CYSTATIN-C, Β2-MACROGLOBULIN, AND MACROPHAGE MIGRATION INHIBITORY FACTOR IN OBSTRUCTIVE SLEEP APNOEA HYPOPNEA SYNDROME

Jia Zhou, Zhicong Liu, Lingyan Zhou, Haiyun He^* 

Department of Pulmonary and Critical Care Medicine, pccm, Huzhou Cent Hospital, Affiliated Cent Hospital Huzhou University, 198 Hongqi Rd, Huzhou, Zhejiang, 313000, China

Objective: To investigate the relationships between cystatin C (Cys-C), β₂-macroglobulin (β₂-MG), and macrophage migration inhibitory factor (MIF) levels in patients with obstructive sleep apnoea hypopnea syndrome (OSAHS). 

Methods: Overall, 215 patients with OSAHS admitted to our hospital from January 2019 to January 2020 were selected as the observation group. Based on the apnoea hypopnea index (AHI) and lowest oxygen saturation (LSaO₂) scores, they were divided into three groups: mild (n=85) moderate (n=72), severe (n=58). According to the draft OSAHS guidelines, they were also divided into a good prognosis group (n=120) and a poor prognosis group (n=95). At the same time, 40 healthy people attending the physical examination centre of our hospital were selected as the control group (n=40). The serum levels of Cys-C, β₂-MG, and MIF were detected by the double-antibody sandwich method. The correlations of serum Cys-C, β₂-MG, and MIF with OSAHS were analysed. 

Results: The Cys-C and MIF levels of the observation group were significantly higher than those of the control group and increased with the severity of OSAHS (p<0.05). The level of β₂-MG in the severe group was significantly higher than that of the control, mild, and moderate groups (p<0.05). AHI increased with the severity of OSAHS, whereas LSaO₂ and whole-night mean saturation (MSaO₂) decreased with the severity of OSAHS, and these differences were statistically significant (p<0.05). LSaO₂ was negatively correlated with Cys-C, β₂-MG, and MIF (r=0.623, 0.585, 0.632, respectively; p<0.01). LSaO₂ was negatively correlated with Cys-C, β₂-MG, and MIF (r=–0.521, –0.681, and –0.594, respectively; p<0.05 or <0.01). MSaO₂ was negatively correlated with Cys-C, β₂-MG, and MIF (r=–0.587, –0.538, and –0.682, respectively; p<0.05 or <0.01). The serum Cys-C, β₂-MG, and MIF levels in the poor prognosis group were significantly higher than those in the good prognosis group (p<0.01). 

Conclusion: The level of serum MIF in OSAHS patients was increased, which could indirectly reflect the degree of insulin resistance and indicate disordered glucose metabolism. Compared with serum β₂-MG, serum Cys-C could comprehensively reflect renal injury in OSAHS patients, playing an important role in the diagnosis of early renal injury. In addition, serum Cys-C, β₂-MG, and MIF levels were related to the severity of OSAHS, which provide a powerful test to evaluate the disease status.