Platelet indices in obstructive sleep apnea: the role of mean platelet volume, platelet distribution widht and plateletcrit

Introduction: Because studies report controversial findings of mean platelet volume (MPV) and platelet distribution width (PDW), we aimed to investigate platelet indices in patients with obstructive sleep apnea (OSA). Materials and Methods: One hundred seventy three patients with OSA and 43 control subjects included in analyses. Patients with an apnea-hypopnea index (AHI) >= 5 were considered to have OSA and an AHI < 5 were considered as control. Platelet indices (MPV, PDW, plateletcrit) were obtained from routine analysis of blood samples using an automated blood cell counter. Results: Among platelet indices, only PDW was higher in patients with OSA, especially in severe OSA when compared to control group (16.80 +/- 0.56 vs. 16.21 +/- 1.51, p= 0.015 and 16.82 +/- 0.06 vs. 16.21 +/- 1.51, p= 0.014, respectively). Correlation analysis showed a significant but a weak correlation between the PDW and AHI (r= 0.161, p= 0.018) and the PDW and the desaturation index (r= 0.171, p= 0.016). The ROC curve analysis showed that the optimal cut-off value, distinguishing patients with OSA from those in control group, for PDW was 16.62 (sensitivity 57.8%, specificity 58.1%, AUROC 0.60, p= 0.042). After the exclusion of patients with comorbid diseases (cardiovascular diseases, diabetes mellitus and chronic inflammatory diseases), we also found weak but a significant correlation between PDW and AHI (r= 0.179, p= 0.040). Conclusion: In conclusion, among the platelet indices, only PDW was found to be higher in patients with OSA, especially in severe OSA. PDW was also correlated with apnea-hypopnea index and oxygen desaturation index.