Adipose Tissue Distribution in Patients with Alzheimer's Disease: A Whole Body MRI Case-Control Study

Total and central adiposity have been associated with increased risk of Alzheimer's disease (AD). Visceral and subcutaneous adipose tissues have different metabolic characteristics and could therefore be differentially associated with AD.

To compare regional fat distribution determined by magnetic resonance imaging (MRI) in AD patients and healthy controls and investigate associations with stage of the disease and chemical markers. The investigation was performed in a prospective case-control study.

We examined thirty patients with mild to moderate AD by whole-body MRI (1.5 T) and clinical questionnaires in comparison to thirty cognitively healthy age- and gender-matched study participants. Volumes of total, subcutaneous, and visceral body fat tissue were determined by an unbiased automatic analysis algorithm. Levels of leptin, ghrelin, and adiponectin were determined in serum, amyloid-β (Aβ)(1-42) and tau protein levels in cerebrospinal fluid (CSF).

Male AD patients displayed significantly more total fat tissue than male controls. This difference was not observed in women. We observed a trend toward higher volume of visceral fat tissue in all patients (p = 0.13). Severity of disease was not associated with fat distribution in our study. Increased leptin levels correlated with lower CSF Aβ(1-42) in female, but not in male, AD patients.

Fat volume is increased in male, but not in female AD patients. Negative correlation of leptin levels and CSF Aβ(1-42) in females might be one co-factor for the increased AD risk of females. Further studies are required to confirm this gender difference in fat volume during AD and evaluate its pathophysiological importance.