Estimating the future burden of type 2 diabetes in Belgium: a modelling study

Objective: To estimate the burden [the incidence, prevalence and mortality] of type 2 diabetes [T2D] in Belgium over ten years [2018-2028] Methods: A microsimulation model [MSM] was developed and implemented as a discrete-event state transition model with two events T2D and death, updated annually. Information from a representative [age, sex, and province] sample of the Belgian adult population [18-80 years] provided by the latest [2018] Belgian Health Interview Survey and complemented with estimates on the prevalence of cardiometabolic risk factors from the latest [2018] Belgian Health Examination Survey was used to recreate a Belgian synthetic population using the R package SimPop after Multiple Imputation by Chained Equations. Starting annually since 2018, individuals in the MSM transition from health to death, with or without developing T2D, were estimated using the Finnish Diabetes Risk Score's concise model with prevalent risk factors [e.g. hypertension, BMI] updated via age-sex-specific transition probabilities. Mortality rates for Belgium were retrieved from the Standardized Procedures for Mortality Analysis database and used to calculate the death probabilities used through the MSM. Results: A total of 3275 [95%UI: 3263, 3287] incident cases T2D per 100,000 inhabitants are expected between 2018 and 2028 in Belgium, with higher rates among older individuals. A modest gender-related gap in T2D incidence, unfavorable to females, is foreseen to increase over the course of 10 years. A total of 393 [387, 400]/100,000 new cases among females compared to 378 [371, 384]/100,000 in males are estimated for 2028. Prevalent T2D is expected to increase by 2028 for both females [+16.4%] and males [+12.6%] from 2018 levels (5419 [5387, 5442]/100,000, and 5627 [5605, 5650]/100,000 respectively). Mortality rates attributed to T2D are expected to remain relatively low (119 [117, 122]/100,0000) and stable up to 2028. A slight decrease in mortality rates among the 65+ years old is expected. Conclusion: The burden of T2D in Belgium is expected to remain high over the next years. Preventive strategies should be strengthened to delay the onset of new T2D cases and decrease the burden.