Socioeconomic and mental health inequalities in global burden of type 2 diabetes: Evidence from the Global Burden of Disease Study 2021

To explore the holistic impact of socioeconomic and mental health inequalities on the global burden of type 2 diabetes. This cross-sectional study used data on the incidence, disability-adjusted life years (DALYs), and mortality of type 2 diabetes as well as DALYs attributable to risk factors during 1990-2021 from the Global Burden of Disease Study 2021. Average annual percent change (AAPC) was applied to assess the temporal trends from 1990 to 2021. Countries were categorised according to levels of sociodemographic index (SDI) and prevalence of depressive disorders or anxiety disorders. In 2021, the highest age-standardised incidence rate (per 100 000 population) for type 2 diabetes was in countries with a higher prevalence of depressive or anxiety disorders (ranging from 466.35 to 517.08), wherein those with higher SDI experienced the fastest increase from 1990 to 2021 (AAPC ranging from 2.51% to 2.61%). The highest age-standardised rates of DALY and mortality (per 100 000 population) for type 2 diabetes in 2021 were in countries with lower SDI, of which countries with a higher prevalence of depressive or anxiety disorders exhibited the greatest burden (ranging from 1714.38 to 2012.12 for DALY; from 48.66 to 51.91 for mortality). The attributable risk factors for DALYs of type 2 diabetes varied across countries with different SDI levels and prevalence of mental disorders. The results suggest that the imbalance of faster socioeconomic development but worse mental health underpins diabetes incidence, while slower socioeconomic development and worse mental health jointly contribute to the disability and mortality burdens of diabetes. It is imperative to promote mental health alongside economic and social development to address the public health challenge of type 2 diabetes.