Insulin resistance and executive dysfunction in older persons

J Am Geriatr Soc. 2004 Oct;52(10):1713-8. doi: 10.1111/j.1532-5415.2004.52466.x.


Objectives: To evaluate the association between insulin resistance (IR) and executive dysfunction in a large, population-based study of older persons without diabetes mellitus (DM) or dementia.

Design: Cross-sectional study.

Setting: Outpatient clinic in Greve in Chianti and Bagno a Ripoli, Italy.

Participants: A total of 597 subjects aged 65 to 93 without DM or dementia.

Measurements: Anthropometric measurements; plasma fasting levels of glucose, insulin, cholesterol (total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol), and insulin-like growth factor-1 (IGF-1); homeostasis model assessment (HOMA) to estimate degree of IR; Trail Making Test (TMT) A; TMT-B; TMT-B minus TMT-A (DIFF B-A); and Mini-Mental State Examination (MMSE).

Results: IR (HOMA) was associated with longer TMT-B (correlation coefficient (r)=0.11; P=.006) and DIFF B-A times (r=0.10; P=.022). Subjects in the upper tertile of IR were older and had longer TMT-B and DIFF B-A than participants in the lowest tertile. After adjusting for age, sex, and years of formal education, IR was significantly correlated with TMT-A, TMT-B, and DIFF B-A. After adjusting for age, sex, education, body mass index, waist:hip girth ratio, HDL-C, triglycerides, IGF-1, hypertension, drug intake, and physical activity, the results did not significantly change. After introducing MMSE score into the model, IR continued to be an independent determinant of TMT-A (beta=11.005; P=.021), TMT-B (beta=28.379; P<.001), and DIFF B-A (beta=17.374; P=.011).

Conclusion: IR is independently associated with frontal cortex function evidenced by poor TMT times in older persons without DM or dementia.

MeSH terms

  • Adult
  • Aged
  • Aging / metabolism*
  • Blood Glucose
  • Cognition*
  • Cross-Sectional Studies
  • Dementia / diagnosis
  • Female
  • Geriatric Assessment / methods*
  • Homeostasis
  • Humans
  • Insulin Resistance*
  • Italy
  • Linear Models
  • Male
  • Middle Aged
  • Trail Making Test


  • Blood Glucose