Systematic Review of Equations for Estimating Energy Requirement in the Elderly: Results and Future Perspectives

Abstract

Abstract Objectives Estimating the right energy requirement for the elderly is a clinically relevant topic since malnutrition is common in such population. Predictive equations are widely used to estimate the resting energy expenditure (REE). However, only a few equations have been specifically developed for the elderly, and they often provide different outputs. The present work aimed at presenting a web application able to assist the clinicians in identifying the most appropriate equation to estimate the REE in the elderly. Methods The development of the application is based on a systematic review of studies that had tested the performance of a predictive equation to estimate REE vs. a gold standard in subjects older than 65 years of age. The systematic review was carried out using PubMed, Scopus, and Embase following the PRISMA guidelines. Furthermore, the equations retrieved were applied to a sample of 88 subjects enrolled in an Italian nursing home to evaluate the agreement among the estimated REE. The agreement was assessed using the Intraclass Correlation Coefficient (ICC) for the sample overall and for specific subsets of patients (males, females, normal-weight and overweight/obese subjects). Results The initial search identified 6353 studies. After the screening, 69 studies, corresponding to 210 single equations, were included in the analysis. The type and number of parameters used in each equation were highly variable and the most frequently used were demographics, anthropometric and laboratory data, and physical activity frequency. The application of the equations to the sample of 88 subjects enrolled in the nursing home showed that the ones that included a small number of parameters were found to have a good agreement (especially those including the body weight alone: ICC = 0.75, 95% IC 0.69–0.81) while the addition of other parameters resulted in a worsening of the agreement. The same results were obtained for the sample overall and for the specific subsets of patients considered. The results of the systematic review served as a basis for the development of the web application (http://r-ubesp.dctv.unipd.it:3838/equationer). Conclusions The proposed web application is expected to guide the clinicians in identifying the most appropriate equation to estimate REE according to the subject's characteristics. Funding Sources University of Padova.