OBJECTIVETo evaluate the changes in subcortical white matter and corpus callosum volumes in patients with type 2 diabetes mellitus (T2DM).

METHODSHigh resolution three-dimensional T1-weighted fast spoiled gradient recalled echo magnetic resonance images were obtained from 16 T2DM patients and 16 normal controls, and 11 T2DM patients also received the same magnetic resonance imaging scans after insulin therapy for 1 year. Volumetric analysis was performed and analysis of covariance and paired t test were applied.

RESULTSA lower volume was demonstrated in T2DM patients than that in the normal controls in bilateral caudal middle frontal lobe, bilateral pars opercularis, right inferior parietal lobe, right inferior temporal lobe, right middle temporal lobe, and left transverse temporal lobe (all P<0.05). After insulin therapy for 1 year, the increased subcortical white matter of brain regions were demonstrated in left medial orbitofrontal lobe, right caudal middle frontal lobe, right inferior parietal lobe, right lingual lobe, right inferior temporal lobe, right middle temporal lobe, left transverse temporal lobe, left entorhinal lobe and left insular lobe at the follow-up level in T2DM patients compared with baseline level (P<0.05). The decreased volumes of subcortical white matter were observed in the bilateral paracentral lobe, right superior forntal lobe and right precuneus lobe in T2DM patients on insulin therapy for 1 year (P<0.05). A decreased trend of subcortical white matter was involved in corpus callosum (P>0.05) and a significant decreased volume was demonstrated in the middle posterior part of corpus callosum after insulin therapy for 1 year(P<0.05).

CONCLUSIONST2DM patients have decreased subcortical white matter of multiple brain regions, and the atrophy of subcortical white matter can be improved by the insulin therapy. The volume analysis of subcortical white matter is a simple and effective tool for the evaluation of white matter damage in T2DM patients.