Resting-State Brain Functional Connectivity Is Altered in Type 2 Diabetes

• Published in: Diabetes (New York, N.Y.) Vol. 61; no. 9; pp. 2375 - 2379
• Main Authors: MUSEN, Gail, JACOBSON, Alan M, BOLO, Nicolas R, SIMONSON, Donald C, SHENTON, Martha E, MCCARTNEY, Richard L, FLORES, Veronica L, HOOGENBOOM, Wouter S
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Diabetes Association 01-09-2012
• Subjects: Aged; Alzheimer's disease; Analysis; Atrophy; Biological and medical sciences; Brain; Brain - physiopathology; Brain mapping; Cognition; Cognition & reasoning; Cognitive ability; Complications; Diabetes; Diabetes Mellitus, Type 2 - physiopathology; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Executive function; Female; Frontal Lobe - physiopathology; Glucose; Hippocampus - anatomy & histology; Hippocampus - physiopathology; Homeostasis; Humans; Insulin Resistance; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Medical sciences; Middle Aged; Models, Biological; Software; Temporal Lobe - physiopathology; Thalamus - physiopathology; Type 2 diabetes; Endocrinopathy; Type 2 diabetes; Metabolic diseases; Central nervous system; Encephalon
• ISSN: 0012-1797; 1939-327X
• DOI: 10.2337/db11-1669

Type 2 diabetes mellitus (T2DM) is a risk factor for Alzheimer disease (AD). Populations at risk for AD show altered brain activity in the default mode network (DMN) before cognitive dysfunction. We evaluated this brain pattern in T2DM patients. We compared T2DM patients (n = 10, age = 56 ± 2.2 years, fasting plasma glucose [FPG] = 8.4 ± 1.3 mmol/L, HbA(1c) = 7.5 ± 0.54%) with nondiabetic age-matched control subjects (n = 11, age = 54 ± 1.8 years, FPG = 4.8 ± 0.2 mmol/L) using resting-state functional magnetic resonance imaging to evaluate functional connectivity strength among DMN regions. We also evaluated hippocampal volume, cognition, and insulin sensitivity by homeostasis model assessment of insulin resistance (HOMA-IR). Control subjects showed stronger correlations versus T2DM patients in the DMN between the seed (posterior cingulate) and bilateral middle temporal gyrus (β = 0.67 vs. 0.43), the right inferior and left medial frontal gyri (β = 0.75 vs. 0.54), and the left thalamus (β = 0.59 vs. 0.37), respectively, with no group differences in cognition or hippocampal size. In T2DM patients, HOMA-IR was inversely correlated with functional connectivity in the right inferior frontal gyrus and precuneus. T2DM patients showed reduced functional connectivity in the DMN compared with control subjects, which was associated with insulin resistance in selected brain regions, but there were no group effects of brain structure or cognition.