Effect of stress on insulin resistance among shift workers based on findings from the Korea National Health and Nutrition Examination Survey (2019, 2021): a retrospective cross-sectional study

Purpose: Insulin resistance is a major driver of metabolic disorders, and understanding factors associated with insulin resistance, particularly among Korean shift workers, is essential for the development of effective preventive strategies. This study aimed to identify factors related to insulin resistance using a complex-sample analysis of national survey data. Methods: In this retrospective cross-sectional study, secondary data were obtained from the 8th Korea National Health and Nutrition Examination Survey conducted in 2019 and 2021. All analyses were performed using a complex sampling design incorporating stratification, clustering, and sampling weights. Insulin resistance was assessed using the homeostatic model assessment for insulin resistance. Complex-sample multivariable logistic regression analyses were conducted to identify factors associated with insulin resistance. Results: The mean age of participants was 44.56 years, and 78.1% were men. Among the participants, 28.5% had insulin resistance. In the multivariable logistic regression analysis, higher body mass index was associated with increased odds of insulin resistance (odds ratio [OR] = 1.31, 95% confidence interval [CI] = 1.16~1.48). The presence of metabolic syndrome was associated with higher odds of insulin resistance compared with its absence (OR = 2.64, 95% CI = 1.31~5.33). Higher perceived stress was also associated with increased odds of insulin resistance (OR = 1.49, 95% CI = 1.04~2.14). Conclusion: Higher body mass index, metabolic syndrome, and elevated stress were associated with insulin resistance in Korean shift workers, highlighting the importance of managing both metabolic and psychological factors to reduce the risk of insulin resistance.