ABSTRACT
Objectives : The present study tried to investigate the plasma levels of endothelial damage parameters and fibrinolysis-inhibiting enzyme plasminogen activator inhibitor type-1 (PAL-1) as possible risk factors related to obstructive sleep apnea syndrome (OSAS)-induced cardiovascular complication and as a trial to define an appropriate screening parameter for early detection of OSAS adult patients at risk of cardiovascular complications.
Patients & Methods : The study included 60 patients allocated into four groups (n = 15) : OSA patients with and without ischemic heart disease (IHD) and OSA patients with hypertension (HT) and patients with IHD but without OSA and 15 healthy volunteers (control group). All patients underwent complete otorhinolaryngologic examination and evaluation of daytime sleepiness using the Epworth Sleepiness Scale (ESS); an ESS Score >10 was used to confirm the presence of OSAS. Blood pressure (BP) was estimated to calculate the mean arterial BP (MAP); then Pulse oximetry was performed for determination of the frequency of desaturation episodes and the lowest Sa02%. All patients and controls gave fasting blood samples for ELISA estimation of plasma levels of von Willebrand factor (vWF), soluble tissue factor (sTF), PAI-1 and d-dimer.
Results : Mean ESS score was significantly higher in patients with complicated OSAS compared to those had OSAS only. Patients with OSAS+IHD had significantly higher frequency of desaturation episodes compared to those with OSAS+HT or OSAS only, but the lowest SaO2 saturation was non-significantly different between OSAS patients. Mean plasma levels of studied parameters were significantly higher in patients compared to control levels. Mean plasma levels of PAJ-1 and vlAT were significantly higher in patients with complicated OSAS compared to thuse with uncomplicated OSAS or IHD that showed nonsignificant difference. Plasma levels of d-Dimer in OSAS+IHD patients were significantly higher compared to the other patients' groups with nonsignificant difference between these groups. Plasma sTF levels were significantly higher in patients with complicated versus those with uncomplicated OSAS with significantly higher levels in patients with OSAS+IHD compared to those with OSAS+HT. There was a positive significant correlation between plasma levels of PAI-1 and vWF estimated in OSAS patients and the severity of OSAS manifested as ESS scores and number of desaturation episodes. However, all estimated parameters showed a negative correlation with the lowest Sa02 saturation recorded in OSAS patients, such correlation was significant with PAI-1 and vWF levels but was nonsignificant with d-Dimer and sTF levels. There was a positive significant correlation between the presence of OSAS-induced cardiovascular complications and estimated levels of the four parameters. Regression analysis defined plasma PAI-1 and vWF levels as the most significant predictors for occurrence of complications. These results were confirmed using ROC curve analysis that defined plasma PAI-1 as a highly specific predictor for occurrence of cardiovascular complications (AUC=0.857) followed by plasma vWF (AUC=0.839).
Conclusion : In conclusion, OSAS in adults could be considered as one of cardiovascular risk factors attributed to associated antifibrinolytic activity and estimation of PAI-1 could be used as a specific predictor for the probability of developing such complications in OSAS patients
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