Correlation between the Friedman Staging System and the Upper Airway Volume in Patients with Obstructive Sleep Apnea
Objectives: This study was designed to evaluate the correlation between computed tomography (CT) findings and data from the physical examination, such as Friedman Staging System (FSS) in patients with obstructive sleep apnea (OSA).
Methods: A retrospective study by reviewing the medical records of 33 patients (19 males and 14 females), with body mass index (BMI) of 30.38 kg/m2, and mean age of 49.35 years. Among them, 14 had severe, 7 moderate, 7 mild OSA, and 5 subjects were healthy.
Results: A positive relationship by Fisher exact test between the FSS and Apnea-Hypopnea Index (AHI; p = 0.011) and between Standard Evaluation Framework (SEF) and BMI (p = 0.012) was found. There was no correlation between age (p = 0.55) and gender (p = 0.53) with the FSS. Patients were divided in two groups according to the SEF. Group A patients contained FSS I and II and group B FSS III and IV. The analysis of variance (ANOVA) test comparing the volume between the two groups got p = 0.018.
Conclusions: On the basis of the methodology and sample used, the conclusion is that FSS and volume of upper airway show inverse relationship and are useful in analyzing the mechanisms of airway collapse in patients with OSA.
Keywords: upper airway, obstructive sleep apnea, cone beam computed tomography, Friedman Staging System.