Decreased multidrug resistance protein 1 and increased platelet activation in obstructive sleep apnea syndrome

Abstract Introduction Obstructive sleep apnea syndrome (OSAS) is an inflammatory disease characterized by recurrent apnea and hypopnea. Multidrug resistance protein 1 (MRP1) is an anti‐inflammatory protein that protects the cell from agents caused by oxidative stress. The aim of this study was to investigate the role of MRP1 in platelet function in OSAS. Methods According to the polysomnography results, 14 patients with simple snoring, 16 with mild OSAS, 14 with moderate OSAS, and 15 with severe OSAS were included in the study. Platelet aggregations were evaluated by an aggregometer. MRP1, CD62P (P‐selectin), CD41b, and CD42b expressions were measured by a flow cytometer. Results Platelet aggregation levels were higher in the severe OSAS group than in the simple, mild, and moderate OSAS groups ( p = 0.041). On the other hand, CD42b+/MRP1+ expression was lower in the severe OSAS group than in the simple, mild, and moderate OSAS groups ( p = 0.002). MRP1 and CD42b expressions were consistent with this result ( p = 0.013, p = 0.009, respectively). A positive correlation was found between apnea/hypopnea index and platelet aggregation ( r = 0.289 p = 0.028) and a negative correlation was found between CD42b, CD42b+/MRP1+ ( r = −0.419 p = 0.001, r = −0.357 p = 0.006, respectively). Conclusion Our findings suggest that high platelet activity and low MRP1 expression contribute to inflammation in OSAS and thus may be biomarkers.