PURPOSE:To investigate the association between plasma soluble CD40 ligand (sCD40L) and platelet-monocyte aggregates in patients with obstructive sleep apnea (OSA) and to determine whether treatment of OSA with nasal continuous positive airway pressure (nCPAP) alters this relationship.
METHODS:Twelve patients with OSA who were free of other diseases and twelve healthy controls matched for age, gender, and body mass index (BMI) had blood drawn for sCD40L and platelet-monocyte aggregates measurements by flow cytometry. A repeat assessment was obtained following 8 weeks of nCPAP therapy.
RESULTS:Subjects with OSA had significantly higher plasma sCD40L levels and exhibited elevated platelet-monocyte aggregates compared to non-apneic subjects (7.6±4.3 versus 1.7±1.1, p=0.004; and 41.3±23.7 versus 6.7±4.9, p=0.001; respectively). Both parameters correlated positively with the percentage of time spent with SpO2 <90% (r=0.69, p=0.01 and r=0.6, p=0.03; respectively). After 8 weeks of nCPAP treatment, sCD40 levels declined by 47% (p=0.003) and platelet-monocyte aggregates by 42% (p=0.002). None of the control patients showed any changes in either sCD40L or platelet-monocyte aggregates after the same duration that nCPAP therapy was administered to subjects with OSA.
CONCLUSION:OSA leads to upregulation of circulating sCD40L levels and platelet-monocyte aggregation that may account for the increased incidence of cardiovascular events in this population. Treatment with nCPAP may alleviate this risk.
CLINICAL IMPLICATIONS:These findings provide insight into the mechanisms by which sCD40L may contribute to atherothrombotic events in OSA patients.
DISCLOSURE:Morohunfolu Akinnusi, No Financial Disclosure Information; No Product/Research Disclosure Information