Influence of continuous positive airway pressure therapy to retinal binding protein in urine of patients with obstructive sleep apnea hypopnea syndrome

Abstract

Objective To study the influence of continuous positive airway pressure(CPAP)therapyto the retinal binding protein(RBP)in urine of patients with obstructive sleep apnea hypopnea syndrome (OSAHS).Methods RBP in urine of 60 patients with OSAHS(OSAHS group)were determined when before CPAP therapy,after one day with CPAP therapy and after seven days with CPAP therapy resPectively.Thirty healthy persons(control group)were also studied,and the results were compared.Results Before CPAP therapy,the urine level of RBP,apnea-hypopnea index(AHI),the longest oxygen-reduction period and the highest scope of oxygen-reduction of OSAHS group were higher than those of control group (all P<O.0 1).The average pulse oxygen saturation(SpO2)of OSAHS group was lower than that of control group(P<O.01).RBP level in urine,AHI,the longest oxygen-reduction period and the highest extent of oxygen-reduction of after one-day with CPAP therapy were lower than those of before CPAP therapy,and SpO2 of after one-day with CPAP therapy was higher than that of before CPAP therapy in OSAHS group (all P<0.01).RBP level in urine,AHI,the longest oxygen-reduction period and the highest extent of oxygen-reduction of after seven days with CPAP therapy were much better than those of after one-day CPAP therapy in OSAHS group(P<0.05 or P<0.01).There was no significant difference between the urine level of RBP after seven days with CPAP therapy in OSAHS group and control group.Pearson correlation analysis revealed that RBP level in urine showed positive correlation with AHI values,the longest oxygenreduction period and the highest extent of oxygen-reduction(r=0.896,0.875,0.772,P<0.01),and showed Regative correlation with average SpO2(r=-0.638,P<O.01).Conclusion There is a significant relationship between the urine level of RBP and OSAHS,CPAP can improve low oxygen state and the urine level of RBP. Key words: Continuous positive airway pressure; Obstructive sleep apnea hyponea syndrome; Retinol binding protein