Integrating Diabetes and Cognitive Care

Diabetes mellitus (DM) is significantly associated with an accelerated rate of cognitive decline in individuals with mild cognitive impairment (MCI), with the most pronounced deterioration observed within the first year of diagnosis. Additionally, patients with diabetes are at a higher risk of progressing from MCI to Alzheimer’s disease (AD) compared to those without diabetes. DM also adversely affects brain regions responsible for cognitive functioning.

This study leveraged data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) to identify the optimal intervention window and potential neurobiological targets to delay or prevent the progression from MCI to AD. The cohort comprised 980 participants diagnosed with MCI, stratified based on diabetes status. All participants underwent neuroimaging and cognitive assessments to monitor the rate of conversion from MCI to AD, as well as changes in brain structure and cognitive performance. Among them, 102 patients with diabetes were matched to 204 non-diabetic individuals.

The study revealed a strong correlation between diabetes and cognitive decline, particularly during the first year of MCI diagnosis. Diabetic patients exhibited significant atrophy and reduced gray matter volume and sulcal depth in multiple brain regions—most notably the nucleus accumbens.

Although no statistically significant difference in overall AD conversion was observed between diabetic and non-diabetic participants over the 11-year follow-up, more diabetic patients progressed to AD within the first 12 months following an MCI diagnosis (8.82% vs. 2.45%). Diabetic individuals also demonstrated worse outcomes on cognitive tests such as the Participant-reported Everyday Cognition Scale Plan (EcogPtPlan), Rey Auditory Verbal Learning Test immediate recall (RAVLT-immediate), and Alzheimer’s Disease Assessment Scale Task 4 (ADASQ4) within the first year.

At baseline, diabetic participants showed inward concavity and mild atrophy of the left nucleus accumbens, which persisted and extended to the right side by the 12-month follow-up. Additional changes were noted in cortical thickness, gyrification index, and sulcal depth throughout the follow-up period.

These findings underscore the first year following MCI diagnosis in diabetic patients as a critical window for intervention. Early and aggressive diabetes management—combined with regular cognitive monitoring—is essential to promptly identify and address neurocognitive changes. Comprehensive care should include lifestyle modifications (e.g., diet and exercise), tight glycemic control, and management of comorbidities to mitigate diabetes-related cognitive decline. Moreover, identifying the specific brain structures affected by diabetes can inform the development of targeted neuroprotective strategies.

Source:  Alzheimers Dement. 2024 Jun 12. doi: 10.1002/alz.13882.