Assessing nutritional status in the elderly; Evaluation of Chumlea's equations for weight

Background: Weight is one of the most important parameters in assessing nutritional status. However, weight can be difficult to measure in elderly people who are unable to stand. Chumlea et al. created two equations to estimate weight in non-ambulatory patients using readily available body measurements. Objective: The aim of the study is to analyze the usefulness of Chumlea's equations in assessing nutritional status of elderly hospitalized patients. Methods: We measured weight, height, arm and calf circumference, subscapular skinfold and knee height of 82 hospitalized elderly patients, all of whom were able to stand. Estimated weight (EW) was obtained by Chumlea's equations. Body mass index (BMI) and Mini Nutritional Assessment test (MNA) were calculated using actual weight and EW. Bland-Altmann analysis and intraclass correlation coefficient (ICC) between real and estimated parameters were assessed. Results: We found a statistically significant ICC between actual weight and EW (r = 0.926), real BMI and estimated BMI (r = 0.910) and real MNA and estimated MNA (r = 0.982) (P < 0.001). Chumlea's equations, however, underestimated weight: 54.05 (DS 11.88) vs 61.46 (DS 13.08); BMI: 22.30 (DS 4.61) vs 25.36 (DS 5.17) and MNA: 22.73 (DS 4.43) vs 23.30 (DS 4.33) (P<0.001). In spite of this underestimation, estimated MNA detected 100% of patients malnourished and 96% of those at risk of malnutrition. Conclusions: Results obtained by Chumlea's equations showed a good ICC with actual body weight and real BMI and MNA, but values were underestimated. These equations can be useful to detect undernourished hospitalized elderly patients.