The expression of macrophage migration inhibitory factor in obstructive sleep apnea hypopnea syndrome and its injury to endothelial cells

Abstract

Objective: To study the expression of macrophage migration inhibitory factor (MIF) in obstructive sleep apnea hypopnea syndrome (OSAHS) and its injury to endothelial cells. Methods: According to the PSG test results, subjects who were the first time to take PSG examination without treatment (n=71) were divided into a control group (n=20), a mild OSAHS group (n=19), a moderate OSAHS group (n=15) and severe OSAHS group (n=17). For each patients, 4 ml fasting peripheral blood was obtained when PSG was finished around 6: 30 in the next morning, and the MIF level in plasma was detected with the ELISA method. Peripheral blood mononuclear cells (PBMC) from the control group and the severe OSAHS patients were cocultured with umbilical vein endothelial cells (HUVEC) for 72 hours. The apoptosis of HUVEC was detected by flow cytometry, while ET-1, NO, sICAM-1 and IL-6 in the supernatants were measured with the ELISA method. Results: The plasma level of MIF in the control group and the mild, the moderate, and the severe OSAHS patients was (26±8), (28±9), (31±14), (39±15) ng/ml, respectively (F=15.65, P<0.001), and it was higher in the severe OSAHS group as compared to the control group(P<0.01). The level of MIF was associated positively with the apnea hypoventilation index (AHI, r=0.365, P=0.008) and the oxygen index reduction (ODI, r=0.308, P=0.308) n but negatively with the lowest blood oxygen (r=0.323, P=0.323). Endothelial cell apoptosis rate in the control group and the severe OSAHS group was (2.94±1.02) %, (8.23± 3.01) %, respectively, t=5.97, P<0.001. ET-1 in the control group and the severe OSAHS group was (6.71±5.52), (9.88±4.79) pg/ml, respectively, t=3.018, P=0.141. sICAM-1 in the control group and the severe OSAHS group was (11±8), (20±7) ng/ml, respectively, t=7.58, P=0.014. NO in the control group and the severe OSAHS group was (35±16), (25±5) mol/L, respectively, t=2.01, P=0.067. IL-6 in the control group and the severe OSAHS group was (220±42), (436±178) mol/L, respectively, t=2.77, P<0.05. Conclusion: MIF is closely related to the degree of OSAHS severity, and it may be involved in the development and endothelial injury in OSAHS.