Measurement of Brain Metabolites in Patients with type 2 Diabetes and Major Depression Using Proton Magnetic Resonance Spectroscopy

Abstract

Type 2 diabetes and major depression are disorders that are mutual risk factors and may share similar pathophysiological mechanisms. To further understand these shared mechanisms, the purpose of our study was to examine the biochemical basis of depression in patients with type 2 diabetes using proton MRS. Patients with type 2 diabetes and major depression (n ¼ 20) were scanned along with patients with diabetes alone (n ¼ 24) and healthy controls (n ¼ 21) on a 1.5 T MRI/MRS scanner. Voxels were placed bilaterally in dorsolateral white matter and the subcortical nuclei region, both areas important in the circuitry of late-life depression. Absolute values of myoinositol, creatine, N-acetyl aspartate, glutamate, glutamine, and choline corrected for CSF were measured using the LC-Model algorithm. Glutamine and glutamate concentrations in depressed diabetic patients were significantly lower (po0.001) in the subcortical regions as compared to healthy and diabetic control subjects. Myo-inositol concentrations were significantly increased (po0.05) in diabetic control subjects and depressed diabetic patients in frontal white matter as compared to healthy controls. These findings have broad implications and suggest that alterations in glutamate and glutamine levels in subcortical regions along with white matter changes in myo-inositol provide important neurobiological substrates of mood disorders.

White Matter Tract Integrity of Anterior Limb of Internal Capsule in Major Depression and Type 2 Diabetes

“…The FA reduction in the right ALIC implicates that the brain regions connected via ALIC could contribute to the impairment of the white matter integrity, which confirms our earlier results in caudate nuclei using MT and MRS techniques (Kumar et al, 2009;Ajilore et al, 2007). Decreased FA in the ALIC has also been reported in a number of previous studies (Jia et al, 2010;Zhu et al, 2011).…”

“…This finding complements previous studies on frontal WM impairments in diabetes (Ajilore et al, 2007, Hsu et al, 2012. For example, Hsu et al found lower FA values in bilateral frontal WM in type 2 diabetic subjects compared to healthy controls.…”

“…Using proton MRS (magnetic resonance spectroscopy), we further found glutamine and glutamate concentrations in depressed diabetic subjects to be significantly lower in select subcortical regions including the caudate as compared to healthy and diabetic control subjects. Furthermore, myo-inositol concentrations were significantly increased in depressed diabetic subjects as well as diabetic control subjects within the frontal white matter (WM) when compared to healthy controls (Ajilore et al, 2007). Additionally, a recent study by Hsu et al found significantly decreased fractional anisotropy (FA) values in the bilateral frontal WM in type 2 diabetic subjects compared to healthy controls and a significant association between disease duration and microstructural properties in several brain regions including bilateral cerebellum, temporal lobe WM, right caudate, bilateral cingulate gyrus, pons, and parahippocampal gyrus (Hsu et al, 2012).…”

Proton magnetic resonance spectroscopy in children with fetal alcohol spectrum disorders

“…Nevertheless, the increased 1h-Mrs sensitivity is counteracted by its decreased specificity, as similar changes in cerebral metabolites may be found in various central nervous system disorders. For example, MI elevation was also described in the frontal lobe white matter of diabetic patients with and without major depression 32 .…”

Metabolite Differences in the Lenticular Nucleus in Type 2 Diabetes Mellitus Shown by Proton MR Spectroscopy

“…The axial section showing the most anterior extent of the anterior margin of the genu of the corpus callosum was chosen as the reference image on which to center the voxels for both locations. 12 Single-voxel spectroscopy was performed on all subjects with a circularly polarized head coil by using a point-resolved spectroscopy sequence (TR/TE, 1000/144 ms) with 128 averages. Due to the less complex spectra and increased reproducibility of the measurements, the long-TE point-resolved spectroscopy sequence was chosen as the primary pulse sequence.…”