The number of people living with type 1 diabetes globally is expected to double by 2040, according to the results of a new modeling study.
Funded by JDRF International, results of the study project the number of people with type 1 diabetes worldwide to balloon from 8.4 million, which was the 2021 estimate, up to 13.5-17.4 million by 2040, with the largest relative increases occurring in low- and lower-middle-income countries.
“Given that prevalence of people with T1D is projected to increase in all countries to up to 17.5 million cases in 2040, our results provide a warning for substantial negative implications for societies and healthcare systems,”said study investigator Graham Ogle, MBBS, a pediatric endocrinologist with the University of Sydney, in a statement. “There is an opportunity to save millions of lives in the coming decades by raising the standard of care for T1D and increasing awareness of the signs and symptoms of T1D to enable a 100% rate of diagnosis in all countries. Our model, which will be made available open-source, will make data on the burden of T1D widely accessible and serve as a platform for stakeholders to make improvements in T1D care and outcomes.”
Although type 1 diabetes represents a significant threat to life expectancy, notable gaps in data still exist related to prevalence, incidence, and associated mortality for people with type 1 diabetes. With this in mind, Ogle and a team of colleagues fitted a Markov model with data on type 1 diabetes incidence and associate morality for 201 countries for the year of 2021 to estimate project prevalence in 2040.
Overall, investigators obtained data related to the 1 diabetes incidence form 97 countries and mortality data from 37 countries. For the purpose of analysis, diagnosis rates were estimated using data from an expert survey. Additionally, mortality was modeled using random-first regression of published type 1 diabetes mortality data and life expectancy was calculated using life tables. Investigators pointed out estimates were validated against observed prevalence data for 15 countries.
Investigators found the global prevalence of type 1diabetes in 2021 was approximately 8.4 (95% uncertainty interval [UI], 8.1-8.8) million. Of the 8.4 million with diabetes, 18% were less than 20 years of age, 64% were 20-59 years of age, and 19% were aged 60 years or older. During 2021, investigators estimated there were 500,000 new diagnoses of type 1 diabetes, with a median age at onset of 39 years. Results suggest there were about 500,000 undiagnosed cases in 2021 and, during the same time, investigators estimated about 35,000 undiagnosed patients would die within 12 months of symptom onset.
Investigators highlighted 1.8 million individuals with type 1 diabetes were in low-income and lower-middle-income countries. Comparison of life expectancy revealed the life expectancy of a 10-year-old diagnosed with type 1 diabetes in 2021 ranged from a mean of 13 years in low-income countries to 65 years in high-income countries. By 2040, the results of the modeling study pointed to an increase in prevalence to 13.5-17.4 million, which represents an increase of 60-107% over the 2021 figures, with the greatest relative increases observed among low- and lower-middle-income countries.
“Our findings indicate that the overall footprint of T1D is much larger than previous estimates have indicated, when missing prevalence due to excess mortality is accounted for,” said study investigator Kim Donaghue, MBBS, PhD, head of Diabetes Complications Assessment Services Child and Adolescent Health at the University of Sydney, in the aforementioned statement. “This is particularly true in low- and middle-income countries – for example in sub-Saharan Africa which accounts for 357,000 cases of T1D or 4% of global prevalence but 23% of the lives lost each year—highlighting the urgent need to increase awareness of the signs and symptoms of T1D in lower-middle-income countries."
This study, “Global incidence, prevalence, and mortality of type 1 diabetes in 2021 with projection to 2040: a modelling study,” was published in The Lancet Endocrinology & Diabetes.