[The effects of continuous positive airway pressure ventilation on hypersensitive C reaction protein and 8-isoprostane in patients with obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: To observe the effect of continuous positive airway pressure ventilation on hypersensitive C reaction protein (hsCRP) and 8-isoprostane in patients with obstructive sleep apnea hypopnea syndrome (OSAHS).

METHODS: A total of 78 OSAHS patients were enrolled and monitored by polysomnography (PSG) in January to March, 2013. Another 40 healthy persons were chosen as controls during the same time. According to apnea hypopnea index (AHI) and oxygen saturation, the patients were divided into mild, moderate and severe groups. Blood and urinary 8-isoprostane and hsCRP levels were detected before and after monitoring. After continuous positive airway pressure treatment for three months, blood and urinary 8-isoprostane and hsCRP were also detected in three groups.

RESULTS: (1) In OSAHS patients, blood 8-isoprostane levels before and after sleep monitoring were (273.80±55.83) ng/L and (337.18±56.28) ng/L urinary 8-isoprostane (35.65±7.08) ng/L and (48.30±14.17) ng/L, hsCRP (7.63±6.10) µg/L and (9.68±8.55)µg/L, respectively. Each parameter reached a significant difference before and after sleep (P<0.05). (2) The levels of blood CRP and urinary 8-isoprostane in the control group before sleep were (4.56±2.43) µg/L, (264.14±33.61) ng/L, (32.77±9.61) ng/L, after sleep were (4.33±2.08) µg/L, (284.27±47.51) ng/L, (31.13±8.24) ng/L. All the levels were less than those of OSAHS group (P<0.05). (3) The levels of blood 8-isoprostane in mild, moderate and severe groups after monitoring were (308.16±53.48) ng/L, (327.36±59.05) ng/L, (340.39±55.31) ng/L respectively, and urinary 8-isoprostane were (35.23±11.28) ng/L, (38.30±10.89) ng/L, (44.57±12.69) ng/L, hsCRP were (5.63±4.26) µg/L, (6.96±4.43) µg/L, (8.92±7.84) µg/L. None of these three parameters showed significant difference between the three groups (P>0.05). However, compared with the control group, blood and urine 8-isoprostane and hsCRP levels of any groups had significant differences (all P values<0.05). (3) There was no significant difference in the levels of hsCRP and 8-isoprostane after sleep between the three groups in OSAHS (P>0.05). (4) Urinary 8-isoprostane level after PSG was positively correlated with hsCRP (r=0.498, P<0.01). Either 8-isoprostane or hsCRP level was correlated with AHI (r=0.479, r=0.550; P<0.01). 8-isoprostane and hsCRP levels were positively correlated with time of blood hemoglobin oxygen saturation below 90% (r=0.413, r=0.502; P<0.01). (5) After continuous positive airway pressure treatment, the levels of 8-isoprostane and hsCRP both in blood or urine were decreased in the three groups of OSAHS patients (P<0.05).

CONCLUSIONS: Long term intermittent hypoxia in patients with OSAHS results in enhanced oxidative stress reaction and over-generated inflammatory mediators. There is a positive correlation between oxidative stress and inflammatory mediators, which promotes each other, leading to the organ dysfunction induced by hypoxia.