Abstract
OBJECTIVE: An alternative metric for evaluating insulin resistance (IR) is the triglyceride glucose-body mass index (TyG-BMI). However, it is yet unclear how TyG-BMI and suicide attempts (SA) are related. The objective of this research was to explore the correlation between the TyG-BMI index and SA in individuals with untreated first-episode (UFE) major depressive disorder (MDD) in Shanxi Province. METHODS: This cross-sectional study was conducted from September 2016 to December 2018 in the psychiatric outpatient clinic of Taiyuan General Hospital and included 1718 patients with UFE MDD, with a mean age of 34.9 ± 12.4 years. The relationship between TyG-BMI and SA was assessed using logistic regression modeling. We investigated threshold effects using a two-piecewise linear regression model. RESULTS: Taking into consideration the potential influence of confounding variables, a comprehensive multivariate logistic regression analysis was conducted, which demonstrated the absence of a statistically significant association between the TyG-BMI index and the occurrence of SA, as evidenced by P-values that were all greater than 0.05. On the other hand, the visual analysis of the smoothed plots revealed a U-shaped relationship between the TyG-BMI index and the incidence of SA, with a notable inflection occurring at a TyG-BMI value of around 210. It was observed that the effect sizes flanking the inflection point, accompanied by their 95% confidence intervals, were 0.985 (95% CI: 0.972 to 0.999, P = 0.031) and 1.012 (95% CI: 1.003 to 1.047, P = 0.005), respectively. CONCLUSIONS: In UFE MDD patients, a U-shaped link was observed between TyG-BMI and SA, with the minimal SA incidence noted at a TyG-BMI level of 210, signifying that an augmented risk for SA might be connected to both diminished and augmented TyG-BMI levels.