A new analytical variation of bioelectrical impedance vector analysis (BIVA), called specific BIVA, has shown to be more accurate in detecting changes in fat mass than classic BIVA. To compare classic and specific BIVA in order to identify which is more strongly associated with psycho-functional and nutritional indicators in a group of institutionalised elderly patients with dementia. Cross-sectional study. Fifty-four patients (34 women, 20 men) with dementia in moderately severe to very severe stages and aged 60-95years underwent geriatric nutritional assessment, including body mass index calculations, the Mini Nutritional Assessment, the Geriatric Nutritional Risk Index, and whole body composition analysis. With specific BIVA (unlike with classic BIVA), significant differences were found between women with moderately severe and very severe dementia. In the BIVA conducted for body mass index, the confidence ellipses produced with the classic BIVA approach were highly overlapping; but with specific BIVA, significant differences were observed between the women in different nutritional categories (malnutrition, risk of malnutrition, normal weight and obesity). On the other hand, both approaches distinguished malnourished women from those who were at risk of malnutrition, according to the Mini Nutritional Assessment; and men with a moderate-high risk of malnutrition from men with no risk, on the basis of the Geriatric Nutritional Risk Index. Overall, the findings of the present study suggest that specific BIVA is more effective than classic BIVA in identifying bioelectrical changes associated with psycho-functional and nutritional indicators in institutionalised elderly with dementia.

Although dementia and nutritional status have been shown to be strongly associated, differences in body composition (BC) among older people with dementia have not yet been firmly established. The aim of this study was to assess BC through conventional and vector bioimpedance analysis (BIA and BIVA, respectively) in a sample of institutionalized older men with and without dementia, in order to detect dementia-related BC changes. Forty-one institutionalized men ages ≥ 65 y (23 without dementia [CG] and 18 with dementia [DG]) were measured with BIA and interpreted with BIVA and predictive equations. Age (74.4 and 75.7 y) and body mass index (22.5 and 23.6 kg/m(2)) were similar for DG and CG, respectively. Resistance and ratio of resistance to height did not differ significantly between the two groups. Reactance and ratio of reactance to height were 21.2% and 20.4% lower in DG than in CG. Phase angle was significantly lower in DG (mean = 4.0; 95% confidence interval [CI], 3.6°-4.3°) than in CG (mean = 4.7; 95% CI, 4.3°-5.1°). Mean fat mass index (6 and 7 kg/m(2)), and mean fat-free mass index (16.4 and 16.6 kg/m(2)) were similar in both groups. BIVA showed a significant downward migration of the ellipse in DG with respect to CG (T(2) = 15.1; P < 0.01). Conventional BIA showed no significant differences in BC between DG and CG, although reactance and ratio of reactance to height were about 21% lower in DG. Nevertheless, a body cell mass depletion and an increase in the ratio of extracellular to intracellular water were identified in DG using BIVA. BIVA reflects dementia-related changes in BC better than BIA.

To determine if there exist differences in the nutritional status of patients with dementia according to the type and severity of the disease. In this cross-sectional study we carried out an assessment of the nutritional status (anthropometrical assessment, Mini Nutritional Assessment, Chang's protocol) in 83 institutionalized elderly diagnosed with dementia at evolutionary states of 5, 6, and 7 of GDS (Global Deterioration Scale) and FAST (Functional Assessment Stating). The results were analyzed by the Chi-squared, ANOVA, or Kruskal-Wallis tests, the Scheffé's posteriori contrasts, and the linear trend test. Significance was considered at p < 0.05. The mean age of the patients was 81.22 years. The BMI revealed that 21% of the sample were at risk for malnourishment and 14.5% were malnourished. However, by using the MNA, 56.6% of the patients were at risk for malnourishment and 41% were malnourished. According to the Chang's method, the percentage of malnourished patients was increased to 75.9%. None of these variables showed an association with the type of dementia. A significant association was observed between the evolutionary state of dementia and the BMI (p = 0.004), MNA (p = 0.002 and p = 0.006 for the score and the category, respectively), the muscle circumference of the arm (p = 0.043) and the calf circumference (p = 0.043) but not with the percentage of fat mass nor the nutritional diagnosis established by the Chang's method (degree and type of MN). The linear trend test confirmed that both the MNA and BMI scores and the muscle circumference of the arm and the calf circumference were lower in the more severe dementia states. Irrespective of the type of dementia, the presence of malnourishment in institutionalized elderly increases in parallel to the evolutionary degree of the dementia.