Widening educational inequalities in type 2 diabetes risk and mediators across successive generations: a prospective cohort study.

Lower educational attainment was associated with higher risk of incident type 2 diabetes in the UK Biobank cohort.

• The analysis included 460,797 participants free of diabetes at baseline, with 19,931 incident T2DM cases over a median follow-up of 16.5 years.
• Primary education or less versus college education: HR 1.92 (95% CI 1.85-1.99) for incident T2DM.
• Fine-Gray proportional subdistribution hazards models were used to account for competing risks.

Lower education was also associated with higher risks of progression from T2DM to cardiovascular disease and of mortality.

• Primary education or less versus college education: HR 1.33 (1.30-1.37) for progression to CVD.
• Primary education or less versus college education: HR 1.53 (1.49-1.57) for mortality.
• Multi-state competing risks models were used to evaluate transitions from T2DM onset to CVD and death.

The overall relative index of inequality (RII) for education and T2DM risk was 2.37.

• Adjusted overall RII was 2.37 (95% CI 2.25-2.50).
• RII was used to quantify the magnitude of educational disparities.

Educational inequalities in T2DM risk widened across successive birth cohorts.

• Participants were stratified into three birth cohorts: pre-1949, 1950-1959, and post-1960.
• Adjusted RII was 2.31 (2.16-2.47) in the pre-1949 cohort.
• Adjusted RII was 2.53 (2.29-2.79) in the 1950-1959 cohort and 2.53 (2.18-2.93) in the post-1960 cohort.
• Disparities in progression to CVD and mortality also widened across birth cohorts, per the abstract.

Socioeconomic, metabolic, and behavioral factors each mediated a substantial proportion of the association between education and T2DM risk.

• Socioeconomic factors accounted for 42.2% (39.2%-45.2%) of the educational inequality.
• Metabolic factors accounted for 42.6% (38.2%-47.3%).
• Behavioral factors accounted for 20.5% (18.9%-22.2%).
• Pathway analysis was used to estimate the mediated proportions.

Education-related inequalities span the whole trajectory from T2DM onset through CVD and death, not only incidence.

• Primary education or less was associated with increased risk at each stage: T2DM incidence, CVD progression, and mortality.
• The study considered these stages jointly rather than separately, which earlier work had largely not done.