More than half a billion people are living with diabetes worldwide, affecting men, women, and children of all ages in every country, and that number is projected to more than double to 1.3 billion people in the next 30 years, with every country seeing an increase, as published today in The Lancet.

The latest and most comprehensive calculations show the current global prevalence rate is 6.1%, making diabetes one of the top 10 leading causes of death and disability. At the super-region level, the highest rate is 9.3% in North Africa and the Middle East, and that number is projected to jump to 16.8% by 2050. The rate in Latin America and the Caribbean is projected to increase to 11.3%.

Diabetes was especially evident in people 65 and older in every country and recorded a prevalence rate of more than 20% for that demographic worldwide. The highest rate was 24.4% for those between ages 75 and 79. Examining the data by super-region, North Africa and the Middle East had the highest rate at 39.4% in this age group, while Central Europe, Eastern Europe, and Central Asia had the lowest rate at 19.8%.

Almost all global cases (96%) are type 2 diabetes (T2D); all 16 risk factors studied were associated with T2D. High body mass index (BMI) was the primary risk for T2D—accounting for 52.2% of T2D disability and mortality—followed by dietary risks, environmental/occupational risks, tobacco use, low physical activity, and alcohol use.

"The rapid rate at which diabetes is growing is not only alarming but also challenging for every health system in the world, especially given how the disease also increases the risk for ischemic heart disease and stroke," said Dr. Liane Ong, lead author and Lead Research Scientist at the Institute for Health Metrics and Evaluation (IHME) at the University of Washington's School of Medicine. "While the general public might believe that T2D is simply associated with obesity, lack of exercise, and a poor diet, preventing and controlling diabetes is quite complex due to a number of factors. That includes someone's genetics, as well as logistical, social, and financial barriers within a country's structural system, especially in low- and middle-income countries."

"Some people might be quick to focus on one or a few risk factors, but that approach doesn't take into account the conditions in which people are born and live that create disparities worldwide," said Lauryn Stafford, second author and Post-Bachelor Fellow at IHME. "Those inequities ultimately impact people's access to screening and treatment and the availability of health services. That's precisely why we need a more complete picture of how diabetes has been impacting populations at a granular level."

Using the Global Burden of Disease (GBD) 2021 study, researchers examined the prevalence, morbidity, and mortality of diabetes for 204 countries and territories by age and sex between 1990 and 2021 and forecasted diabetes prevalence to 2050. They also provided estimates of type 1 diabetes (T1D) and type 2 diabetes (T2D) and quantified the proportion of T2D burden attributable to 16 risk factors. The study team included researchers from IHME and GBD 2021 collaborators from around the world.