Increased visceral abdominal fat in midlife is associated with the development of Alzheimer’s disease, according to a study to be presented next week at the Radiological Society of North America (RSNA) annual meeting. Visceral fat is the fat that surrounds your internal organs deep in your abdomen. Researchers have found that this hidden belly fat is linked to changes in the brain up to 15 years before the early memory loss symptoms of Alzheimer’s disease appear.
According to the Alzheimer’s Association, more than 6 million Americans are living with Alzheimer’s disease. By 2050, this number is predicted to increase to nearly 13 million people. One in five women and one in 10 men will develop Alzheimer’s disease during their lifetime.
To identify Alzheimer’s disease risk early, researchers looked at brain MRI volumes, amyloid and tau uptake on positron emission tomography (PET) scans, and body mass index (BMI), obesity, and insulin. The relationship between resistance and abdominal fat (fat) was evaluated. ) Organization of a cognitively normal middle-aged population. Amyloid and tau are proteins that are thought to interfere with communication between brain cells.
While other studies have linked BMI to brain atrophy and higher risk of dementia, no previous studies have linked specific types of fat to actual Alzheimer’s disease proteins in cognitively normal people. Similar studies have not investigated the differential role of visceral and subcutaneous fat in early midlife, particularly with regard to the amyloid pathology of Alzheimer’s disease. ”
Mahsa Dolatshahi, MD, MPH, study author, Postdoctoral Researcher, Mallinckrodt Institute of Radiology (MIR), Washington University School of Medicine, St. Louis
For this cross-sectional study, researchers analyzed data from 54 cognitively healthy participants, ranging in age from 40 to 60 years and with an average BMI of 32. Participants underwent glucose and insulin measurements and a glucose tolerance test. Abdominal MRI is used to measure the volume of subcutaneous fat (subcutaneous fat) and visceral fat. Brain MRI measured cortical thickness in brain areas affected in Alzheimer’s disease. PET was used to examine disease pathology in a subset of 32 participants, focusing on amyloid plaques and tau tangles that accumulate in Alzheimer’s disease.
The researchers found that a higher ratio of visceral fat to subcutaneous fat was associated with higher uptake of amyloid PET tracers in the precuneus cortex. This region is a region known to be affected in the early stages of amyloid pathology in Alzheimer’s disease. This relationship was worse for men than for women. Researchers also found that higher visceral fat measurements were associated with increased inflammatory burden in the brain.
“Several pathways have been suggested to play a role,” Dr. Dorashahi said. “In contrast to the potential protective effects of subcutaneous fat, inflammatory secretion of visceral fat can cause brain inflammation, one of the main mechanisms contributing to Alzheimer’s disease.”
The study results have several important implications for early diagnosis and intervention, said senior author Cyrus A. Raji, MD, associate professor of radiology and neurology and director of neuromagnetic resonance imaging at MIR. I pointed out that I have
“This study highlights an important mechanism by which hidden fat increases the risk of Alzheimer’s disease,” he said. “These brain changes have been shown to occur as early as age 50 on average, and up to 15 years before the earliest memory loss symptoms of Alzheimer’s disease appear.”
Dr. Raji added that the results may indicate that visceral fat is a therapeutic target to modify the risk of future brain inflammation and dementia.
“By moving beyond BMI to better characterize the anatomical distribution of body fat with MRI, we are unrivaled in understanding why this factor may increase risk for Alzheimer’s disease. “The less I look at it, the better I understand it,” he said.
Additional co-authors are Paul K. Commean, BEE, Joseph E. Ippolito, MD, Ph.D., Tammie LS Benzinger, MD, Ph.D., and John C. Morris, MD.
