Lower lean mass and higher percent fat mass in patients with Alzheimer's disease

In this study we analyzed body composition in relation to cognitive and functional status, in a cross-sectional sample of patients with Alzheimer's disease (AD). Seventy individuals (27 men, 78.1±6.5years; 43 women, 80.4±5.6years) with mild-moderate stages of AD (clinical dementia ratings 1 and 2) were selected from the Alzheimer Center, SS. Trinità Hospital, ASL 8 of Cagliari (Italy). Cognitive and psycho-functional status was evaluated using mini-mental state examination (MMSE), activities of daily living (ADL) scale, and geriatric depression scale (GDS). Mini-nutritional assessment (MNA) was applied. Anthropometric measurements were taken and body mass index (BMI) was calculated. Body composition was assessed by means of specific bioelectrical impedance vector analysis (BIVA), using the references for the elderly. In comparison with the reference group, patients with AD showed similar BMI and MNA, but peculiar bioelectrical characteristics: lower phase angles and longer vectors (p<0.05). According to specific BIVA, this bioelectrical pattern is indicative of a reduction of lean tissue mass and an increase of percent fat mass (FM%). A more accentuated lean mass reduction (p < 0.05) was observed in women with worse cognitive status and a FM% increase (p < 0.01) in women with worse functional status. In conclusion, patients with AD had lower lean tissue mass and higher percent fat mass than healthy elderly individuals. In women, this pattern was associated with cognitive and functional decline, as indicated by MMSE and ADL values. Specific BIVA showed to be a suitable technique in the elderly, that could enhance BMI and MNA information in the evaluation of nutritional status.