Brain lesions on MRI in elderly patients with type 2 diabetes mellitus

Background and Purpose: Diabetes mellitus (DM) type 2 has been associated with poor cognitive performance and dementia, particularly in elderly patients. The exact mechanisms underlying the cognitive dysfunction in DM remain unclear. Imaging studies of the brain could be helpful to give more insight into possible structural brain lesions underlying these cognitive dysfunctions. Therefore, we performed a study in independently living patients with DM type 2 in order to investigate the association between DM and brain imaging abnormalities. Methods: The study population consisted of 45 patients with DM type 2 without hypertension (mean age 73.4 ± 5.1 years, mean duration 16.5 ± 11.5 years), 45 patients with DM type 2 and hypertension (mean age 73.5 ± 6.1 years, mean duration 11.9 ± 9.2 years) and 44 control subjects (mean age 73.1 ± 5.4 years). All patients and control subjects underwent an MRI of the brain. White matter lesions (WML), cerebral atrophy and medial temporal lobe atrophy were rated by a standardized visual rating scale. Lacunar infarcts were defined as focal hypo-intensities on fluid-attenuated inversion recovery sequences with a hyperintense rim around it. Results: WML occurred more frequently in diabetic patients with hypertension as well as without hypertension. Significantly more deep WML were found in DM patients with and without hypertension when compared to control subjects, whereas no difference was found in the occurrence of periventricular hyperintensities. In all 3 groups, lacunar infarcts occurred sporadically. A trend towards higher atrophy scores was seen in patients with DM compared to control subjects. Conclusions: The data of this cross-sectional study suggest that type 2 DM is an independent risk factor for deep WML in the independently living elderly patients.