Potential associated factors of postoperative neurocognitive dysfunction in elderly patients: precursor of BDNF and mature BDNF in serum

Background

With the acceleration of population aging in China, the incidence of postoperative neurocognitive dysfunction (PND) will continue to rise.

Aim

We aim to evaluate whether the precursor of brain-derived neurotrophic factor (proBDNF) and mature brain-derived neurotrophic factor (mBDNF) are associated with PND in elderly patients.

Methods

Eighty-six patients who were scheduled for elective orthopedic surgery under general anesthesia were ultimately enrolled. Referring to previous studies, the patients were divided into the PND group and the non-PND group with the Montreal Cognitive Assessment (MoCA) scale on postoperative day 7. The Spearman test was used to determine the correlations between mBDNF, proBDNF, and PND.

Results

All the participants possessed normal cognitive function before surgery. Compared with those in the nPND group, proBDNF, mBDNF, proBDNF*mBDNF, and MoCA score (all P < 0.001) were lower in the PND group after surgery. The Spearman test showed PND was correlated with postoperative proBDNF (correlation coefficient = -0.391; P = 0.001), mBDNF (correlation coefficient = -0.295; P = 0.006), proBDNF*mBDNF (correlation coefficient = -0.479; P < 0.001), and the ratios of proBDNF (correlation coefficient = -0.388; P < 0.001) and mBDNF (correlation coefficient, -0.375; P < 0.001) from before to after surgery.

Discussion

In this study, PND was significantly associated with postoperative proBDNF and mBDNF; the diagnostic value of postoperative mBDNF combined with proBDNF was superior to that of either index alone.

Conclusions

The PND was significantly associated with postoperative proBDNF and mBDNF.

Trial registration

Chinese Clinical Trial Registry (ChiCTR1800017415, registered date: 07/29/2018), http://www.chictr.org.cn.