The platelet-lymphocyte ratio as a marker of the severity of the obstructive sleep apnea-hypopnea syndrome: fact or fiction?

Abstract

Systemic inflammation and oxidative stress are two mechanisms in the pathophysiology of the obstructive sleep apnea-hypopnea syndrome (OSAHS). The role of the platelet-lymphocyte ratio (PLR) as an indicator of inflammation is controversial. The aim of this study was to evaluate the relation between the PLR and the severity of OSAHS. We retrospectively analyzed the medical records of 130 patients referred for suspicion of OSAHS. According to the results of respiratory polygraphy, we classified the patients in primary snorers (Apnea-Hypopnea Index (AHI) < 5), minimal OSAHS (5 ≤ AHI < 15), mild OSAHS (15 ≤ AHI < 30) and severe OSAHS (AHI ≥ 30). We selected 62 files. The mean age of the population of study (26 males /36 females) was 51.2 ± 11.75 years. In this population, 21% were primary snorers, 35.5%, 17.7% and 25.8% had respectively minimal, mild and severe OSAHS. The AHI was significantly correlated to the PLR (p<0,001; r=0,431) but not to the CRP rate (p = 0.422). The PLR in patients with severe OSAHS (121.84 ± 28.39) was significantly higher than in primary snorers (94.37 ± 40.84; p=0.042) and patients with minimal OSAHS (100.22 ± 28.73; p=0.027). Using a linear regression including cofounding factors the PLR was independently associated to the AHI (p=0,003). The PLR is a new inflammatory marker allowing to better evaluate the severity of the OSAHS than the CRP.