Abstract:

Objective To study the correlation between osteocalcin（OC）level and cognitive function in patients with obstructive sleep apnea hypopnea syndrome（OSAHS），and observe the effect of noninvasive ventilator therapy on their cognitive dysfunction. Methods Ninety ⁃eight male patients with OSAHS，confirmed by polysom⁃ nography（PSG），were enrolled in the study：41 of them with mild⁃moderate symptoms were assigned as mild⁃moder⁃ ate group and 57 of them with severe symptoms as severe group. During the same period，another forty⁃two male subjects who were confirmed without OSAHS were enrolled as controls. All the subjects completed the Epworth sleepi⁃ ness scale（ESS）and underwent Mini Mental Intelligence scale（MMSE）test. Blood samples were collected from all the subjects for measuring OC and TAOC. Twenty ⁃ eight patients with severe OSAHS were voluntarily treated with continuous positive airway pressure（CPAP）. After six months，PSG was conducted，and the levels of serum OC and TAOC were measured. Results （1）The MMSE score of OSAHS patients was（24.76 ± 2.06），and that of the control group was（28.9 ± 1.67）. The serum OC level in the OSAHS patients was（19.04 ± 8.0）ng/mL，and that in the control group was（23.21 ± 9.4）ng/mL. The level of TAOC in the OSAHS group was 6.40（5.41，7.60）U/mL， and that in the control group was 8.08（7.08，9.29）U/mL. The differences in the MMSE score and the levels of OC and TAOC were all significant between the two groups（P < 0.05）.（2）As compared with the mild⁃moderate group，the levels of OC and TAOC were significantly decreased in the severe group. None of the MMSE scores showed significant difference between the mild⁃moderate group and severe group.（3）Among the twenty⁃eight patients with severe OSAHS，there were significant differences between pre ⁃ and post ⁃ CPAP in the MMSE score［（23.71 ± 2.42）vs.（24.64 ± 2.13），P < 0.05］，and the level of TAOC［（6.13（5.10，7.02）U/mL vs. 7.34（6.80，8.90）U/mL， P < 0.05］，but there was no significant difference in the level of TAOC between pre ⁃ and post⁃CPAP［（19.98 ± 8.60）ng/mL vs.（20.77 ± 7.76）ng/mL，P > 0.05］.（4）The OC level was positively correlated with the level of TAOC， MMSE score，memory，attention，and calculation ability among those OSAHS patients. Conclusion OSAHS patients are susceptible to cognitive dysfunction，which may be related to the decreased OC. Aggregatedoxidative stress works as a factor impacting OC. Noninvasive ventilation as a therapy is conducive to alleviating the oxidative stress and the cognitive function impairment. 

Key words: