Social disparities in early onset type 2 diabetes in the workforce: a vertical-horizontal approach

Abstract Background Early onset type 2 diabetes (T2D) is a growing public health issue linked to severe complications and reduced quality of life, affecting the workforce. Socioeconomic (SES) factors, both vertical (income, education, occupation) and horizontal (e.g., occupational sectors), are key determinants of health. While vertical SES disparities in T2D have been widely studied, no research has integrated both vertical and horizontal perspectives to identify at-risk groups. This study addresses that gap by examining vulnerable populations within the workforce. Methods We analyzed 2019 data from AOKN, the largest health insurance provider in Lower Saxony, Germany. Logistic regression assessed education and income disparities in early onset T2D across nine occupational sectors. Age and gender-adjusted predicted probabilities were estimated to compare rates across education levels, income brackets, and occupational groups. Regression tree analysis explored intersectionality between vertical and horizontal factors to pinpoint vulnerable groups. Results Both vertical and horizontal disparities in early onset T2D were found among employed individuals. Education and income inequalities were evident across occupational sectors, while early onset T2D prevalence varied significantly within the same education and income levels across different sectors. Occupational sector affiliation was the primary determinant of T2D vulnerability, followed by education. Workers with lower education in sectors such as ‘Transport, Logistics, Protection and Security’ and ‘Health, Social Work, Teaching and Education’ were particularly at risk. Conclusions The occupational context is a critical determinant of health, regardless of SES hierarchy. To effectively identify vulnerable groups, both vertical and horizontal dimensions of inequality must be considered in public health research. Future studies should adopt this dual approach and apply it to other populations and health conditions. Key messages • Occupational contexts significantly influence early onset T2D risk, with workers in the health and transport sectors being particularly vulnerable, especially those with lower education. • Combining vertical (income, education) and horizontal (occupational sector) social factors is essential for examining disparities and identifying vulnerable groups in public health research.