Metabolic bridge between sleep disturbances and depression: mediating effects of insulin resistance and clinical implications.

Abstract

Background: This study's objective was to investigate the mediating role of insulin resistance (IR) in the association between sleep disturbances and depression and reveal its underlying biological mechanisms and clinical implications.

Methods: The present study's sample population was derived from data collected during the period of 2005 to 2014 as part of the National Health and Nutrition Examination Survey. The total sample size comprised 20,510 adults. The utilization of multidimensional sleep assessment (sleep duration, trouble sleeping, and sleep disorders), the PHQ-9 depression scale, and clinically validated IR indicators (METS-IR, TyG, and TyG-BMI) was undertaken to parse associations between variables and quantify mediating effects. This was accomplished by constructing multivariable adjusted modeling, restricted cubic spline modeling, causal-mediation analytic frameworks, and using multiple imputation techniques to address missing data.

Results: The results of the study indicated a significant association between sleep disturbances and depression. Sleep disturbances were defined as trouble sleeping, sleep disorders, and poor sleep patterns. Additionally, there was a significant positive association between IR indicators and depression. Following the implementation of confounder adjustment, a unit increase in METS-IR was associated with a 2% increase in the prevalence of depression (OR = 1.02, 95% CI: 1.01-1.02). The ORs for TyG and TyG-BMI were 1.36 (95% CI: 1.26-1.45) and 1.01 (95% CI: 1.01-1.01), respectively. The relationship between sleep disturbances and depression was partially mediated by IR, with mediation ratios ranging from 1.94% to 7.34%. The most substantial mediating effect (7.34%) was observed for TyG-BMI. Furthermore, it was observed that individuals with poorer sleep quality exhibited an elevated prevalence of IR and depression (P for trend < 0.001). The mediating effect of IR indicators remained significant after multiple imputations were used to address missing variables.

Conclusion: IR constitutes a significant biological mechanism that links sleep disturbances to depression. The enhancement of sleep quality and the regulation of IR may be pivotal in preventing and managing depression. Future studies should further validate the causality and mechanism of this relationship and explore effective interventions.

Trial registration: Not applicable.