MainDiabetes mellitus has been one of the top ten drivers of the growing global health burden over the past 30 years1,2, propelled by aging populations and increasing environmental and behavioral risks such as air pollution and obesity. In 2021, more than one in ten adults worldwide (537 million people) had diabetes mellitus, and more than three-quarters of them lived in low- and middle-income countries (LMICs). Almost half (45%) of adults aged 20–79 years with diabetes mellitus were unaware of their condition, and about 90% of these individuals lived in LMICs. By 2045, 783 million adults worldwide are expected to have diabetes mellitus, highlighting the growing challenges3. The health burden of diabetes mellitus is unevenly distributed among countries. China is home to the greatest number of individuals aged 20–79 years with diabetes mellitus, followed by India, Pakistan and the United States3. Supplementary Figs. 1–3 show the detailed information on the incidence, the mortality rate and the prevalence of diabetes mellitus in 2021, while Supplementary Fig. 4 shows the trend in diabetes mellitus-related death numbers from 1980 to 2050.The COVID-19 pandemic has increased the burden of diabetes mellitus beyond previous levels. Existing research indicates that diabetes mellitus poses a risk factor for severe complications, hospitalization and death among COVID-19 patients4,5,6,7. Furthermore, COVID-19 also increases the risk of developing type 2 diabetes8,9. For instance, a cohort study revealed that in the postacute phase of illness, individuals with COVID-19 showed an increased risk of incident diabetes (hazard ratio (HR) = 1.40, 95% confidence interval (CI) = 1.36–1.44) in comparison to the control group8.In addition to imposing substantial pain on patients and their relatives and an enormous population-wide health burden, diabetes mellitus also imposes a substantial economic burden. According to the International Diabetes Federation (IDF), diabetes contributed to at least 966 billion (in 2021 US dollars) in global health expenditures (direct costs) in 2021, representing 11.5% of all global health expenditures that year and marking a 316% rise in spending relative to 15 years prior. The IDF has also projected that global diabetes-related health expenditures will rise to 1.05 trillion (in 2021 US dollars) by 2045 (ref. 3). The economic burden of diabetes mellitus is unevenly distributed, with high-income countries facing the highest level of diabetes-related health expenditure as a percentage of gross domestic product (GDP; 1.16%) in 2021, followed by middle-income countries (1.08%) and low-income countries (0.51%)3. Among individual countries, the highest total health expenditure on diabetes in 2021 was incurred by the United States (379.5 billion in 2021 US dollars), followed by China (165.3 billion in 2021 US dollars) and Brazil (42.9 billion in 2021 US dollars), and the highest diabetes-related expenditure per patient was incurred by Switzerland (12,828 in 2021 US dollars), followed by the United States (11,779 in 2021 US dollars) and Norway (11,166 in 2021 US dollars)3. However, data limitations, such as lack of reliable prevalence and mortality estimates, have prevented accurate assessment of the economic burden of diabetes mellitus in LMICs10. Reasonable projections of the economic burden of diabetes mellitus and its distribution across countries are urgently needed to inform the design of evidence-based policies for curbing the disease’s impact.Although several studies on the global or regional economic burden of diabetes mellitus exist, most are based on a summation of the direct and indirect costs of the disease (cost-of-illness approach)10,11,12,13. One study using this approach estimated that the absolute global economic burden of diabetes mellitus will reach 2.2 trillion in constant 2015 US dollars by 2030, accounting for up to 2.2% of annual global GDP12. Another analysis projected that, by 2030, the total economic burden of diabetes in China will reach 460.4 billion (in nominal US dollars), representing up to 1.69% of the nation’s GDP13. However, cost-of-illness studies often overlook economic adjustment mechanisms—for example, that jobs do not remain vacant indefinitely because new workers or physical capital (such as machines or robots) replace the lost labor—that could considerably impact their results. In addition, such approaches are static and disregard the effect of diabetes mellitus on human and physical capital accumulation. To address these shortcomings, the World Health Organization established the Economic Projections for Illness and Cost of treatment (EPIC) model for assessing the economic burden of diseases in 2006. EPIC advanced beyond the cost-of-illness method by incorporating economic adjustments and the effects of disease on human and physical capital accumulation. However, it did not account for the dependency of productivity losses on the distribution of education and experience levels, nor the economic effects of morbidity and treatment costs14. Finally, both EPIC and other previous approaches have not fully accounted for the macroeconomic loss associated with informal caregiving for diabetes mellitus, despite the evidence that this burden is substantial.To fill these gaps, we used a theory-grounded, health-augmented macroeconomic model to estimate the macroeconomic burden of diabetes mellitus in 204 countries from 2020 to 2050 and to find the distribution of that burden across world regions. This approach has previously been used to assess the economic burdens of noncommunicable diseases, road injuries, COVID-19 and risk factors like air pollution and tobacco use15,16,17,18,19,20. To avoid underestimating the cost of care for diabetes mellitus, we also considered the effects of informal care, including changes in labor force participation among family members who must care for diabetic patients. To our knowledge, no previous study has produced a comprehensive global estimate of the economic burden of diabetes mellitus by simulating an economy’s productive capacities at the aggregate level and the impact of diabetes mellitus on these capacities.ResultsGlobal macroeconomic burden of diabetes mellitusWe calculated the macroeconomic burden of diabetes mellitus as the difference in total GDP between 2020 and 2050 in the status quo scenario and a counterfactual scenario in which diabetes mellitus was eliminated. When not considering informal care loss, Table 1 shows the results for the 144 countries with complete data, representing 92.7% global population, and the imputed results for the 60 countries with partial data. The lower and upper boundaries computed in the sensitivity analysis using alternative mortality and morbidity data are included in brackets. To make country estimates comparable, all costs were converted to 2017 international dollars (INT$). The United States faces the largest economic burden of diabetes mellitus at INT$2.5 trillion, followed by India at INT$1.6 trillion and China at INT$1.0 trillion. When considering informal care loss, the largest economic burdens are INT$16.5 trillion in the United States, INT$11.4 trillion in India and INT$11.0 trillion in China (Supplementary Table 8). These results demonstrate that the economic burden of informal care for diabetes mellitus is particularly high. The economic burden of diabetes mellitus as a share of GDP ranges from 0.04% in Nigeria to 0.7% in Niue. Among non-island countries, the Czech Republic has the highest GDP share attributable to diabetes at 0.5%, followed by the United States at 0.4% and Germany at 0.4%. Ireland, Monaco and Bermuda face the three largest per capita economic burdens at INT$18,000, INT$12,000 and INT$8,000, respectively. Globally, the macroeconomic burden of diabetes mellitus is estimated to be INT$10.2 trillion at a discount rate of 2%, INT$8.3 trillion at a discount rate of 3% and INT$15.5 trillion without discounting. We provide country-specific estimates for the additional macroeconomic burden of diabetes mellitus due to COVID-19 infection in Supplementary Table 5. This analysis is entirely separate from the main results presented in Table 1. The additional cases and burden shown in Supplementary Table 5 are not included in the baseline projections. The COVID-19 analysis covers only the impact of infections that were reported between 1 January 2020 and 1 September 2022. The results without informal care and with discounting at 0% are presented in Supplementary Table 6; the results without informal care and with discounting at 3% are presented in Supplementary Table 7 and the results with an average weekly loss of four informal care hours (ranging from 0.285 to 8.3 h) are presented in Supplementary Table 8.Table 1 Total macroeconomic burden, per capita economic burden and economic burden as a percentage of GDP in 2020–2050 attributable to diabetes mellitus by country and World Bank region in 2017 international dollarsFull size tableFigures 1 and 2 depict the macroeconomic burden for all 204 countries as maps without informal care. Figure 1 shows the burden for each country as a percentage of GDP. Figure 2 shows the absolute macroeconomic burden for each country. The deeper a country’s hue on the map, the greater is its economic burden in terms of the specific measure shown. Supplementary Figs. 5 and 6 display the results for 134 countries of the additional diabetes mellitus burden due to the effects of the COVID-19 pandemic.Fig. 1: Macroeconomic burden of diabetes mellitus as a percentage of total GDP in 2020–2050.The map shows the projected macroeconomic burden of diabetes mellitus expressed as a percentage of GDP for 204 countries and territories from 2020 to 2050, based on a health-augmented macroeconomic model. Burden estimates reflect losses in effective labor supply due to mortality and morbidity and the diversion of treatment resources from savings and investment. Countries are shaded according to burden levels, with darker colors indicating higher relative losses. The highest relative burdens (≥0.355% of GDP) are concentrated in small island states and high-income countries such as American Samoa and Australia, whereas much of Africa and South Asia show lower relative burdens (