Innovation in diabetes prevention research: The 36-year legacy of China Da Qing diabetes prevention study

Prediabetes, also known as impaired glucose regulation (IGR), is an intermediate stage between normal glycemia and diabetes. It includes people with elevated, but sub-diabetic fasting glucose levels, called impaired fasting glucose (IFG), and postprandial glucose intolerance, called impaired glucose tolerance (IGT). In some diagnostic criteria, individuals with HbA1c 5.7%–6.4% are regarded as prediabetes as well. Around 5%–10% of individuals with prediabetes become diabetic annually, and up to 70% progress to diabetes within their lifetime. As one of the top five chronic diseases in healthcare globally, diabetes incurs an average medical expenditure of nearly one trillion dollars per year. China is the country with the highest number of diabetes cases and diabetes-related death worldwide, urgent action is needed to address diabetes in China. The China Da Qing Diabetes Prevention Study (CDQDPS), a randomized controlled trial started in 1986, demonstrated the efficacy of lifestyle intervention to prevent type 2 diabetes mellitus (T2DM). Along with the US Diabetes Prevention Program (DPP) and the Finnish Diabetes Prevention Study (DPS), the CDQDPS has been regarded as the landmark study for primary prevention of T2DM by lifestyle intervention, but with the longest duration of intervention and follow-up since 1986. Due to long-term follow-up of up to 30 years, the CDQDPS remains the only trial to date that reported the efficacy of lifestyle intervention to reduce the risk of cardiovascular disease (CVD) and death caused by T2DM among individuals with IGT. The global epidemic of T2DM has prompted numerous studies and public health efforts to reduce its development. A crucial challenge is associated with the ununified diagnostic criteria of prediabetes by various international professional organizations, for instance, the American Diabetes Association (ADA) defines IFG as a fasting plasma glucose (FPG) level above 100 mg/dL (5.6 mmol/L), whereas the World Health Organization (WHO) sets the threshold at 110 mg/dL (6.1 mmol/L). Furthermore, the diagnosis of prediabetes based on different measurements: FPG, 2-hour plasma glucose, and HbA1c has different insulin sensitivity, β-cell function, and risk of developing T2DM and incident CVD events. Therefore, it’s important to investigate whether there is a difference in the efficacy of lifestyle intervention to prevent T2DM among individuals with prediabetes defined by different diagnostic criteria, such as isolated IFG (i-IFG), and elevated HbA1c. Additionally, with the advent of the internet as a resource base for research and the need to bridge the know-do gap, further research is required to provide robust evidence on the effectiveness of digital intervention on lifestyle management in preventing T2DM, and it’s necessary to identify barriers and facilitators to implement lifestyle intervention and evaluate the acceptability, adoption, appropriateness, implementation costs, feasibility, fidelity, penetration, and sustainability of interventions. All in all, this review summarizes the background, study design, main results, and contributions of the CDQDPS, and help inform future studies in diabetes prevention and public health efforts to address the epidemic of T2DM.