Is obesity a risk factor for Alzheimer’s disease?

Obesity and Alzheimer

It has been established that middle-age obesity is a risk factor for Alzheimer’s disease, but the results from studies in older people are contradictory. Our recent study would explain the discrepancies on this topic.

This work is the result of a collaborative effort between the Neuroimage team of the Sant Pau Memory Unit and the Obesity Unit of Hospital Clinic in Barcelona. The results of this study add to previous collaborations between both groups and have been published in the Aging section of the Oncotarget journal and entitled:  “Obesity and Alzheimer’s disease, does the obesity paradox really exist? A magnetic resonance imaging study”.

Obesity and Alzheimer - Sant Pau Memory Unit - Alzheimer Research - Barcelona

What was done in this study?

We analyzed biometric (weight, height, body mass index) and neuroimaging (structural MRI) data from 162 cognitively healthy elderly from the ADNI study. We measured the relationship between biometric variables and brain cortical thickness at the beginning of the study and during follow-up.

Main results

Participants that had suffered unintentioal weight loss during follow-up experienced greater cortical atrophy that was directly correlated with their body mass index. In those participants without significant weight loss, this relationship was inverse. Specifically, our results show an interaction effect between body mass index and weight loss in large structural brain areas, also in those regions that are typically affected by Alzheimer’s disease.

Relevance of the study

Our results suggest that obesity is associated with a higher risk of developing the structural brain changes typically associated with Alzheimer’s disease but only in the presence of unintentional weight loss.

These results are helpful to understand the discordances between previous studies and to clarify that weight loss acts as a confounder factor in the relationship between obesity and the risk of Alzheimer’s disease in the elderly.

More information

Obesity and Alzheimer’s disease, does the obesity paradox really exist? A magnetic resonance imaging study. Pegueroles J & Jiménez A et al. Oncotarget 2018

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