Objective To investigate the relationship between serum albumin, bilirubin and cognitive impairment in patients with mild cognitive impairment (MCI). Methods Serum albumin, total bilirubin, direct bilirubin, indirect bilirubin were analyzed in 89 cases of MCI and 82 cases of cognitively normal control. All of the cases underwent neuropsychological testing by Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). The risk factors of MCI were subject to Logistic regression analysis. Results The serum level of total bilirubin in MCI group were significantly lower than that in controls (P < 0.05). There was no significant difference in albumin between MCI and control group (P > 0.05). The bilirubin level was positively correlated with MMSE scores and MoCA scores (including attention, delayed recall and abstract) (P < 0.05), while no significant correlation between serum albumin level and scores of MMSE and MoCA (P > 0.05) by using Spearman correlation analysis. Logistic regression analysis showed that age, education level, diabetes and serum bilirubin levels were independent risk factors for MCI. Conclusion Our data show that decreased serum level of bilirubin is positively related to cognitive impairment.

Objective To investigate Aβ42 and P-tau levels in cerebrospinal fluid (CSF) of patients with mild cognitive impairment (MCI). Methods CSF of 25 cases of MCI and 14 cases of cognitively normal (CN) were investigated. The CSF levels of Aβ42 and P-tau were detected by ELISA method. Correlation analysis was used to analyze the correlation between P-tau level and MMSE score in MCI. Results The CSF level of Aβ 42 was higher and P-tau was lower in MCI than CN group(P<0.05). P-tau level in MCI was also negatively correlated with MMSE score (P<0.05). Conclusion Aβ42 and P-tau levels in CSF may be valuable biological markers in the diagnosis of MCI. P-tau level in CSF of MCI may be related to the severity of cognitive impairment.