Age, BMI and diabetes as independent predictors of brain hypoperfusion

Background: Cerebral blood flow abnormalities are supposed to be potential risk factors for developing cognitive dysfunctionin the general population. Aging, obesity and type 2 diabetes mellitus are associated with perfusion abnormalities leading tocognitive impairment, neurodegeneration and future development of dementia. In our study, we aimed at identifying independentfactors that contribute to the appearance of regional brain perfusion changes besides those that are already known.Material and methods: Forty-three type 2 diabetic and twenty-six obese patients were enrolled. After the intravenous administrationof 740 MBq 99mTc-hexamethylpropylene amine oxime (HMPAO), all subjects underwent brain perfusion SPECT imagingapplying AnyScan S Flex dual-head gamma camera (Mediso, Hungary). Using Philips Achieva 3T scanner brain resting-statefunctional MRI was also performed. The SPECT and MRI images were co-registered and transformed to the MNI152 atlasspace so that data of the following standard volumes of interest (VOIs) could be obtained: frontal lobe, parietal lobe, temporallobe, occipital lobe, limbic region, cingulate, insula, basal ganglia, cerebrum, limbic system and brain stem. Using the SPSS25 statistical software package, general linear regression analysis, Student’s t-test, and Mann-Whitney U-test were applied forstatistical analyses.Results: Multivariate linear analysis identified that BMI and age are significantly (p < 0.0001) associated with perfusion, andpatient group was slightly above threshold (p = 0.0524). We also found that the presence of diabetes was an independentsignificant predictor of normalized regional brain perfusion only in the insula (p < 0.001). Other independent predictors ofnormalized regional brain perfusion were: age in the insula (p < 0.001) and in the limbic region (p < 0.01), and BMI in thebrain stem (p < 0.01).Conclusions: Age and BMI proved to be general, and diabetes regional predictor of brain hypoperfusion. BMI appeared tobe a novel factor affecting brain perfusion. In one specific region, the insula, we detected a difference between the obese andthe diabetic group. These findings may be significant in the understanding of the development of cognitive impairment inmetabolic diseases