In a publication by Aging and Disease, a pilot study funded by the NIA uncovered that mid-aged individuals with abdominal obesity exhibited greater early signs of Alzheimer’s, such as increased beta-amyloid deposits and reduced cortical thickness. Despite the known association between midlife obesity and Alzheimer’s, there’s debate over whether a high body mass index (BMI) consistently predicts disease onset. To scrutinize this issue, investigators from Washington University in St. Louis analyzed the connection between abdominal obesity and Alzheimer’s risk. Abdominal obesity is characterized by an excessive accumulation of fat deep within the abdominal cavity, surpassing subcutaneous fat.
The study engaged 32 cognitively intact, middle-aged adults, ranging from 40 to 60 years in age. Researchers considered factors like BMI, insulin resistance, and applied MRI scans to quantify abdominal fat, offering a more direct measurement of obesity than the traditional BMI metric.
Findings indicated that abdominal obesity was more prevalent in men than women, with no detected gender disparity in BMI levels or insulin resistance—a condition tied to obesity and potentially a factor in the development of Alzheimer’s.
Examination of neuroimaging data revealed that heightened body mass index (BMI), central adiposity, and elevated insulin resistance metrics correlate with reduced cortical volume in the temporal lobe and other areas vulnerable to Alzheimer’s degradation.
In males, excessive abdominal fat was notably associated with increased deposits of beta-amyloid in the precuneus cortex, a brain region Alzheimer’s typically impacts in its initial stages.
However, the study found no significant relationship between BMI, abdominal fat, or insulin resistance with the accumulation of tau proteins or overall brain volume reduction, another hallmark of Alzheimer’s pathology. This absence might indicate that the link between central obesity and both beta-amyloid presence and diminished cortical thickness could act as early indicators, manifesting prior to tau protein accumulation and cognitive impairment.
These preliminary findings endorse the premise that abdominal obesity may serve as an indicative marker for Alzheimer’s risk evaluation. The research team is set to enlist 20 additional participants for the forthcoming stage of their inquiry.