Insulin sensitivity as a mediator of the relationship between BMI and working memory-related brain activation

Mitzi M. Gonzales, Takashi Tarumi, Steven C. Miles, Hirofumi Tanaka, Furqan Shah, Andreana P. Haley

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

Midlife obesity is associated with cognitive deficits and cerebral atrophy in older age. However, little is known about the early signs of these deleterious brain effects or the physiological mechanisms that underlie them. Functional magnetic resonance imaging (fMRI) allows us to detect early changes in brain response to cognitive challenges while behavioral performance is still intact. Accordingly, we examined the impact of obesity on functional activation during a 2-Back task in 32 cognitively normal middle-aged adults, who were classified into normal, overweight, and obese groups according to BMI. Additionally, we examined insulin sensitivity as a potential mediator of the relationship between BMI and brain activation. Insulin sensitivity is of special interest because insulin is strongly associated with both obesity and central nervous system functioning. Group differences in task-related brain activation were examined in a priori regions of interest (ROIs) using ANOVA. The obese BMI group displayed significantly lower task-related activation in the right parietal cortex, BA 40/7, (F(2,29) = 5.26, P = 0.011) than the normal (P = 0.016) and overweight (P = 0.047) BMI groups. Linear regression and bootstrapping methods for assessing indirect effects indicated that insulin sensitivity fully mediated the relationship between task-related activation in the right parietal cortex and BMI ((F(3,28) = 9.03, P = 0.000), Β = 0.611, P = 0.001, 95% confidence interval: 2.548 to 0.468). In conclusion, obesity in middle age was related to alterations in brain activation during a cognitive challenge and this association appeared to be mediated by insulin sensitivity.

Original languageEnglish (US)
Pages (from-to)2131-2137
Number of pages7
JournalObesity
Volume18
Issue number11
DOIs
StatePublished - Nov 1 2010

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Short-Term Memory
Insulin Resistance
Obesity
Brain
Parietal Lobe
Atrophy
Linear Models
Analysis of Variance
Central Nervous System
Magnetic Resonance Imaging
Confidence Intervals
Insulin

ASJC Scopus subject areas

  • Endocrinology
  • Medicine (miscellaneous)
  • Endocrinology, Diabetes and Metabolism
  • Nutrition and Dietetics

Cite this

Gonzales, M. M., Tarumi, T., Miles, S. C., Tanaka, H., Shah, F., & Haley, A. P. (2010). Insulin sensitivity as a mediator of the relationship between BMI and working memory-related brain activation. Obesity, 18(11), 2131-2137. https://doi.org/10.1038/oby.2010.183

Insulin sensitivity as a mediator of the relationship between BMI and working memory-related brain activation. / Gonzales, Mitzi M.; Tarumi, Takashi; Miles, Steven C.; Tanaka, Hirofumi; Shah, Furqan; Haley, Andreana P.

In: Obesity, Vol. 18, No. 11, 01.11.2010, p. 2131-2137.

Research output: Contribution to journalArticle

Gonzales, MM, Tarumi, T, Miles, SC, Tanaka, H, Shah, F & Haley, AP 2010, 'Insulin sensitivity as a mediator of the relationship between BMI and working memory-related brain activation', Obesity, vol. 18, no. 11, pp. 2131-2137. https://doi.org/10.1038/oby.2010.183
Gonzales, Mitzi M. ; Tarumi, Takashi ; Miles, Steven C. ; Tanaka, Hirofumi ; Shah, Furqan ; Haley, Andreana P. / Insulin sensitivity as a mediator of the relationship between BMI and working memory-related brain activation. In: Obesity. 2010 ; Vol. 18, No. 11. pp. 2131-2137.
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