Cerebral Blood Flow Abnormalities in Brain Regions Responsible for Cognitive Function in Type 2 Diabetes

Abstract

Aim: The risk of developing mild cognitive impairment (MCI) increases with type 2 diabetes (T2DM). Brain morphometric changes associated with MCI have been described. However Cerebral Blood Flow (CBF) changes in relation to MCI has not been fully investigated. This study aims to investigate regional CBF changes in subjects with T2DM and MCI. Method: Seventy-four age and gender matched subjects [28, T2DM (T2DM); 17, T2DM+MCI (T2DM/MCI) and 29, healthy volunteers (HV)] were recruited. All subjects underwent clinical and questionnaire (Addenbrooke’s Cognitive Assessment [ACE-R]) assessment along with Arterial Spin Labelling (ASL) perfusion Magnetic Resonance Imaging (MRI) of the brain. The ASL data was modelled to yield quantitative arterial CBF maps in neuroanatomical regions involved with cognitive function. Results: Demographic data revealed aged-matched participants between all three groups (mean age 69.3-71.5 years, ANOVA, p = 0.164). Mean age of last education was significantly lower in the T2DM/MCI group (mean±SD;15.1 ±0.9 when compared to the other groups (HV 19.3±5.6, T2DM 17.1±2.9) Kruskal-Wallis, p=0.003. T2DM/MCI ACE-R score (mean±SD; 83±4) was significantly lower compared to other groups (HV=96±2, T2DM=94±3; ANOVA p<0.001). There was significantly lower CBF in T2DM/MCI compared to T2DM and HV in the medial temporal lobes (CBF 76.8 ml/100g/min, ANOVA p<0.05), insula (CBF 67.5 ml/100g/min ANOVA p<0.005), and frontal lobes (CBF 71.8 ml/100g/min, ANOVA p<0.005)<bold>. </bold>Pearson’s correlation revealed significant correlations between ACE-R score and regional CBF measurements in the medial temporal lobes, (p<0.05, r=.25) thalamus (p<0.05, r=.23) and insula (p<0.05, r=.29). Conclusion: This study demonstrates significantly lower CBF in T2DM MCI subjects in neuroanatomical regions responsible for cognitive function. This may be essential to help understand the pathological mechanisms that occur behind the increased risk of developing cognitive impairment in T2DM. Disclosure L. Hunt: None. D. Selvarajah: None. S. Tesfaye: Speaker's Bureau; Self; Pfizer Inc.. Other Relationship; Self; Janssen Pharmaceuticals, Inc., Takeda Development Centre Europe Ltd.. Advisory Panel; Self; Wörwag Pharma GmbH & Co. KG. I.D. Wilkinson: None.