Mild cognitive impairment (MCI) is increasingly recognized as a chronic complication of type 1 diabetes mellitus (T1DM), although the metabolic mechanisms underlying cognitive dysfunction remain incompletely understood. A cross-sectional study published in the Journal of Diabetes and Its Complications evaluated whether alterations in amino acid metabolism were associated with T1DM-related MCI and assessed potential metabolic markers linked to cognitive impairment.

The study enrolled 119 participants, including 39 individuals with T1DM-associated MCI (T1DM-MCI), 48 with T1DM and normal cognition (T1DM-NC), and 32 healthy controls. MCI was defined as a Montreal Cognitive Assessment (MoCA) score <26. Serum amino acid profiles were analyzed using ultra-performance liquid chromatography-tandem mass spectrometry. 

Findings

• The mean participant age was 36 years, and 44% of participants were women.
• Among individuals with T1DM, the median disease duration was 7 years.
• Older age (odds ratio [OR] 1.060; P = 0.008) and lower educational level (OR 0.851; P = 0.038) were significantly associated with T1DM-MCI.
• Compared with the T1DM-NC group, 7 metabolites were significantly downregulated in the T1DM-MCI group.
• L-valine differentiated T1DM-MCI from T1DM-NC with moderate diagnostic performance, showing sensitivity of 72.7%, specificity of 75.7%, and area under the curve of 0.745 (P < 0.001).

Adults with T1DM-associated MCI showed altered amino acid metabolic profiles, including lower circulating levels of several metabolites. The findings suggest amino acid metabolism may contribute to cognitive dysfunction in T1DM and may support future biomarker-based approaches for identifying cognitive impairment.