Objective: This study aimed to detect serum level of glucose regulated protein 78(GRP78) in patients with obstructive sleep apnea(OSA) and explore the relationship between endoplasmic reticulum stress and the pathophysiology of OSA.
Methods: A total of 91 patients with OSA were enrolled in this study, including 30 mild, 28 moderate and 33 severe. The other 27 obese subjects were of age, gender and BMI matched group. Eleven moderate or severe OSA patients were administrated with continuous positive airway pressure (CPAP) treatment for 24 hours. Polysomnography, apnea hypopnea index (AHI), lowest arterial oxygen saturation(SaO2) and percentage of time spent at SaO2 below 90% (SIT90) were measured before and after sleep. Serum GRP78 was measured by ELISA.
Results: The expression of GRP78 in mild(3.42±0.97)μg/L, moderate(2.67±1.14)μg/L and severe(2.62±1.11)μg/L OSA groups was significantly higher than in control group(1.75±0.41)μg/L (P<0.05). The GRP78 level in mild OSA group was significantly higher than either moderate or severe OSA group (P<0.05). After 24 h treatment of CPAP, serum GRP78 level decreased significantly [(1.77±0.39)μg/L vs(2.84±0.39)μg/L; P<0.05].
Conclusions: Endoplasmic reticulum stress involves in the pathophysiology of patients with OSA. Higher GRP78 level in mild OSA patients suggests that endoplasmic reticulum related protein GRP 78 might rise then fall during exacerbation of OSA.