Does the Severity of Obstructive Sleep Apnea Have an Independent Impact on Systemic Inflammation?

Background and Objectives: This paper aims to show whether obstructive sleep apnea (OSA) severity increases the level of systemic inflammation markers regardless of body mass index (BMI) and body composition. Materials and Methods: In total, 128 patients with OSA were included in the study. Examinees were divided into two groups: one with mild OSA (apnea-hypopnea index (AHI) < 15) and one with moderate and severe OSA (AHI >= 15). Nutritional status was assessed using body mass index, body composition by dual X-ray absorptiometry. Systemic inflammation was assessed on the basis of plasma concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and serum level of C-reactive protein (CRP). Results: We found elevated mean values of the evaluated systemic inflammation markers (CRP, TNF-alpha, IL-6) in a group with AHI >= 15, although there was no statistical significance. Our research found a significant positive correlation with BMI (r = 0.633, p < 0.001), as well as with body fat percentage (r = 0.450, p = 0.024) and serum CRP values. Significant correlation was found between the plasma IL-6 concentration and body fat percentage (FM%) (r = 0.579, p = 0.003) and lean body mass (r = -0.501, p = 0.013). Multivariate regression analysis did not show any independent predictor (parameters of OSA, nutritional status, body composition) of the systemic inflammation markers. Conclusions: Neither one tested parameter (nutritional status and body composition) of the severity of OSA was identified as an independent prognostic factor for the severity of systemic inflammation in patients with OSA.