The changes of serum homocysteine and cystatin Clevels and their effects on cognitive function inpatients with cerebral infarction accompanied by obstructive sleep apnea hypopnea syndrome

  Objective   To investigate the changes of serum homocysteine (Hcy) and cystatin C (CysC) levels and their relationships with cognitive function in patients with cerebral infarction accompanied by obstructive sleep apnea hypopnea syndrome (OSAHS).

  Methods   A total of 52 patients with cerebral infarction accompanied by OSAHS (observation group) and 50 patients with cerebral infarction alone (control group) were selected in the study, and the observation group was divided into mild group (17 cases, accompanied by mild OSAHS) and moderate-severe group (35 cases, accompanied by moderate to severe OSAHS) according to different sleep apnea hypoventilation index (AHI). All patients enrolled in the group underwent polysomnography (PSG), and AHI, mean nocturnal oxygen saturation (MSaO₂), and minimum nocturnal oxygen saturation (LSaO₂) were recorded. Patients′cognitive function was assessed using the Simple Mental State Examination Scale (MMSE) and the Montreal Cognitive Assessment Scale (MoCA). Serum Hcy and CysC levels were measured by enzyme-linked immunosorbent assay (ELISA).

  Results   The serum Hcy and CysC levels of the observation group were higher than those of the control group, and the MMSE score and MoCA score were lower than those of the control group (P < 0.01). The serum Hcy and CysC levels in the moderate to severe group were higher than those in the mild group, and the MMSE score and MoCA score were lower than those in the mild group (P < 0.01). The moderate to severe group had higher AHI, and lower LSaO₂ and MSaO₂ than that in the mild group (P < 0.01). In the observation group, serum Hcy and CysC levels were negatively correlated with MMSE score and MoCA score, and serum Hcy as well as CysC levels were positively correlated with AHI (P < 0.01); serum Hcy and CysC levels were negatively correlated with LSaO₂ and MSaO₂ (P < 0.01).

  Conclusion   The elevated serum levels of Hcy and CysC in patients with cerebral infarction accompanied by OSAHS are related to the impaired cognitive function of the patients. Serum Hcy and CysC levels can reflect the severity of cognitive dysfunction in patients with OSAHS and cerebral infarction to a certain extent.