Total body and arm bioimpedance in patients with Alzheimer's disease

To analyse body composition of patients with Alzheimer's disease (AD) using total body and localized specific bioelectrical impedance vector analysis (specific BIVA).

127 patients (50 men, 78.2±6.3years; 77 women, 81.4±6.8years) with mild to moderate stages of AD were selected from the Geriatric Division, SS. Trinità Hospital of Cagliari (Italy). A sample of 135 healthy age-matched individuals (74 men, 77.4±5.3years; 61 women, 80.4±5.5years) was chosen as control group. Anthropometric measurements were taken and body mass index (BMI) was calculated. Bioelectrical measurements were taken on the right side of the body for both the whole-body and the arm, using a BIA 101 analyser (Akern). Body composition was assessed by means of specific bioelectrical impedance vector analysis (specific BIVA). The comparison between patients and the control group was performed by two-factor analysis of variance and Hotelling's T² test.

In comparison with the control group, patients with AD showed similar anthropometric characteristics, including BMI, but lower lean tissue mass and higher percent fat mass, as indicated by the lower phase angles and longer specific vectors. The same body composition peculiarities were detected considering only the right arm.

Patients with AD show characteristics - lower lean mass/higher percent fat mass - that can be detected by both total body and localized bioimpedance approaches. This suggests the possibility of a new, quicker and simpler procedure for body composition assessment.