New data supports an association of depression with triglyceride glucose index among adults

Major depressive disorder (MDD) is a common mental illness that has impacted human health and garnered widespread global attention. According to the WHO, depression will become the world’s leading health problem by 2030. However, existing antidepressants were developed based on the monoamine neurotransmitter hypothesis, and are not always clinically effective, showing a clinical response rate of <70%. Therefore, it is urgent to discover the pathogenesis of depression and possible therapeutic targets.

The TyG index can be used for IR assessment. The index is based on fasting triglyceride (TG) levels and glucose rather than glucose and insulin. TyG is suggested to be more convenient for clinical use and is an inexpensive and reliable alternative test for IR estimation. Previous studies have indicated interactions between insulin resistance and depression.

Against the above background, Peiyuan Lv, Department of Neurology, Hebei Medical University, Shijiazhuang, China, and colleagues investigated the association between the TyG index and depression to evaluate the presence of insulin resistance in depression. They also determined whether there is a difference between depressed patients and healthy controls.

The study included 198 middle-aged and elderly patients who were admitted to the Hebei General Hospital between 2021 and 2022, together with 189 healthy adults as controls. Depression diagnosis was done according to ICD-10 diagnostic criteria for depression. Insulin resistance was assessed by the TyG index.

The study led to the following findings:

• Compared with the control group, patients suffering from depression had a higher TyG index.
• There were significant differences in the sex ratio, body mass index, family history, total cholesterol, high-density lipoprotein, fasting blood glucose, and low-density lipoprotein levels between the two groups.
• After excluding other confounding factors, the TyG index was found to be independently associated with depression, with an OR of 2.75.

"Our results suggest that there was a correlation between the TyG index and depression in elderly adults," the researchers wrote. "The TyG index was revealed to be higher in elderly patients with major depressive disorder than in the healthy controls."

The limitation of the study was its cross-sectional nature due to which the causal relationship between IR and depression could not be determined and changes in IR following antidepressant treatment were not analyzed and researchers suggest that it should be investigated in future studies.

Reference:

Zhang, Shipan MDa,b,c; Hou, Zhaowei MDd; Fei, Di MDb; Zhang, Xueru MDb; Gao, Chenyang MDb; Liu, Jing MDb; Jin, Man MDa,b,c; Zhai, Xiaoyan MDa,b; Zhou, Yaqing MD, PhDe; Ni, Aihua MDb; Lv, Peiyuan MD, PhDa,b,c,*. Associations between triglyceride glucose index and depression in middle-aged and elderly adults: A cross-sectional study. Medicine 102(43):p e35530, October 27, 2023. | DOI: 10.1097/MD.0000000000035530