Socioeconomic position and type 2 diabetes: The mediating role of physical work environment - the Maastricht study

Low socioeconomic position (SEP) is a risk factor for type 2 diabetes (T2D) creating socioeconomic health disparities. These inequalities might arise from differences in environmental conditions across SEP groups. People with a lower SEP might have more adverse work conditions compromising their health. We explore the mediating role of the physical work environment in socioeconomic inequalities in T2D. Cross-sectional and longitudinal data from 9009 participants of The Maastricht Study who reside in Southern Netherlands were used. SEP indicators (education, occupation, income) and physical work environment (e.g., noisy work environment) were self-reported at baseline which took place between September 2010 and October 2020. T2D defined based on an oral glucose tolerance test at baseline and self-reported in annual surveys up to 12.8 years (median = 8.2; IQR = 4.9). Occupations were matched with a job exposure matrix to indicate physical and environmental demands. Multiple linear, multinomial logistic regression, and counterfactual mediation analyses were conducted. 21.8% of the study sample had prevalent T2D, and 3.7% reported incident T2D. Lower SEP (e.g., education: HR = 2.04, 95%CI: 1.52,2.75) and adverse physical work environments (e.g., noisy work environment: HR = 1.25, 95%CI: 1.08,1.45) were associated with incident T2D. Education had the most robust associations with T2D. The relationship between SEP and T2D was explained up to 18.2% by self-reported physical work environment and up to 24.4% by physical and environmental demands. Socioeconomic inequalities in T2D persist and can be partially attributed to negative physical work environments. Improving the physical work environment of those with low SEP can help decrease inequalities.