Objective: To investigate the influence of nasal continual positive airway pressure (nCPAP) on the plasma levels of thromboxane B(2) (TXB(2)), renin, angiotensin II (AT-II), endothelin 1 (ET-1), cyclic AMP (cAMP) and cyclic GMP (cGMP) and evaluate their clinical significance.
Methods: 20 patients with OSAS without cardiovascular complications and 20 nromal controls were enrolled in the study, who were monitored with PSG, and then treated with nCPAP during the second night. All the plasma parameters were measured after PSG monitoring and nCPAP management with radio-immunoassay.
Results: Before nCPAP, plasma levels of TXB(2), renin, and AT-II were higher in patients with OSAS than those in control (P < 0.05); Meanwhile, the plasma levels of ET-1, cAMP, and cAMP/cGMP were significantly higher in patients group than those in control (P < 0.01).
Conclusions: Patients with severe OSAS may have disturbances in neuro-regulation and changes in plasma level of TXB(2), renin, AT-II and ET-1, which indicates that the vasoactive substance might be related to the hypoxemia and disturbance in neuro-regulations, and might play an important role in the development of hypertension and other cardiovascular disorders. nCPAP therapy can correct the abnormalities of some vasoactive substances.