A study published in The Lancet Diabetes and Endocrinology journal estimates the global incidence of type 1 diabetes in children and adolescents using microsimulation models.
Study: Estimating the total incidence of type 1 diabetes in children and adolescents aged 0–19 years from 1990 to 2050: a global simulation-based analysis. Image Credit: mother_ana / Shutterstock
Background
Type 1 diabetes is characterized by a reduction in insulin production due to the destruction of pancreatic beta cells. The result is an increase in blood glucose levels (hyperglycemia). In the absence of treatment, diabetic ketoacidosis can develop, which is a life-threatening condition.
According to the International Diabetes Foundation (IDF) diabetes atlas, about 149,500 new cases of type 1 diabetes were observed among children and adolescents in 2021 worldwide. According to the Global Burden of Disease study, about 288,263 new cases were identified in 2019. A recent modeling study estimations have indicated 193,516 incident cases in 2021.
With the significant variations in reported incidence, whether country-level differences in healthcare systems and underdiagnosis influence these reported incidence rates remain uncertain.
In the current study, the scientists have estimated both totals and diagnosed incidences of type 1 diabetes among children and adolescents using a global microsimulation model.
Study design
The scientists developed a global microsimulation model of type 1 diabetes to simulate the natural history and diagnosis of the disease for children and adolescents from 200 countries and regions.
A demographically representative population of children and adolescents in each country was used to simulate the incidence, natural history, and diagnosis of type 1 diabetes. Also included in the model were factors related to the healthcare system that might affect estimations.
Also, the model was calibrated to estimate the incidence, autoantibody profiles, and proportion of diabetic ketoacidosis cases in each country from 1990 to 2050. The autoantibody profile acts as an immunologic biomarker to identify children at the highest risk of developing type 1 diabetes.
Important observations
The microsimulation model developed in the study estimated a total of 355,900 new cases of type 1 diabetes among children and adolescents in 2021 globally. About 56% of these cases were diagnosed.
Considering the current trends, the model predicted that the total incident cases would increase to 476,700 per year in 2050. About 72% of these cases would be diagnosed.
There was a significant variation in underdiagnosis between countries. For example, while more than 95% of new cases were predicted to be diagnosed in Australia and New Zealand, western and northern Europe, and North America, only 35% of new cases were expected to be diagnosed in west Africa, south and southeast Asia, and Melanesia.
A considerable variation in incidence rate was observed between continents. According to the model predictions, Europe would experience a faster induction in incidence rate than other continents.
Because of population growth and higher incidence rate, Africa is predicted to have the highest number of new cases worldwide. By 2050, Africa and Asia are projected to account for 51% and 28% of global new cases per year, respectively.
Considering income groups, low-income, lower-middle-income, upper-middle-income, and high-income countries are expected to account for 25%, 44%, 17%, and 14% of global new cases, respectively.
Regarding the proportion of children and adolescents with diabetes ketoacidosis at diagnosis, the percentage of cases is predicted to decrease from 80% in 1990 to 40% in 2050 in low-income countries. In high-income countries, the same rate is expected to fall from 35% in 1990 to 24% in 2050. Africa and Asia are predicted to have the highest percentage of cases of diabetic ketoacidosis.
According to the model estimations, about 90% of diagnosed cases were positive for at least one islet cell autoantibody in 2021. However, the positivity rate was comparatively lower in Africa and Asia, highlighting the impact of genetic and environmental factors on autoantibody positivity.
Study significance
The study estimations indicate that the current global incidence rate of type 1 diabetes among children and adolescents is higher than previous estimates. With a significant variation in diagnosis rate between countries, only 50% of global new cases are diagnosed.
As suggested by the scientists, healthcare policymakers should plan for adequate testing facilities for timely diagnosis and treatment of type 1 diabetes.