Modeling diabetes progression with risk factors: A case study in China

Approximately 537 million adults worldwide have diabetes, more than 90 % of which is type 2 diabetes mellitus (T2DM). China has the largest number of people living with diabetes. Understanding the epidemiological mechanism can guide diabetes surveillance and control.

Utilizing the most recent Global Burden of Disease 2021 (GBD2021) data on T2DM and risk factor exposure values, we developed a modelling framework that employs systems of difference equations to project the future burden of diabetes among the Chinese population. The model characterized the diabetes progression process from no diabetes, undiagnosed diabetes, and diagnosed diabetes with and without complications, in which genetic and lifestyle factors modulate the rate of development at these stages. We focused on the long-term dynamics of diabetes progression with the impacts of influence factors. We then fit the model to the longitudinal numbers of T2DM patients by Markov chain Monte Carlo (MCMC) algorithm.

The model with the influencing factors fitted an R² of 98 % for the T2DM cases in China during the period 1990-2021. The incidence rate would keep increasing from 299.93/100,000 in 2022 to 421.58/100,000 in 2050 and 500.16/100,000 in 2080. The prevalence rates in 2040, 2060, and 2080 could be 14.62 %, 23.57 % and 34.83 %, respectively. The number of new cases was the most sensitive to high body mass index (BMI), followed by smoking and low physical activity. A 50 % reduction in single risk factor exposure would reduce new cases in 2022-2080 by 4.24 %, 2.52 %, and 1.12 %, respectively.

This study provided a modelling framework to explore the mechanism of T2DM development, which allows to quantify the impacts of risk factors on T2DM progression. The results highlight the high burden of T2DM in China and emphasized the importance of lifestyle interventions.