Public Health

Area of Science:

• Neuroscience
• Endocrinology
• Public Health

Background:

• Diabetes mellitus is a recognized risk factor for dementia.
• The impact of diabetes on cognition and brain structure in non-demented individuals, especially in rural India, is understudied.
• This research investigates the relationship between diabetes, cognitive abilities, and brain MRI findings in middle-aged and older adults in rural India.

Purpose of the Study:

• To examine the association between diabetes and cognitive performance in a rural Indian population.
• To investigate the link between diabetes and brain structure using MRI.
• To assess the influence of diabetes on cognitive functions and brain morphology in individuals without dementia.

Main Methods:

• Cross-sectional study of 3,983 participants (≥45 years) from the CBR-SANSCOG cohort in rural South India.
• Diabetes diagnosed via clinical history or HbA1c ≥6.5%. Cognitive function assessed using the COGNITO battery.
• Brain MRI (n=1,336) analyzed with VBM; multivariate regression adjusted for confounders.

Main Results:

• Individuals with diabetes showed poorer performance in attention tasks (visual attention, reaction time) compared to non-diabetics (p<0.05).
• Higher HbA1c levels correlated with worse attentional task performance.
• MRI revealed reduced grey matter volume in the bilateral cerebellum and right putamen in individuals with diabetes (p<0.05).

Conclusions:

• Diabetes is linked to attention deficits and grey matter loss in the cerebellum and putamen, preceding dementia onset in rural Indians.
• Worsening glycemic control correlates with poorer attention.
• Early diabetes diagnosis and intervention are crucial for mitigating dementia risk in this population.