Association of diabetes status with cognitive impairment in two Chinese rural communities

Background and purpose: Diabetes may be one of the risk factors of cognitive impairment. In this study, we aimed to investigate the relationship between diabetes status and cognitive impairment among the middle-aged and elderly population (≥40 years) in Chinese rural communities.

Methods: A sample of 3392 participants aged 40 years or older from the China National Stroke Prevention Project (CSPP) between 2015 and 2017 were enrolled in this study. Cognitive function was assessed by the Beijing edition of the Montreal cognitive assessment (MoCA) scale. Cognitive impairment was diagnosed as a MoCA score < 26. Diabetes status was divided into three groups------Normal: fasting plasma glucose (FPG) ≤ 5.5 mmol/L, Prediabetes: 5.6 ≤ FPG ≤ 6.9 mmol/L, Diabetes: FPG ≥ 7.0 mmol/L or with a history of diabetes. Multivariate logistic regression was used to analyze the association between diabetes status and cognitive impairment.

Results: Out of the 3392 enrolled participants, 2023(59.6%) had cognitive impairment, 1586(46.8%) had abnormal fasting plasma glucose including 867(25.6%) prediabetes and 719(21.2%) diabetes. After adjusting for potential risk factors, we found prediabetes (OR: 1.22, 95%CI: 1.03-1.45) and diabetes (OR: 1.28, 95%CI: 1.06-1.55) are all associated with cognitive impairment, especially in the domains of language (prediabetes: OR: 1.14, 95%CI: 1.05-1.25; diabetes: OR:1.13, 95%CI: 1.03-1.24), visuospatial/executive functions (diabetes: OR: 1.50, 95%CI: 1.22-1.84) and attention (diabetes: OR: 1.15, 95%CI: 1.02-1.31).

Conclusions: In this large community-based study, we found diabetes status may be an independent risk factor for cognitive impairment, particularly in domains of language, visuospatial/executive functions, and attention.