Socioeconomic and migration-related disparities in prevalent young-onset type 2 diabetes: data from the German National Cohort (NAKO)

OBJECTIVES: Global prevalence of young-onset type 2 diabetes (YOT2D)- diagnosis age 20 - 45-is rising. While clinical drivers such as obesity are known, the role of socio-cultural factors in European high-income settings remain underexplored. We investigated the associations of socioeconomic position (SEP), migration background, and social networks with prevalent YOT2D within the German National Cohort (NAKO). STUDY DESIGN: Matched case-control study within the NAKO baseline cohort (recruitment period 2014 - 2019). METHODS: We matched 808 YOT2D cases in 1:5 ratio to 4035 controls by sex, age, and study center. We applied conditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for parental diabetes, lifestyle factors, and body mass index (BMI). We also performed stratified analyses by BMI (cut-off 25 kg/m) to examine if associations varied across adiposity levels. RESULTS: In multivariable-adjusted analyses, low education (OR 2·13, 95%CI 1·44 - 3·15) and poverty-risk household income (OR 2·13, 95%CI 1·54 - 2·94) were associated with two-times higher odds of YOT2D compared to high-status counterparts. First-generation migrants showed higher odds of YOT2D (OR 1·61, 95%CI 1·27 - 2·04) relative to non-migrants. Notably, the association between low education and YOT2D was evident only among individuals with BMI ≥25 kg/m (OR 1·76, 95%CI 1·46 - 2·11) but not among those with BMI <25 kg/m (OR 0·94, 95%CI 0·70 - 1·27). CONCLUSIONS: Our results highlight that YOT2D prevalence is associated with socioeconomic disadvantage and migration history. These findings emphasize the urgent need for targeted strategies that address health inequities faced by younger, socioeconomically vulnerable populations.