Predicting individual responses to lithium with oxidative stress markers in drug-free bipolar disorder

Abstract

Objectives: This is the first study to investigate the oxidative stress (OxS) levels in drug-free bipolar disorder (BD) patients and their association with lithium response.

Methods: A total of 61 drug-free BD patients and 49 controls were included. Patients treated with lithium were followed-up for 6 weeks. The levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and malondialdehyde (MDA) were measured at baseline and at the end of the sixth week.

Results: Compared to controls, the SOD levels were lower, whereas the MDA were higher in the BD-depression (BD-D) group (both P < 0.001). GSH-Px levels were higher in both the BD-D and the BD-mania (BD-M) group (both P < 0.001). Both GSH-Px and MDA levels in the BD (P = 0.009, P < 0.001) and the BD-D subgroup (P = 0.006, P = 0.001) decreased significantly after the 6-week treatment with lithium. Interestingly, both GSH-Px and MDA levels decreased in responders (P = 0.03, P = 0.002) but not in the non-responders of BD-D (both p > 0.05). Moreover, the reduction in the MDA levels were associated with lithium response (B = 1.47, Wald statistic = 5.94, P = 0.015, odds ratio = 4.35, 95% confidence interval 1.33-14.20).

Conclusions: Our study demonstrates an imbalance of OxS in drug-free BD, especially BD-D. Lithium reduces the GSH-Px and MDA levels in BD patients. The reduction in MDA levels may predict individual responsiveness to lithium.

Keywords:

• Oxidative stress markers
• bipolar disorder
• lithium
• response
• drug-free

Acknowledgements

We would like to thank Dr. Yong Wang and Chengqing Yang for all of their hard work and significant contribution towards this study. We also thank the participants who were recruited in present study.

Statement of interest

The authors declare no competing interests.

Data available statement

The datasets of the current study are available from the corresponding author on reasonable request.

Author's contributions

Q.L., Y.H. and Z.L. wrote the paper. M.Z., R.G., X.C., C.B. and Y.W. assessed and followed up the participants. X.H. was the main study coordinator. C.Z. and Y.H. cleaned and analysed the data. Z.L. and Z.Y. were responsible for study design and quality control.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China [81671326, 81401127]; National Basic Research Programme of China [2016YFC0906402]; The Fundamental Research Funds for the Central Universities of Shanghai Jiao Tong University [16JXRZ06]; The Shanghai Science and Technology Commission Foundation [17411970000]; Shanghai Mental Health Centre Programme [2017-YJ-01, 2014-YJ-04, 2015-YJGJ-03]; Shanghai Jiao Tong University Medicine-Engineering Foundation [YG2016MS, YG2015MS52]; Shanghai Natural Science Foundation [15ZR1412900]; Shanghai Municipal Commission of Health and Family Planning Found [20134Y044]. All funding for this study had no further role in study design, data analysis, or in the decision to submit the paper for publication.