Bioelectrical impedance vector analysis detects low body cell mass and dehydration in patients with Alzheimer's disease.

OBJECTIVES This paper evaluates the nutritional status in patients with mild-moderate and severe Alzheimer's disease (AD) by bioelectrical impedance vector analysis (BIVA). DESIGN Cross-sectional study. SETTING Alzheimer Center, SS. Trinita Hospital, Cagliari, and "Monsignor Angioni" Nursing Home, Quartu Sant'Elena (Cagliari, Italy). PARTICIPANTS 83 free-living patients with mild-moderate Alzheimer's disease (29 men, 54 women), 9 institutionalized women in the severe stage; 468 age-matched controls (202 men, 266 women). MEASUREMENTS Mini Nutritional Assessment (MNA), anthropometric (height, weight, BMI), bioelectrical (R, Xc) and biochemical variables (serum albumin) were assessed. RESULTS Bioelectrical characteristics were significantly different in the patients with mild-moderate AD with respect to controls, indicating low body cell mass (men, T2= 12.8; women, T2=34.9; p < 0.01). Women with severe AD showed low body cell mass and dehydration with respect to patients with mild-moderate AD (T2=17.1; p < 0.01). The phase angle, R/H and Z/H were significantly correlated (p < 0.05) with MNA (phase: r = 0.31; R/H: r =-0.37; Z/H: r =-0.37) and albumin (phase: r=0.47; R/H: r=-0.36; Z/H: r=-0.36). CONCLUSION Alzheimer's disease is characterized by a tendency to malnutrition, present even in the mild-moderate stages, and a tendency to dehydration that appears in the severe stage. The BIVA technique is a promising tool for the screening and monitoring of nutrition and hydration status in Alzheimer's disease.