenation cycle and arousals during sleep.Hypoxia, the main factor in thepathogenesis, leads to increased hypercapnia and intrathoracic pressure, activation of the sympathetic nervous system, deterioration of cerebral blood flow, elevation of blood pressure and disturbance of sleep. This results inadequate sleep, abnormal motor activity, headache and fatigue [2]. Because of all these metabolic changes, endothelial dysfunction occurs and there is an increased risk of cardiovascular and cerebrovascular events.Tachycardia or rhythm disturbances may occur during sleep [3]. PSG is the gold standard test in OSAS diagnosis. The disease grade is classified according to the AHI values in the polysomnography report. Thosewith AHI ≤ 5 areconsidered as simplesnoring, AHI: 5-14.9 aremild OSAS, thosewith AHI: 15-29.9 aremoderate OSAS, thosewith AHI ≥30 are severe OSAS [4].RDW shows irregularities between the shapes of erythrocytes.Oxidative stress caused by hypoxia causes irregularity in erythrocyte morphology. In systemic diseases such as iron deficiency anemi, folic acid deficiency, vitamin B12 deficiency and chronic liver disease, RDW levels increase because of oxidative stress [5]. High RDW values are an important biomarker of cardiovascular mortality and morbidity risk, before myocardial infarction [6,7]. Given the inflammatory nature of OSAS, it is thought to be associated with RDW.The aim of this study was to evaluate the association between RDW and AHI in patients with OSAS and to determine whether RDW could be a predictor of disease severity before PSG.