Temporal changes in the burden of type 2 diabetes mellitus across the BRICS, 1990-2021: a comprehensive analysis for the global burden of disease study 2021.

Background: The BRICS (Brazil, Russian, India, China and South Africa) was still in rapid development with great potential to promote the global governance of the type 2 diabetes mellitus (T2DM). The study aimed to offer practical experience and strategies for global T2DM management, particularly for developing countries by evaluating the trends, cross-country inequalities of T2DM burden in the BRICS in the past and further predict their changes to 2035.

Methods: Age-standardized rate of incidence, prevalence, and disability-adjusted life years (DALYs) of T2DM were calculated. Estimated annual percentage change, Joinpoint regression and age-period-cohort model were used to analyze trend, decomposition analysis were used to attribute changes in total DALYs to population aging, population growth, and DALYs change, and Bayesian age-period-cohort model was used to predict.

Results: The cases number and ASR of T2DM incidence, prevalence and DALYs in the BRICS increased from 1990 to 2021, with obvious growth in Russia and South Africa. The highest incident relative risk (RR) in Brazil and China peaked at 55-59 years old with a notable RR in Chinese youths aged 20-24 years old, whereas it peaked at 60-64 years old in Russia, India and South Africa. The higher prevalent RR was after 65 years in the BRICS. The incident and prevalent RRs in the BRICS increased over time except for China where the incident RR decreased since 1995. Individuals born earlier had higher incident and prevalent RRs in Brazil, Russia, India and South Africa while individuals born later had higher incident RRs in China. Males bore a heavier burden of T2DM in India and China while females bore heavier in Brazil, Russia and South Africa. The impacts of population aging, population growth and epidemiological changes in China, Brazil, and Russia were the greatest respectively. The DALYs difference per 100,000 between countries with the lowest and highest SDI was 429.89 (95%CI: 187.62 to 672.17) in 1990, rising to 711.63 (95%CI: 416.73 to 1006.53) in 2021. The health inequality concentration index was - 9.60 (95%CI: -10.00 to -9.20) in 1990 and - 12.91 (95%CI: -13.71 to -12.10) in 2021. Until 2035, the incidence, prevalence and DALYs were projected to increase overall in the BRICS.

Conclusion: Developing comprehensive T2DM guidelines should be a key BRICS cooperation priority, leveraging proven aging population and chronic disease management experiences. Russia, India, and South Africa should prioritize older adults, whereas China and Brazil need to focus on middle-aged and older adults, with China additionally addressing younger-onset T2DM trends. Insulin shortages and severe infectious diseases pose major challenges, particularly in less developed countries, necessitating the expansion of early intervention programs, educational initiatives, and integrated hospital care to enhance T2DM control.