Body fat measurement by bioelectrical impedance and air displacement plethysmography: a cross-validation study to design bioelectrical impedance equations in Mexican adults

<p>Abstract</p> <p>Background</p> <p>The study of body composition in specific populations by techniques such as bio-impedance analysis (BIA) requires validation based on standard reference methods. The aim of this study was to develop and cross-validate a predictive equation for bioelectrical impedance using air displacement plethysmography (ADP) as standard method to measure body composition in Mexican adult men and women.</p> <p>Methods</p> <p>This study included 155 male and female subjects from northern Mexico, 20–50 years of age, from low, middle, and upper income levels. Body composition was measured by ADP. Body weight (BW, kg) and height (Ht, cm) were obtained by standard anthropometric techniques. Resistance, R (ohms) and reactance, Xc (ohms) were also measured. A random-split method was used to obtain two samples: one was used to derive the equation by the "all possible regressions" procedure and was cross-validated in the other sample to test predicted versus measured values of fat-free mass (FFM).</p> <p>Results and Discussion</p> <p>The final model was: FFM (kg) = 0.7374 * (Ht²/R) + 0.1763 * (BW) - 0.1773 * (Age) + 0.1198 * (Xc) - 2.4658. R²was 0.97; the square root of the mean square error (SRMSE) was 1.99 kg, and the pure error (PE) was 2.96. There was no difference between FFM predicted by the new equation (48.57 ± 10.9 kg) and that measured by ADP (48.43 ± 11.3 kg). The new equation did not differ from the line of identity, had a high R²and a low SRMSE, and showed no significant bias (0.87 ± 2.84 kg).</p> <p>Conclusion</p> <p>The new bioelectrical impedance equation based on the two-compartment model (2C) was accurate, precise, and free of bias. This equation can be used to assess body composition and nutritional status in populations similar in anthropometric and physical characteristics to this sample.</p

Greater male variability in daily energy expenditure develops through puberty

The authors also gratefully acknowledge funding from the Chinese Academy of Sciences (grant no. CAS153E11KYSB20190045) to J.R.S. and the US National Science Foundation (grant no. BCS-1824466) awarded to H.P. Acknowledgements Yvonne Schönbeck provided important information about morphometric measurements for Dutch children. A chat over dinner with Karsten Koehler, Eimear Dolan and Danny Longman brought up a number of thoughts that influenced this manuscript. The DLW database, which can be found at https://doublylabelled-waterdatabase.iaea.org/home, is hosted by the IAEA and generously supported by Taiyo Nippon Sanso and SERCON. We are grateful to the IAEA and these companies for their support and especially to Takashi Oono for his tremendous efforts at fundraising on our behalf.Peer reviewedPublisher PD

Greater male variability in daily energy expenditure develops through puberty

There is considerably greater variation in metabolic rates between men than between women, in terms of basal, activity and total (daily) energy expenditure (EE). One possible explanation is that EE is associated with male sexual characteristics (which are known to vary more than other traits) such as musculature and athletic capacity. Such traits might be predicted to be most prominent during periods of adolescence and young adulthood, when sexual behaviour develops and peaks. We tested this hypothesis on a large dataset by comparing the amount of male variation and female variation in total EE, activity EE and basal EE, at different life stages, along with several morphological traits: height, fat free mass and fat mass. Total EE, and to some degree also activity EE, exhibit considerable greater male variation (GMV) in young adults, and then a decrease in the degree of GMV in progressively older individuals. Arguably, basal EE, and also morphometrics, do not exhibit this pattern. These findings suggest that single male sexual characteristics may not exhibit peak GMV in young adulthood, however total and perhaps also activity EE, associated with many morphological and physiological traits combined, do exhibit GMV most prominently during the reproductive life stages

Greater male variability in daily energy expenditure develops through puberty

There is considerably greater variation in metabolic rates between men than between women, in terms of basal, activity and total (daily) energy expenditure (EE). One possible explanation is that EE is associated with male sexual characteristics (which are known to vary more than other traits) such as musculature and athletic capacity. Such traits might be predicted to be most prominent during periods of adolescence and young adulthood, when sexual behaviour develops and peaks. We tested this hypothesis on a large dataset by comparing the amount of male variation and female variation in total EE, activity EE and basal EE, at different life stages, along with several morphological traits: height, fat free mass and fat mass. Total EE, and to some degree also activity EE, exhibit considerable greater male variation (GMV) in young adults, and then a decrease in the degree of GMV in progressively older individuals. Arguably, basal EE, and also morphometrics, do not exhibit this pattern. These findings suggest that single male sexual characteristics may not exhibit peak GMV in young adulthood, however total and perhaps also activity EE, associated with many morphological and physiological traits combined, do exhibit GMV most prominently during the reproductive life stages

Prevalence of metabolic syndrome and its determinants in older Mexican non-diabetic adults

Abstract Introduction: the prevalence of metabolic syndrome (MetS) is high in older people, and several factors have been explored as main determinants. However, few data exist for older people from low- and middle-income countries. Therefore, our objective was to estimate the prevalence of MetS. Secondly, to explore which of the cardio-metabolic, body composition, inflammatory and demographic risk factors were associated with the prevalence of MetS in a population of older Mexican adults. Methods: data for this analysis were collected in subjects over 60 years of age from northwest Mexico. Fasting and two-hour glucose, fasting insulin, homeostasis model assessment of insulin resistance, lipid profiles, markers of adiposity and inflammation, and blood pressure were assessed. In addition, anthropometry and body composition data, levels of physical activity and demographic variables were also considered. MetS was diagnosed by three different criteria. Results: total sample size was 369 subjects. The prevalence of MetS varied widely, from 36% to 52% depending on the criteria applied, but regardless of the criteria, all subjects with MetS were heavier and more overweight, and had higher triglyceride values and lower values of total HDL-cholesterol compared to those without MetS (p < 0.0001). Final models adjusted for age showed that, regardless of the diagnostic criteria applied, fat mass, the homeostasis model assessment and some demographic variables were main determinants of MetS in this sample of older people without diabetes. Conclusions: the prevalence of MetS is relatively high in non-diabetic older adults and it was associated with some biological and demographic factors as the main determinats

Antropometría y composición corporal en personas mayores de 60 años. Importancia de la actividad física Anthropometry and body composition in elderly people. Importance of physical activity

OBJETIVO. Medir los indicadores antropométricos de composición corporal por bioimpedancia eléctrica y la actividad física, así como la glucosa sanguínea y la presión arterial en personas mayores de 60 años de una región rural. MATERIAL Y MÉTODOS. Por muestreo intencional no probabilístico se seleccionaron 54 sujetos mayores de 60 años, quienes se sometieron al protocolo estandarizado para las mediciones antropométricas y composición corporal por bioimpedancia eléctrica (BIE) y actividad física mediante el cuestionario de actividades. Asimismo, se midió la presión arterial y se realizó la prueba de tolerancia a la glucosa. Los valores promedio se analizaron por sexo mediante la prueba t de Student, y la asociación de la actividad física y la composición corporal con otras variables, por regresión lineal simple y el coeficiente de correlación de Pearson. RESULTADOS. La actividad física correlacionó negativamente con el porcentaje de grasa (r= -0.36; p= 0.007); la presión arterial diastólica (r= -0.36; p= 0.006) y sistólica (r= -0.32; p= 0.018) y el índice de masa corporal, con la glucosa posdosis (r= 0.31; p= 0.024). CONCLUSIONES. La actividad física en este grupo de personas puede tener un impacto favorable respecto a los indicadores de salud tan importantes que se mencionaron.<br>OBJECTIVE. To measure anthropometric indicators of body composition by electric bioimpedence, as well as physical activity, blood glucose and arterial pressure in rural people over 60 years of age. MATERIAL AND METHODS. A total of 54 subjects over 60 years old were selected by intentional non-probabilistic sampling. They were subjected to a standardized protocol to measure anthropometric indicators, body composition by electric bioimpedance (EBI), and physical activity was determined by an activity questionnaire. Arterial pressure and glucose tolerance levels were also measured. Analysis included Student's t test to detect differences by sex and the association of physical activity, body composition and other variables by simple linear regression and Pearson's correlation coefficient. RESULTS. Physical activity correlated negatively with percent fat (r= -0.36; p= 0.007) and diastolic (r= -0.36; p= 0.006) and systolic blood pressure (r= -0.32; p= 0.018), and body mass index with post dose glucose (r= 0.31; p= 0.024). CONCLUSIONS. Physical activity in this age group may have a favorable impact with respect to the mentioned health indicators

Effect of overweight and obesity on the equilibrium time, but no in the total body water and body composition compartments in women subjects over 60 years of age

Artículo de publicación ISIIntroduction: aging and obesity cause changes in water exchange rate, which could affect the equilibrium time of deuterium oxide (21120). Objective: to assess the effect of overweight and obesity on the equilibrium time of the stable isotope deuterium in saliva samples of older adults. Methods: a sample of 18 women over 63 years with a body mass index (BMI) of 20.8 to 40.5 kg/m(2) were included. A basal saliva sample was took and immediately a dose of 30 g of (H2O)-H-2 was administered orally. Saliva samples at 2, 2.5, 3, 3.5 and 4 hours post-dose were taken. Deuterium in saliva samples were analyzed by Fourier Transform Infrared spectroscopy technique. Results: the average in equilibrium time (plateau) in women of normal BMI (18.5-24.9 kg/m(2)) was 3.6 +/- 0.2 hours, which was statistically different to those obtained in the group with overweight (25-29.9 kg/m(2)) and obese (>30 kg/m(2)) of 2.9 +/- 0.4 hours and 2.8 +/- 0.4 hours, respectively (p0.05). Conclusion: obesity had an effect on the equilibrium times; however, did not affect the calculation of total body water and body composition in this older women adult group.Introducción: el envejecimiento y la obesidad producen cambios en la tasa de recambio de agua, lo que podría afectar al tiempo de equilibrio del óxido de deuterio (2 H2 O). Objetivo: se evaluó el efecto del sobrepeso y la obesidad sobre el tiempo de equilibrio del isótopo estable de deuterio en muestras de saliva de adultos mayores. Métodos: se incluyeron 18 mujeres entre 63 y 80 años con un índice de masa corporal (IMC) de 20,8 a 40,5 kg/m2 . Después de la toma de una muestra de saliva basal se administró una dosis vía oral de 30 g de 2 H2 O. Se tomaron muestras de saliva a las 2, 2,5, 3, 3,5 y 4 horas post-dosis, las cuales fueron analizadas mediante espectrometría infrarroja con transformada de Fourier. Resultados: el tiempo de equilibrio (plateau) promedio en las mujeres con un IMC normal (18,5-24,9 kg/m2 ) fue de 3,6 ± 0,2 horas, el cual fue diferente estadísticamente al obtenido en el grupo con sobrepeso (25-29,9 kg/m2 ) y obesidad (>30 kg/m2 ) de 2,9 ± 0,4 horas y 2,8 ± 0,4 horas, respectivamente (p<0,05). Los valores de agua corporal total y la masa corporal libre de grasa calculados con los valores de enriquecimiento isotópico a las 3,6 (plateau alcanzado en el grupo con IMC normal) no fueron diferentes estadísticamente a los valores calculados al plateau a las 2,9 y 2,8 horas en el grupo con sobrepeso y obesidad, respectivamente (p>0,05). Conclusión: se encontró un efecto de la obesidad sobre el tiempo de equilibrio; sin embargo, no afectó al cálculo del agua corporal total y a la composición corporal en este grupo etario