Dysglycemia, brain volume and vascular lesions on MRI in a memory clinic population

Abstract

Objective: It is unclear, if the association between abnormalities in glucose metabolism (dysglycemia) and impaired cognitive functioning is primarily driven by degenerative or vascular brain damage. We therefore examined the relation between dysglycemia and brain volume and vascular lesions on MRI in a memory clinic population.

Methods: The relations between markers of glycemia (HbA1c and fasting glucose levels) and normalized brain volume, medial temporal lobe atrophy and vascular lesions (white matter hyperintensities, lacunes) were assessed in 274 consecutive patients attending a memory clinic, using linear regression analyses.

Results: Clinical diagnoses were subjective complaints (n=117), mild cognitive impairment (n=62), Alzheimer's disease (n=61) and other type of dementia (n=34). Twenty patients had a history of diabetes. Across the whole study population there was no relation between HbA1c or fasting glucose and the brain MRI measurements, after adjustments for age, sex and diagnostic group. Secondary analyses after stratification by diabetes status, diagnosis and median age (67 years) did not change the results.

Conclusion: In this memory clinic population, dysglycemia was not associated with either brain volume or vascular lesions. Apparently, dysglycemia is not associated with a specific class of brain pathology in patients with cognitive complaints.

Keywords: Alzheimer's disease; Brain atrophy; Diabetes; Glucose; HbA1c; Hippocampus; Lacunes; Mild cognitive impairment; White matter hyperintensities.