A study presented at the RSNA 2024 congress reports a link between obesity, the resulting metabolic dysfunctions and the onset of Alzheimer’s disease. Researchers have recommended lifestyle modifications aimed at reducing visceral and subcutaneous fat in particular and thus fundamentally treating this neurodegenerative disease.
According to the Alzheimer’s Association, approximately 6.9 million Americans aged 65 and older are living with Alzheimer’s disease, a number that could reach 13 million by 2050 unless medical advances prevent or cure it. the disease. Firstly, lifestyle changes to limit the risk of obesity and ensure better distribution of body fat during the young years of life.
Researchers are trying to identify a link between obesity and the onset of Alzheimer’s disease
American researchers presented a topic on this theme at the RSNA 2024 congress. They focused on the link between modifiable lifestyle factors and the pathology of Alzheimer’s disease. This work included 80 cognitively normal middle-aged people (mean age: 49.4 years, women: 62.5%), of whom 57.5% were obese with a mean BMI of 32.31. They underwent a PET scan, a body MRI and a metabolic assessment (glucose, insulin and cholesterol). Abdominal MRI was used in particular to measure the volume of subcutaneous and visceral fat.
« We have studied the pathology of Alzheimer’s disease as early as midlife, in the 1940s and 1950s, when it is in its early stages and potential changes such as weight loss and reduction in visceral fat are more effective as a means of preventing or delaying the onset of diseaseannounces the lead author of the study, Dr. Mahsa Dolatshahi, postdoctoral research associate at the Mallinckrodt Institute of Radiology (MIR) at the Washington University School of Medicine in St. Louis (Missouri – USA). We assessed patients’ BMI, visceral fat, subcutaneous fat, and insulin resistance or HDL and compared these parameters to amyloid and tau deposition in Alzheimer’s disease. ».
PET and MRI to accurately assess visceral and subcutaneous fat volumes
Thigh muscle scans have also been used to measure muscle and fat volume. Alzheimer’s disease pathology was measured using PET with tracers that bind to amyloid plaques and Tau protein tangles that accumulate in the brains of people with Alzheimer’s disease. The results revealed that higher levels of visceral fat were linked to increased amyloid. Other types of fat do not explain the increase in Alzheimer’s pathology linked to obesity.
« To our knowledge, our study is the only one to demonstrate these results at midlife, where our participants are several decades away from developing the first symptoms of dementia resulting from Alzheimer’s disease.adds Dr Dolatshahi. » The study also showed that higher insulin resistance and lower HDL levels were associated with higher amyloid levels in the brain. The effects of visceral fat on amyloid pathology were partially reduced in people with higher HDL levels.
Work that could have a considerable impact on American public health
« A key implication of our work is that managing Alzheimer’s risk in obesity will need to involve targeting the associated metabolic and lipid problems that often occur with higher body fat. », continues the co-senior author of the study, Professor Cyrus A. Raji, associate professor of radiology at MIR.
« This work will have a significant impact on public health because nearly three in four Americans are overweight or obese.concludes Dr Raji. The fact that visceral obesity negatively affects the brain opens the possibility that treatment with lifestyle modifications or appropriate weight-loss medications could improve cerebral blood flow and potentially reduce the burden and risk of Alzheimer’s disease. . »
Paolo Royan
Health
