Effects of Obstructive Sleep Apnea with Intermittent Hypoxia on Platelet Aggregability

Abstract

Aim:Obstructive sleep apnea (OSA) is a risk factor for cardiovascular diseases. Platelets play key roles in the development of atherothrombosis. Several studies assessing platelet activation in patients with OSA have been published; however, there have been only a few studies with a small number of patients with OSA investigating platelet aggregability, which evaluates platelet aggregation more directly than the platelet activation status. We aimed to investigate the effects of OSA and nasal continuous positive airway pressure (nCPAP) therapy, a well-established treatment for OSA, on platelet aggregability. Methods and Results: We examined 124 consecutive patients with snoring in whom the 3% oxygen desaturation index (3%ODI), a severity marker of OSA, and ADP-and collagen-induced platelet aggregability measured with the optical aggregometer were analyzed. ADP-induced platelet aggregability was increased more in patients with moderate-to-severe OSA (3%ODI 15) than in patients with non-to-mild OSA (p 0.029). In multiple linear models, 3%ODI significantly contributed to increased platelet aggregability induced by both ADP and collagen among 59 subjects with one or more risk factors for vascular diseases, such as smoking, hypertension, diabetes mellitus or hyperlipidemia. In 23 patients treated by nCPAP, collagen-induced platelet aggregability was ameliorated on Day 90, compared to at the baseline. Conclusion: The severity of OSA significantly contributed to platelet aggregability, which was improved by nCPAP treatment partially at three months.

Complete Blood Count Alterations after Six Months of Continuous Positive Airway Pressure Treatment in Patients with Severe Obstructive Sleep Apnea

“…Adenosine diphosphate-induced platelet aggregability increased significantly in patients with moderate-to-severe OSA compared to that in controls; CPAP treatment improves platelet aggregability in these patients. 24 Similar to our results one study found that 6 months of CPAP therapy significantly reduced MPV values in patients with severe OSA. 15 The decreased MPV could be explained by decreased hypoxia and inflammation, as postulated in that study, which could help to decrease the frequency of cardiovascular complications in OSA patients.…”

FAK regulates platelet extravasation and tumor growth after antiangiogenic therapy withdrawal

“…However, lowering platelet numbers in patients with cancer requires careful titration, as thrombocytopenia can easily lead to life-threatening bleeding complications. Although platelet function and numbers can change under hypoxic conditions (27)(28)(29)55), their role in tumor hypoxia, especially with regard to antiangiogenic therapy-induced hypoxia, is not well understood. We showed that increased platelet infiltration after withdrawal of antiangiogenic therapy was dependent on expression of FAK in platelets.…”

“…We and others have shown that platelets enhance tumor growth (19,23,26), chemoresistance (20), and metastasis (21,22). Although platelet number and function can be altered by hypoxia (27)(28)(29), the functional effects of hypoxia in the tumor microenvironment on platelets are unknown. Therefore, we examined whether platelet infiltration into the tumor microenvironment could contribute to tumor growth following cessation of antiangiogenic therapy.…”

Effect of Continuous Positive Airway Pressure Treatment on Hemograms of Patients with Severe Obstructive Sleep Apnea in the Lack of Comorbidities

“…CPAP relieves airway obstruction and reduces hypoxia and inflammation [34]. CPAP treatment decreases platelet aggregability [35]. Several studies demonstrated the increase in blood viscosity before and the decrease after CPAP treatment [36,37].…”