Hippocampal volume is related to body mass index in Alzheimerʼs disease

Obesity is associated with lower brain volumes in early Alzheimerʼs disease, but its effects on hippocampal volumes are unclear, as weight loss is also associated with Alzheimerʼs disease. To address this question, we applied an automated hippocampal mapping method to brain MRI scans for 162 patients with Alzheimerʼs disease. We hypothesized that obesity, measured by body mass index, would be associated with lower hippocampal volumes in mildly affected patients. Statistical maps showed a selective pattern of hippocampal volume differences that were significantly associated with body mass index. Associations were detected in the anterior hippocampus, and confirmed by permutation testing. Cardiovascular risk factors, such as high body mass index, may promote additional neurodegenerative changes, and should therefore be considered in epidemiological studies and clinical trials.