Abstract

Objective: This study used neurocognitive assessment and neuroimaging to examine brain function in youth with type 1 diabetes studied prospectively from diagnosis.

Objective: Research Design and Methods

Participants: Type 1 diabetes (N=106) and controls (N=75) with no significant group difference on IQ at baseline 12 years previously.

Measures: Wechsler Abbreviated Scale Intelligence, magnetic resonance spectroscopy and imaging, metabolic control data from diagnosis.

Results: Type 1 diabetes had lower Verbal and Full Scale IQ than controls (both p<·05). Type 1 diabetes had lower N-acetylaspartate in frontal lobes and basal ganglia and higher myoinositol and choline in frontal, temporal lobes and basal ganglia than controls (all p<·05). Type 1 diabetes, relative to controls, had decreased grey matter in bilateral thalami and right parahippocampal gyrus and insular cortex. White matter was decreased in bilateral parahippocampi, left temporal lobe and middle frontal area (all p<·0005 uncorrected). T2 in type 1 diabetes was increased in left superior temporal gyrus and decreased in bilateral lentiform nuclei, caudate nuclei and thalami, and right insular area (all p<·0005 uncorrected). Early onset disease, predicted lower Performance IQ, hypoglycemia was associated with lower Verbal IQ and volume reduction in thalamus, poor metabolic control predicted elevated myoinositol and decreased T2 in thalamus and older age predicted volume loss and T2 change in basal ganglia.

Conclusions: This study documents brain effects 12 years after diagnosis in a type 1 diabetes sample whose IQ at diagnosis matched that of controls. Findings suggest several neuropathological processes including gliosis, demyelination and altered osmolarity.