Title: Impact of diabetes on cognitive function in middle-aged and older adults: A longitudinal study
Abstract:Objective :This study investigated diabetes' impact on cognitive dysfunction in middle-aged/older adults (≥45 years) and explored underlying mechanisms, including the mediating role of Activities of Daily Living (ADL) and moderating effects of sleep, depression, and exercise.Methods:Using unbalanced panel data from the China Health and Retirement Longitudinal Study (CHARLS, Waves 1–5; N = 16,856), linear mixed-effects models and Cox regression assessed diabetes-related cognitive decline. Mediation/moderation analyses tested mechanisms, and subgroup analyses examined heterogeneity by age, diabetes status, obesity, and residence.Results:Diabetes demonstrated a significant negative association with cognitive function (β = −0.140, p < 0.01). ADL mediated 10.87 % of this adverse effect. Moderator analyses revealed excessive sleep (>9 h) exacerbated diabetes-related cognitive decline more substantially than insufficient sleep (<6 h) (β = −0.517 vs. -0.242, p < 0.01), and depressive symptoms amplified cognitive detriment (β = −0.020, p < 0.01). Conversely, regular physical exercise (β = 0.171, p < 0.1) and intergenerational co-residence (β = 0.207, p < 0.1) significantly attenuated diabetes-induced cognitive impairment. Subgroup analyses identified heightened vulnerability among individuals with diabetes (β = −0.222, p < 0.05), younger seniors (60–79 years), non-abdominally obese participants, and those living in spacious accommodations (per capita >40 m2).Conclusions:Diabetes adversely impacts cognitive function partially through ADL impairment. However, maintaining regular sleep patterns, emotional well-being, and consistent physical exercise may mitigate this association. Intergenerational co-residence also showed protective potential. Implementing targeted lifestyle interventions addressing these modifiable factors-particularly in identified high-risk subgroups like diabetics and younger seniors-could help ameliorate cognitive decline in middle-aged and older adults with diabetes.
Keywords:Diabetes;Cognitive function;Middle-aged and older adults;Mechanisms of action
DOI:https://doi.org/10.1016/j.jad.2025.120754
