The relationship between systemic biomarkers and postoperative cognitive dysfunction in elderly patients

Objective To determine the relationship between five biomarkers and the progression of postoperative cognitive dysfunction (POCD), so as to provide potential basis and new insights for early diagnosis, prevention and therapy for POCD. Methods A total of 45 elderly patients who underwent elective orthopedics surgery were enrolled into the current prospective study. According to their Mini-Mental State Examination (MMSE) scores at three days after operation, the patients were divided into a POCD group (n=18) and a non-POCD group (NPOCD group, n=27). The levels of five biomarkers [kallikrein-6 (KLK6), superoxide dismutase 1 (SOD1), superoxide dismutase 2 (SOD2), osteopontin (OPN) and contactin-1 (CNTN1)] in plasma were measured at three time points: pre-operation (PREOP), one day after operation (POD1) and three days after operation (POD3). The relationship between biomarkers in plasma and POCD was calculated based on statistical analysis. Results There were 18(40%) patients with the presence of cognitive dysfunction. There was no significant difference in the basal level of KLK6 in plasma between the two groups (P>0.05) at PREOP. The plasma level of KLK6 of the POCD group at POD1 was significant lower (P 0.05). The plasma level of ln (SOD1) at POD3 were significant lower (P 0.05). Conclusions The decrease of KLK6 level in plasma is related to the occurrence and development of POCD in elderly patients. However, the correlation between the expression levels of SOD1, SOD2, OPN and CNTN1 and postoperative cognitive function is still unclear. Key words: Postoperative cognitive dysfunction; Biomarkers; Aged