Highlight
– Over 34 years, approximately 50-65% of Chinese adults with newly diagnosed diabetes (NDD) or impaired glucose tolerance (IGT) experienced stroke.
– Stroke risk was significantly elevated in NDD and IGT groups compared to normal glucose tolerance (NGT), even after adjusting for confounding factors.
– A 6-year lifestyle intervention in the IGT group notably reduced the stroke risk, especially among women.
Study Background and Disease Burden
Stroke remains a leading cause of morbidity and mortality worldwide, with a particularly high burden in China due to demographic and lifestyle factors. Type 2 diabetes mellitus (T2DM) and impaired glucose tolerance (IGT) are well-established risk factors for cardiovascular and cerebrovascular diseases, including stroke. Despite the recognized association between dysglycemia and stroke risk, long-term data quantifying stroke incidence evolution in newly diagnosed diabetes and IGT populations are limited, especially from large-scale, prospective studies in Asian populations. Understanding stroke incidence dynamics over extended periods could elucidate the impact of glycemic status and intervention efficacy on cerebrovascular risk.
Study Design
This cohort study leveraged the Da Qing Diabetes Prevention Study originally initiated in 1986, which systematically identified Chinese adults with newly diagnosed type 2 diabetes (NDD), impaired glucose tolerance (IGT), and normal glucose tolerance (NGT). Participants were followed longitudinally for 34 years to assess stroke outcomes. The IGT subset underwent randomized assignment to either a 6-year lifestyle intervention (focused on diet, physical activity, and weight control) or no intervention (control). Stroke incidence was assessed across the three groups, with hazard ratios (HRs) adjusted for confounders including age, sex, and other cardiovascular risk factors. This design enables direct comparison of long-term stroke risk between glycemic categories and the impact of lifestyle modification.
Key Findings
Cumulative stroke incidence over 34 years was markedly high in individuals with NDD (65.4%) and IGT without intervention (62.8%), compared to a substantially lower rate of 49.8% in the IGT intervention group. Annual stroke incidence was significantly greater in the NDD group compared with the NGT group (24.3 versus 18.5 per 1,000 person-years), even after adjusting for age and sex.
After comprehensive adjustment for additional stroke risk factors, the relative risk of stroke was significantly elevated in all dysglycemic groups relative to the NGT group: NDD (HR 1.80, 95% CI 1.46–2.21, P < 0.001), IGT nonintervention (HR 1.52, 95% CI 1.11–2.07, P = 0.008), and IGT intervention (HR 1.33, 95% CI 1.17–1.63, P = 0.01). Importantly, individuals in the IGT intervention group had a reduced stroke risk compared with those in the NDD group (HR 0.77, 95% CI 0.64–0.94, P = 0.009), indicating a protective effect of lifestyle modification initiated before diabetes onset.
Stratified analyses revealed the stroke risk reduction with lifestyle intervention was especially pronounced in women (HR 0.64, 95% CI 0.47–0.88, P = 0.006), suggesting possible sex-specific benefits or differential adherence.
Expert Commentary
This landmark 34-year follow-up underscores the profound long-term stroke burden associated with dysglycemia in a Chinese cohort. The findings reinforce that newly diagnosed diabetes and impaired glucose tolerance significantly increase stroke risk, corroborating existing evidence linking hyperglycemia with cerebrovascular pathology.
The study’s demonstration of stroke risk attenuation through early lifestyle intervention in the IGT population highlights the critical window for preventative strategies prior to overt diabetes. Lifestyle modification encompassing dietary optimization, physical activity enhancement, and weight management remains a cornerstone of diabetes prevention and now is evidenced to confer sustained cerebrovascular protection.
Gender differences noted call for further exploration of biological, behavioral, and socio-cultural factors mediating intervention responsiveness. Limitations include potential changes in stroke diagnostic criteria and treatment paradigms over the extensive follow-up and possible residual confounding.
Overall, these data bolster guideline recommendations for aggressive risk factor modification in prediabetic and diabetic individuals to mitigate long-term vascular complications.
Conclusion
The Da Qing Diabetes Study’s 34-year follow-up provides compelling evidence that roughly half or more of Chinese adults with newly diagnosed diabetes or impaired glucose tolerance experience stroke. Lifestyle intervention initiated during the IGT stage substantially reduces stroke risk, particularly among women, advocating for intensified early prevention efforts.
These findings emphasize the essential role of comprehensive diabetes management and early, sustained lifestyle intervention in reducing stroke burden. Future research should investigate mechanistic pathways, refine personalized interventions, and address barriers to implementation to enhance cerebrovascular outcomes in at-risk populations.
References
Chen Y, Wang J, Feng X, Qian X, He S, An Q, Yin X, Wang X, An Y, Gong Q, Zhou S, Li H, Zhai X, Chen X, Li G. Stroke Incidence Evolution in People With Newly Diagnosed Diabetes and Impaired Glucose Tolerance: A 34-Year Follow-up of the Da Qing Diabetes Study. Diabetes Care. 2025 Oct 1;48(10):1721-1727. doi: 10.2337/dc24-2675. PMID: 40372382.
