Researchers from Boston University School of Medicine (BUSM) have found a significant association between abdominal fat and lower total brain volume. The study, which currently appears in the Annals of Neurology, may improve understanding of the mechanisms underlying the relationship of obesity with dementia and could lead to prevention strategies.
Global body mass and obesity, particularly in midlife, are associated with an increased risk of dementia and Alzheimer disease. Different fat compartments carry differential metabolic risks and there is growing evidence that abdominal obesity and visceral fat are more correlated with vascular risk than global body mass. However, limited data exists demonstrating this concept in association with cognition and dementia.
The BUSM researchers studied more than 700 participants from the Framingham Offspring Cohort. The participants underwent a volumetric multi-detector abdominal CT-scan with quantitative measurement of subcutaneous fat and visceral fat volume as well as a brain MRI.
“We observed an inverse association of body mass index, waist circumference, subcutaneous adipose tissue and visceral adipose tissue with total brain volume, independent of vascular risk factors,” said senior author Sudha Seshadri, MD, an associate professor of neurology at BUSM and an Investigator at the Framingham Heart Study. “More importantly our data suggests that the association between visceral adipose tissue and total brain volume was the strongest and most robust of all, and was also independent of body mass index and insulin resistance,” she added.
According to the researchers, the potential mechanisms underlying the inverse association of obesity and particularly visceral abdominal fat with total brain volume are speculative. Inflammation could be an important mediator as well as diabetes and insulin resistance. In addition, the researchers believe adipose-tissue derived hormones, such as adiponectin, leptin, resistin or ghrelin, could also play a role in the relation between adipose tissue and brain atrophy.
“Although these findings are preliminary they could improve our understanding of the mechanisms underlying the relationship of obesity with dementia with potentially important implications for prevention strategies,” added Seshadri.
Funding for this study was provided by the Framingham Heart Study’s National Heart, Lung, and Blood Institute contract and by grants from the National Institute of Neurological Disorders and Stroke and from the National Institute on Aging.