Cognitive impairment in nondiabetic middle-aged and older adults is associated with insulin resistance

Abstract

To determine whether the cognitive impairments observed in adults with type 2 diabetes mellitus (T2DM) exist in preclinical disease, we compared 38 adult participants with evidence of insulin resistance (IR) to 54 age-, gender-, and education-matched control participants on a battery of neuropsychological tests. We found that participants with IR had performance reductions in declarative memory and executive functioning. When we examined IR simultaneously with other biomedical indicators with which it co-occurs, only IR itself was associated with declarative memory, and hemoglobin A1c (HbA1c) was associated with executive functioning and working memory. We conclude that individuals with insulin resistance already demonstrate similar reductions in cognitive performance as those described in T2DM.

Keywords:

• Insulin resistance
• Type 2 diabetes
• Cognition
• Glycemic control
• Quantitative insulin sensitivity check index

This study was supported by Grants DK 064087, P30-AG-08051, and NCRR M01 RR00096. None of the authors have any financial or personal conflict of interest. H. Bruehl and V. Sweat were involved in acquisition, analysis, and interpretation of data and preparation of the manuscript. J. Hassenstab was involved in analysis and interpretation of data and preparation of the manuscript. V. Polyakov was involved in preparation of the manuscript. A Convit designed and conceptualized the study and was involved in the preparation of the manuscript.