Associations Between Shift Work and Insulin Resistance Markers in >53,000 Workers (Spain)
Summary
This cross-sectional study analyzed health data from 53,053 employed adults in Spain, comparing day workers with night and rotating shift workers. Researchers calculated four validated markers of insulin resistance—TyG, TyG-BMI, METS-IR, and SPISE. Across all indices, shift workers showed significantly higher insulin resistance than day workers, with adjusted odds ratios ranging from 1.49 to 1.89. These associations persisted even after accounting for age, education, physical activity, and dietary patterns. Men consistently showed a higher insulin resistance burden than women.
Why It Matters For Night Shift Workers and Night Owls
Insulin resistance is an early warning sign for diabetes and heart disease. This large-scale study shows that working non-standard schedules independently drives up insulin resistance in both men and women, even when accounting for lifestyle factors. For shift workers, the findings underline that schedule disruption itself—not just diet or exercise—contributes to metabolic strain. That makes workplace health strategies, including regular screening and tailored lifestyle support, essential for reducing long-term diabetes and cardiovascular risk.
Notes
Contemporary European workforce sample.