Association between triglyceride glucose index (TyG) and psychotic symptoms in patients with first-episode drug-naïve major depressive disorder

Junjun Liu; Yangchun Wang; Wei Mu; Yang Liu; Ruixiang Tong; Zhaomin Lu; Hsinsung Yuan; Fengnan Jia; Xiaobin Zhang; Zhe Li; Wanqiu Yang; Xiangdong Du; Xiangyang Zhang

doi:10.3389/fpsyt.2024.1342933

Association between triglyceride glucose index (TyG) and psychotic symptoms in patients with first-episode drug-naïve major depressive disorder

Front Psychiatry. 2024 Feb 23:15:1342933. doi: 10.3389/fpsyt.2024.1342933. eCollection 2024.

Authors

Junjun Liu^#^{1

2

3}, Yangchun Wang^#², Wei Mu^#⁴, Yang Liu², Ruixiang Tong², Zhaomin Lu², Hsinsung Yuan², Fengnan Jia³, Xiaobin Zhang³, Zhe Li³, Wanqiu Yang⁴, Xiangdong Du^{1

3}, Xiangyang Zhang⁵

Affiliations

¹ Soochow University, Suzhou, China.
² Nanjing Meishan Hospital, Nanjing, China.
³ Suzhou Guangji Hospital, The Affiliated Guangji Hospital of Soochow University, Suzhou, China.
⁴ School of Ethnology and Sociology, Yunnan University, Kunming, China.
⁵ CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.

^# Contributed equally.

Abstract

Objective: Major depressive disorder (MDD) sufferers frequently have psychotic symptoms, yet the underlying triggers remain elusive. Prior research suggests a link between insulin resistance (IR) and increased occurrence of psychotic symptoms. Hence, this study sought to investigate the potential association between psychotic symptoms in Chinese patients experiencing their first-episode drug-naïve (FEDN) MDD and the triglyceride glucose (TyG) index, an alternative measure of insulin resistance (IR).

Methods: Between September 2016 and December 2018, 1,718 FEDN MDD patients with an average age of 34.9 ± 12.4 years were recruited for this cross-sectional study at the First Hospital of Shanxi Medical University in China. The study collected clinical and demographic data and included assessments of anxiety, depression, and psychotic symptoms using the 14-item Hamilton Anxiety Rating Scale (HAMA), the 17-item Hamilton Depression Rating Scale (HAMD-17), and the positive subscales of the Positive and Negative Syndrome Scale (PANSS), respectively. Measurements of metabolic parameters, fasting blood glucose (FBG), and thyroid hormones were also gathered. To assess the correlation between the TyG index and the likelihood of psychotic symptoms, the study used multivariable binary logistic regression analysis. Additionally, two-segmented linear regression models were employed to investigate possible threshold effects in case non-linearity relationships were identified.

Results: Among the patients, 9.95% (171 out of 1,718) exhibited psychotic symptoms. Multivariable logistic regression analysis showed a positive correlation between the TyG index and the likelihood of psychotic symptoms (OR = 2.12, 95% CI: 1.21-3.74, P = 0.01) after adjusting for confounding variables. Moreover, smoothed plots revealed a nonlinear relationship with the TyG index, revealing an inflection point at 8.42. Interestingly, no significant link was observed to the left of the inflection point (OR = 0.50, 95% CI: 0.04-6.64, P = 0.60), whereas beyond this point, a positive correlation emerged between the TyG index and psychotic symptoms (OR = 2.42, 95% CI: 1.31-4.48, P = 0.01). Particularly, a considerable 142% rise in the probability of experiencing psychotic symptoms was found with each incremental elevation in the TyG index.

Conclusions: Understanding the non-linear link between the TyG index and the risk of psychotic symptoms in Chinese patients with FEDN MDD highlights the potential for targeted therapeutic approaches. By acknowledging the threshold effect observed, there is an opportunity to mitigate risk factors associated with IR-related psychiatric comorbidities through tailored interventions. These preliminary results stress the need for further longitudinal research to solidify these insights and contribute to more effective therapeutic strategies.

Keywords: insulin resistance; major depressive disorder; psychotic symptoms; triglyceride glucose index; type 2 diabetes mellitus.

Grants and funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. This work was supported by the Suzhou Gusu Health Talents Scientific Research Project (Nos. GSWS2021053, GSWS2019070), Key Diagnosis and treatment Program of Suzhou (LCZX202016), the Suzhou clinical Medical Center for mood disorders (Szlcyxzx202109), China Rural Social Survey (Yunnan) (CRSS), the Medical Science and Technology Development Foundation, Nanjing Department of Health (Nos. YKK21216, YKK20184, YKK22264). The funding sources of this study had no role in study design, data collection and analysis, decision to publish, or preparation of the article.