Comparison between resting metabolic rate and indirect calorimetry in postmenopausal women

https://doi.org/10.1590/1678-98652017000500004 581 ORIGINAL ORIGINAL RESTING METABOLIC RATE IN POSTMENOPAUSE Comparison between resting metabolic rate and indirect calorimetry in postmenopausal women Comparação de equações preditivas de taxa metabólica de repouso com calorimetria indireta em mulheres pós-menopáusicas Randhall Bruce CARTERI1,2 Marceli FELDMANN2 Júlia Silveira GROSS2 Renata Lopes KRUGER2 André Luis LOPES2 Álvaro REISCHAK-OLIVEIRA2 ABSTRACT Objective To compare resting metabolic rate values determined by indirect calorimetry with values estimated using different predictive equations in lean and overweight postmenopausal women. Methods Twenty-four women, who had stopped menstruating for at least two years, were subjected to anthropometric measurements and indirect calorimetry after 12-hour overnight fasting to determine, mathematically and experimentally, resting metabolic rate values. Results There was no difference in the indirect calorimetry values between the groups evaluated. Difference values of resting metabolic rate were obtained with all equations used. For the lean women, there was no difference between the values obtained by indirect calorimetry and those estimated using the equations proposed by Food and Agricultural Organization, Fredix, Lazzer, and Schofield. However, in the overweight group, the resting metabolic rate values estimated using the Institute of Medicine, Berstein and Owen equations were different from those obtained by indirect calorimetry. 1 Universidade Federal do Rio Grande do Sul, Instituto de Ciências Básicas da Saúde, Departamento de Bioquímica. R. Ramiro Barcelos, 2600, 90035-003, Porto Alegre, RS, Brasil. Correspondência para/Correspondence to: RB CARTERI. E-mail: <>. 2 Universidade Federal do Rio Grande do Sul, Escola de Educação Física, Laboratório de Pesquisa do Exercício. Porto Alegre, RS, Brasil. Rev. Nutri., Campinas, 30(5):583-591, set./out., 2017 Revista de Nutrição 582 RB CARTERI et al. https://doi.org/10.1590/1678-98652017000500004 Conclusion This study suggests that differences in body composition in postmenopausal women influence the accuracy of predictive equations, demonstrating the need for more accurate estimation methods for resting metabolic rate in postmenopausal women with different body compositions. Keywords: Basal metabolism. Calorimetry indirect. Menopause. RESUMO Objetivo Comparar os valores de taxa metabólica de repouso determinados por calorimetria indireta com os valores obtidos utilizando diferentes equações preditivas em mulheres pós-menopausicas eutróficas e com sobrepeso. Métodos Vinte e quatro mulheres com pelo menos dois anos de menopausa foram submetidas à avaliações antropométricas e à calorimetria indireta após 12 horas de jejum para determinar, matematicamente e experimentalmente, a taxa metabólica de repouso. Resultados Os valores para calorimetria indireta não diferiram entre os grupos e a taxa metabólica de repouso predita por equações foi diferente para todas as equações usadas. Para o grupo de eutróficas, as equações que não foram estatisticamente diferentes da calorimetria indireta foram Food and Agricultural Organization, Fredix, Lazzer e Schofield. No entanto, apenas as equações Berstein e Owen foram significativamente diferentes comparadas com calorimetria indireta para o grupo sobrepeso. Conclusão O presente estudo sugere que diferenças na composição corporal em mulheres na pós-menopausa modificam a precisão de equações que predizem a taxa metabólica de repouso, demonstrando a necessidade de aprimorar métodos de estimação de taxa metabólica de repouso em mulheres pós-menopáusicas com diferentes composições corporais. Palavras-chave: Metabolismo basal. Calorimetria indireta. Menopausa. INTRODUCTION Menopause progression leads to several changes in the hormonal profile, which exert impact on parameters related to Resting Metabolic Rate (RMR) and body composition, such as increased adipose tissue, increased central adiposity, and decreased lean mass, consequently increasing the risk of developing metabolic and cardiovascular diseases [1,2]. Thus, interventions based on the individual estimates of the energy requirements in terms of diet and exercise to determine an adequate energy balance should be recommended for health promotion in postmenopausal women [3]. Resting metabolic rate can be obtained by indirect calorimetry or predicted by different equations. Indirect calorimetry is a method by Revista de Nutrição which metabolic rate is measured based on the oxygen consumption (O2) and the production of carbon dioxide (CO2), considering that the total O2 consumed is related to the oxidation of macronutrients and the total CO2 produced is detected during the test, allowing individual RMR measurement [4]. Although it is a reliable measurement method, indirect calorimetry is expensive, time consuming, and requires trained personnel to perform it [4]. For these reasons and due to their feasibility and low cost, predictive equations are widely used in clinical practice [5]. However, there is only one equation based on postmenopausal women characteristics [6]; most equations are based on studies that describe lean individuals and a broad age group [7]. Noteworthy, most of the existing equations are outdated and may Rev. Nutri., Campinas, 30(5):583-591, set./out., 2017 https://doi.org/10.1590/1678-98652017000500004 not be compatible with the general population, considering that there has been an exponential increase in sedentary lifestyle and obesity, resulting in differences in body composition, which leads to changes in energetic demand [8]. Predictive equations generally consider patients’ anthropometric variables such as weight, height, and age. Several studies report that when used for individuals with different levels of obesity, these equations usually overestimate RMR [9,10]. Recent literature investigating the applicability and reliability of the most commonly used equations, such as Harris-Benedict, Schofield, Food and Agriculture Organization of the United Nations (FAO), and Mifflin-St. Jeor, present conflicting results in different populations [11-14]. Studies evaluating elderly individuals often report an overestimation of RMR [11]. Therefore, this research is justified by the lack of studies involving postmenopausal women, the inclusion of less commonly used equations, and the conflicting available data on the efficacy and effectiveness of predictive equations when compared to more precise methods, such as indirect calorimetry, due to their importance since they are practical and inexpensive methods for clinical application. Thus, the objective of the present study was to compare RMR values determined by indirect calorimetry to those obtained using different predictive equations in lean and obese postmenopausal women. METHODS Twenty-four postmenopausal women, who volunteered after seeing advertisements in local newspapers, participated in the study (...truncated)