A new study presented at RSNA 2024 shows visceral fat accumulation in midlife correlates with Alzheimer's disease markers decades before symptoms appear. Researchers found visceral fat accounts for 77% of the relationship between high BMI and amyloid accumulation.
The study examined 80 cognitively normal middle-aged individuals (average age: 49.4 years, 62.5% female, BMI: 32.31, 57.5% obese) using brain PET scans, body MRI, metabolic assessments including glucose/insulin measurements, and lipid panels.
"Our study showed that higher visceral fat was associated with higher PET levels of the two hallmark pathologic proteins of Alzheimer's disease—amyloid and tau," said lead author Mahsa Dolatshahi, MD, MPH, from Mallinckrodt Institute of Radiology.
Key findings included significant associations between amyloid burden and:
- Visceral adipose tissue (VAT)
- Insulin resistance (HOMAIR)
- Subcutaneous adipose tissue (SAT)
- Body Mass Index (BMI)
Notably, higher insulin resistance and lower HDL cholesterol were associated with increased amyloid, though higher HDL levels partially reduced visceral fat's effects on amyloid pathology.
"Knowing that visceral obesity negatively affects the brain opens up the possibility that treatment with lifestyle modifications or appropriate weight-loss drugs could improve cerebral blood flow and potentially lower the burden of and reduce the risk for Alzheimer's disease," said senior author Cyrus A. Raji, MD, PhD.
A companion study demonstrated that increased visceral fat was linked to reduced cerebral blood flow, particularly in the bilateral Calcarine gyri and left middle temporal lobe.
The research has significant public health implications, as an estimated 6.9 million Americans aged 65 and older live with Alzheimer's disease—a number projected to reach 13 million by 2050 without medical breakthroughs.
The research received the RSNA Trainee Research Prize.