Body mass index and waist circumference are not good surrogate indicators of adiposity in psychogeriatric patients

Objective to assess the utility of body mass index (BMI) and waist circumference (WC) as surrogate indicators of adiposity with respect to the total body fat estimated with bioimpedance analysis in psychogeriatric patients. Methods Anthropometric and hand-to-foot bioimpedance measurements were performed according to standard procedures in a sample of 128 psychogeriatric patients (87 males, 41 females). WC cutoffs proposed by the International Diabetes Federation were used to define abdominal obesity. Z-scores of fat and fat-free mass indices (Z-FMI and Z-FFMI) were calculated. Results Males with WC values below the cutoff were normal weight, and showed normal levels of FM and low FFM (Z-FFMI below 1.5 SD). Males with WC values above the cutoff were overweight, showed high levels of FM (Z-FMI: 1.34 SD) and a slight depletion of FFM (Z-FFMI: −0.59 SD). In females with WC values below the cutoff, BMI was close to 20 kg/m2 and both FM and FFM were depleted (Z-FMI: −0.7 SD; Z-FFMI: −1.76 SD). In females with WC above the cutoff, the average BMI was 25.6 kg/m2, Z-FMI was 0.48 SD, and Z-FFMI was −0.56 SD. Conclusions Our results indicate that it is necessary to establish age and sex-specific BMI and WC cutoffs, and also highlight the importance of focusing on body composition analysis to ensure an accurate nutritional diagnosis in older-adults and in psychogeriatric patients. Am. J. Hum. Biol., 2015. © 2015 Wiley Periodicals, Inc.