A recent study published in the Lancet provided comprehensive estimates of diabetes prevalence and burden worldwide, highlighting the increasing global health threat and informing policy-making efforts.
Study: Global, regional, and national burden of diabetes from 1990 to 2021, with projections of prevalence to 2050: a systematic analysis for the Global Burden of Disease Study 2021. Image Credit: KaterynaNovikova/Shutterstock.com
Background
Diabetes is a chronic disease characterized by high blood glucose levels due to abnormal β-cell biology and insulin action. It affects around 460 million people worldwide and was the eighth leading cause of death and disability in 2019.
Diabetes poses a significant burden on healthcare systems, with global health expenditures reaching over $966 billion in 2021 and estimated to surpass $1054 billion by 2045.
Type 1 and 2 diabetes are the most common forms, with distinct risk factors and management strategies. Low-income and middle-income countries bear a disproportionate disease burden due to socioeconomic challenges.
Accurate data and targeted programs are crucial to address this growing health crisis. The Global Burden of Diseases (GBD) methodological framework is applied to estimate and forecast diabetes prevalence and burden worldwide.
About the study
This study utilized 27,193 data sources and applied the GBD framework to estimate diabetes prevalence and burden from 1990 to 2021. For data collection, the GBD uses systematic reviews, opportunistic searches, and data shared by collaborators and the World Health Organization (WHO).
The study primarily focused on diabetes prevalence and burden, including mortality estimates. Mortality data were used to calculate prevalence and disability-adjusted life-years (DALYs). Age-standardized results were presented for comparison among different populations.
Mortality models were created for type 1, type 2, and total diabetes, and deaths without specified types were predicted through a log-linear regression model. Non-fatal outcomes were estimated using various population-representative sources and individual-level data.
The study incorporated risk factors such as air pollution, smoking, high body mass index (BMI), and low physical activity. Meta-analyses were performed to establish the relationship between risk factors and diabetes, estimating population attributable fractions (PAFs) to quantify the reduction in diabetes burden if risk factors were minimized to theoretical minimum levels.
Forecasting was performed using the sociodemographic index (SDI) for type 1 diabetes and BMI for type 2 diabetes. Such metrics were forecasted through 2050 to estimate future prevalence.
This study followed the guidelines for Accurate and Transparent Health Estimates Reporting (GATHER) statements and complied with the GBD Protocol.
The authors compared GBD estimates with forecasted estimates for 2021 and projected trends through 2050. Parameter uncertainty was considered by randomly drawing 100 samples for each age-sex-location-year-specific parameter. 95% uncertainty intervals (UIs) were calculated from 100 random draws.
Based on epidemiological patterns, results are reported for 204 countries and territories, grouped into seven super-regions and 21 regions.
Study results
The study results are concerning, as they reveal a significant and alarming increase in the prevalence of diabetes worldwide. In 2021, approximately 529 million people were living with diabetes, with a global age-standardized prevalence of 6.1%.
This indicates that more than six out of 100 people worldwide have diabetes. The prevalence uncertainty interval (UI) ranged from 5.8% to 6.5%, reflecting the variability and potential range of estimates.
Age-specific prevalence rates provide crucial insights into the distribution of diabetes across different age groups. The study found that diabetes prevalence exceeded 20% in every age group between 65 and 95 years, with the highest prevalence peaking at 24.4% in the age group of 75 to 79.
For people younger than 20 years, the prevalence was less than 1%. This highlights the strong association between increasing age and higher diabetes prevalence, indicating that aging populations contribute significantly to the overall burden of diabetes.
Furthermore, the study emphasized that type 2 diabetes accounts for 96.0% of all diabetes cases globally. This means that of the estimated 529 million people with diabetes in 2021, approximately 508 million had type 2 diabetes.
High BMI was identified as the primary risk factor for type 2 diabetes, contributing to 52.2% of the global type 2 diabetes DALYs. This suggests that addressing obesity and promoting healthier lifestyles are key strategies to combat the diabetes epidemic and reduce the burden of the disease.
The study projected a worrying trend in the future, with the global age-standardized diabetes prevalence expected to increase by 59.7% by 2050. This means the majority could rise to 9.8%, affecting approximately 1.31 billion people.
Both demographic shifts and trends in obesity drive the increase. Notably, 49.6% of the projected growth is attributed to obesity trends. This emphasizes the urgent need for comprehensive public health interventions to prevent obesity and effectively manage diabetes.
Conclusions
Diabetes is a significant global health threat, with its prevalence and burden increasing worldwide. The WHO has recognized it as a priority and set ambitious targets to reduce its impact.
The present study generated estimates of diabetes prevalence, examining risk factors and projecting future trends. In 2021, there were 529 million people with diabetes, which is expected to double to 1.31 billion by 2050. The study's strength lies in its rigorous methods and collaboration with researchers worldwide.
High BMI was identified as the primary risk factor for type 2 diabetes, which is expected to rise significantly in regions like North Africa, the Middle East, and Oceania. Factors such as changes in food systems and reduced physical activity contribute to this increase.
Addressing obesity, a major driver of diabetes, remains challenging. Early interventions and patient education are crucial, but many countries lack adequate health systems. Efforts to control diabetes are essential, given its impact on health and other diseases.
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