Mild Cognitive Impairment Common in Newly Diagnosed Type 2 Diabetes, Linked to C-peptide and Smoking
Background
Mild cognitive impairment (MCI) is a significant concern in Type 2 Diabetes Mellitus (T2DM), with prevalence of Alzheimer's Disease (AD) being 1.5 to 2.5 times higher in T2DM patients. However, data on MCI prevalence and dynamics in newly diagnosed T2DM patients without overt vascular complications is limited. Understanding early risk factors is crucial, as high glucose levels in diabetes can increase glucose metabolism via glycolysis, leading to elevated lactate production and O-GlcNAcylation, which are implicated in cognitive decline. This study addresses the gap by examining MCI in early, uncomplicated T2DM.
Study Design
Researchers prospectively followed 937 adults with newly diagnosed Type 2 Diabetes Mellitus who had no baseline microvascular or macrovascular complications. The cohort was observed for a mean of 62.7±21.5 months. Cognitive status was assessed using the Montreal Cognitive Assessment (MoCA), with MCI defined by MoCA-defined cognitive impairment. The study evaluated baseline MCI prevalence, remission rates among those with MCI, and incidence among cognitively normal patients. Multivariable models identified clinical correlates, including C-peptide levels, smoking status, uric acid, and participation in therapeutic patient education.
Results
At baseline, 286 patients (30.5%) were diagnosed with mild cognitive impairment. During the mean 62.7-month follow-up period, 43 out of 286 patients (15.0%) with baseline MCI experienced remission. Conversely, 96 out of 651 initially cognitively normal patients (14.7%) developed incident MCI. > Higher C-peptide levels were strongly associated with prevalent MCI, and continuous C-peptide remained significantly associated with Montreal Cognitive Assessment performance in multivariable analyses. Smoking was linked to a less favorable cognitive profile, while uric acid showed an inverse association with prevalent MCI. Participation in therapeutic patient education was independently associated with a lower risk of incident MCI, and incident retinopathy was also associated with incident MCI.
Key Findings
- 30.5% of newly diagnosed T2DM patients without complications presented with mild cognitive impairment at baseline.
- Over 62.7 months, 15.0% of patients with baseline MCI experienced remission.
- 14.7% of initially cognitively normal patients developed incident mild cognitive impairment.
- Higher C-peptide levels were strongly associated with prevalent MCI and poorer
MoCAperformance. - Smoking was linked to a less favorable cognitive profile, while therapeutic patient education reduced incident MCI risk.
Why It Matters
This study highlights that MCI is common and dynamic even in early, uncomplicated T2DM, suggesting the need for early cognitive screening. Optimizing metabolic control, particularly C-peptide levels, and addressing behavioral factors like smoking and patient education, could be crucial for preserving cognitive function. For individuals with newly diagnosed T2DM, proactive engagement in therapeutic patient education programs may offer a tangible benefit in reducing MCI risk. While this is an observational study, it underscores the importance of a holistic approach to T2DM management beyond just glycemic control, emphasizing lifestyle and education as potential cognitive protective strategies.
type-2-diabetes
mild-cognitive-impairment
cognition
c-peptide
smoking
retinopathy