Correlation of mean platelet volume (MPV) and red blood cell distribution width (RDW) with obstructive sleep apnea syndrome (OSAS) severity

The pathophysiology of OSAS entails the activation of inflammatory processes promoting oxidative stress, endothelial cell injury and dysfunction. MPV and RDW have been proposed as alternative markers for evaluating the inflammatory burden in OSAS. We aimed to investigate the correlation of MPV and RDW with OSAS severity. 90 patients underwent PSG. Patients with apnea-hypopnea index (AHI<5) were used as controls. Patients with AHI>5, were divided into mild OSAS: 5≤AHI<15, moderate OSAS:15≤AHI<30 and severe OSAS: AHI ≥30. Patients >65 years, with BMI>40, central sleep apnea syndrome, cardiovascular or other significant comorbidities were excluded. Blood sample collection occurred in a fasting state at the Sleep Laboratory one day before PSG in order to measure RDW and MPV. 64 patients were included in our study. 57 (89.1%) had OSAS (16% mild, 25% moderate, 48.4% severe AHI>5) while the remaining 7 (10.1%) were used as controls. MPV did not differ between OSAS patients and control [median (IQR) 8.5 (7.4, 9.6) vs 8.1 (7.1, 9.2), p=0.705] nor among different stages of OSAS severity [8.1 (7.1, 9.2) vs 7.9 (6.8, 10.1) vs 8.5 (7.4, 9.1) vs 8.4 (7.6, 9.7), p=0.930] for control, mild, moderate and severe OSAS respectively. RDW did not differ between OSAS patients and control [median (IQR) 14.4 (13.4, 15.3) vs 14.0 (13.5, 16.7), p=0.950] while there was no significant difference among different stages of OSAS severity [14.0 (13.5, 16.7) vs 13.9 (11.4, 14.8) vs 14.4 (14.0, 15.3) vs 14.4 (13.3, 15.6), p=0.517] for control, mild, moderate and severe OSAS respectively. Our findings suggest that there was no association between OSAS severity and MPV or RDW.