Dataset Information

External validation of the relative fat mass (RFM) index in adults from north-west Mexico using different reference methods.

ABSTRACT: BACKGROUND:Analysis of body composition is becoming increasingly important for the assessment, understanding and monitoring of multiple health issues. The body mass index (BMI) has been questioned as a tool to estimate whole-body fat percentage (FM%). Recently, a simple equation described as relative fat mass (RFM) was proposed by Woolcott & Bergman. This equation estimates FM% using two anthropometric measurements: height and waist circumference (WC). The authors state that due to its simplicity and better performance than BMI, RFM could be used in daily clinical practice as a tool for the evaluation of body composition. The aim of this study was to externally validate the equation of Woolcott & Bergman to estimate FM% among adults from north-west Mexico compared with Dual-energy X-ray absorptiometry (DXA) as an alternative to BMI and secondly, to make the same comparison using air displacement plethysmography (ADP), Bioelectrical Impedance Analysis (BIA) and a 4-compartment model (4C model). METHODS:Weight, height and WC were measured following standard procedures. The RFM index was calculated for each of the 61 participating subjects (29 females and 32 males, ages 20-37 years). The RFM was then regressed against each of the four body composition methods for estimating FM%. RESULTS:Compared with BMI, RFM was a better predictor of FM% determined by each of the body composition methods. In terms of precision the best equation was RFM regressed against DXA (y = 1.12 + 0.99 x; R2 = 0.84 p<0.001). Accuracy (represented by the closeness to the zero-intercept) was 1.12 (95% CI: -2.44, to 4.68) and thus, not significantly different from zero. For the rest of the methods, precision in the prediction of FM% was improved compared to BMI, with significant increases in the R2 and reduction of the root mean squared error (RMSE). However, the intercepts of each regression did not show accuracy since they were different from zero, for ADP: -9.95 (95%CI: -15.7 to -4.14), for BIA: -12.6 (95%CI: -17.5 to -7.74) and for the 4C model: -13.6 (95%CI: -18.6 to -8.60). Irrespectively, FM% measured by each of the body composition methods was higher for DXA than the other three methods (p<0.001). CONCLUSIONS:This external validation proved that the performance of the RFM equation used in this study to estimate FM% was more consistent than BMI in this Mexican population, showing a stronger correlation with DXA than with the other body composition methods.

SUBMITTER: Guzman-Leon AE

PROVIDER: S-EPMC6938316 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

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External validation of the relative fat mass (RFM) index in adults from north-west Mexico using different reference methods.

Guzmán-León Alan E AE Velarde Ana G AG Vidal-Salas Milca M Urquijo-Ruiz Lucía G LG Caraveo-Gutiérrez Luz A LA Valencia Mauro E ME

PloS one 20191231 12

<h4>Background</h4>Analysis of body composition is becoming increasingly important for the assessment, understanding and monitoring of multiple health issues. The body mass index (BMI) has been questioned as a tool to estimate whole-body fat percentage (FM%). Recently, a simple equation described as relative fat mass (RFM) was proposed by Woolcott & Bergman. This equation estimates FM% using two anthropometric measurements: height and waist circumference (WC). The authors state that due to its s ...[more]

PMID: 31891616

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Project description:Abstract Objectives It is imperative to accurately estimate whole body fat percentage (%fat) in order to understand the deleterious nature of excess adiposity on cardiometabolic disease risk. However, cost and accessibility often preclude the use of advanced assessment methods. Relative fat mass (RFM), an emerging estimator of whole body %fat based upon waist circumference, height, and biological sex, has yet to be evaluated in an older adult population. The purpose of this study was to examine the relationship between RFM and gold standard measures of adiposity among older adults, and to evaluate whether changes in RFM reflected changes in %fat following a 12-month lifestyle intervention. Methods This study was ancillary to a randomized controlled trial investigating the effects of a lifestyle intervention with and without intentional energy restriction. (Clinicaltrials.gov #NCT00955903). Older adults with obesity (N = 163, 37.4% male, 70.3 ± 4.7 years) were randomized to one of three groups: exercise only, exercise + nutrient-dense weight maintenance diet, or exercise + nutrient-dense energy restriction of 500 kcal/d. Total and regional adiposity were determined by dual-energy X-ray absorptiometry (DXA) at baseline and 12 months. Data were analyzed using Spearman's correlations, Wilcoxon, Kruskal-Wallis, and linear regression tests. Results At baseline, significant correlations were observed between RFM and DXA whole body %fat (r = 0.751, P < 0.001), DXA total fat (r = 0.353, P < 0.001), and DXA trunk %fat (r = 0.661, P < 0.001). Additionally, RFM was a significant predictor of DXA whole body %fat (P < 0.001) and accounted for 63.5% of model variance. From baseline to 12 months, a significant reduction in RFM was observed among participants in the exercise only and exercise + energy restriction groups (P = 0.020, P < 0.001, respectively). Magnitude of RFM change did not differ among groups. Notably, changes in RFM were significantly correlated with changes in DXA whole body %fat (r = 0.279, P = 0.001) and DXA trunk %fat (r = 0.276, P = 0.001). Conclusions Results support use of RFM as an estimate of whole body %fat, as well as an indicator of its sensitivity to change in fat mass over 12 months in older adults. Incorporation of RFM in cardiometabolic research may provide meaningful information not reflected in conventional body composition measures such as body mass index. Funding Sources NIH

Project description:ObjectivesThe body mass index (BMI) largely underestimates excess body fat, suggesting that the prevalence of obesity could be underestimated. Biologically, women are known to have higher body fat than men. This study aimed to compare the temporal trends in general obesity by sex, ethnicity and age among adults in the USA using the relative fat mass (RFM), a validated surrogate for whole-body fat percentage and BMI.DesignPopulation-based study.SettingUS National Health and Nutrition Examination Survey, from 1999-2000 to 2017-March 2020.ParticipantsA representative sample of adults 20-79 years in the USA.Main outcome measuresAge-adjusted prevalence of general obesity. RFM-defined obesity was diagnosed using validated cut-offs to predict all-cause mortality: RFM≥40% for women and ≥30% for men. BMI-defined obesity was diagnosed using a cut-off of 30 kg/m2.ResultsAnalysis included data from 47 667 adults. Among women, RFM-defined obesity prevalence was 64.7% (95% CI 62.1% to 67.3%) in 2017-2020, a linear increase of 13.9 percentage points (95% CI 9.0% to 18.9%; p<0.001) relative to 1999-2000. In contrast, the prevalence of BMI-defined obesity was 42.2% (95% CI 39.4% to 45.0%) in 2017-2020. Among men, the corresponding RFM-defined obesity prevalence was 45.8% (95% CI 42.0% to 49.7%), a linear increase of 12.0 percentage points (95% CI 6.6% to 17.3%; p<0.001). In contrast, the prevalence of BMI-defined obesity was 42.0 (95% CI 37.8% to 46.3%). The highest prevalence of RFM-defined obesity across years was observed in older adults (60-79 years) and Mexican Americans, in women and men. Conversely, the highest prevalence of BMI-defined obesity across years was observed in middle-age (40-59 years) and older adults, and in African American women.ConclusionsThe use of a surrogate for whole-body fat percentage revealed a much higher prevalence of general obesity in the USA from 1999 to 2020, particularly among women, than that estimated using BMI, and detected a disproportionate higher prevalence of general obesity in older adults and Mexican Americans.

Project description:BACKGROUND:In Ethiopia malaria is one of the top ten leading causes of morbidity and mortality. Community knowledge of prevention and control methods had been proven to play an important role in the implementation of effective and sustainable interventions against malaria. This information is limited in the study area. This study aimed to assess knowledge of malaria prevention and control methods and its associated factors among households in West Belessa district, 2019. METHODS:Community-based cross-sectional mixed quantitative and qualitative study was conducted from April to June 2019 in West Belessa district, North West Ethiopia. Multistage sampling was used to select an estimated 770 sample size. A structured questionnaire was used for the quantitative component and semi-structured questionnaire for the qualitative component. Quantitative data were collected by interviewing and qualitative data using focus group discussion (FGD). Quantitative data was coded and entered using Epi info software version 7 then exported to SPSS version 20 for analysis. The binary logistic regression model was fitted to identify the associated factors. Odds Ratio (OR) with 95% Confidence Interval (CI) was used to assess the strength of association. The qualitative data was transcribed manually using the thematic approach. RESULT:A total of 770 subjects were included in this study with a 99.5% response rate. Of the total respondents, 75.6% had good knowledge of malaria prevention methods. LLINs and IRS were mentioned by 84.7 and 83.7% respectively. Poorest wealth quintiles [AOR?=?0.40, 95% CI: 0.23, 0.73], poor wealth quintiles [AOR?=?0.38, 95% CI: 0.21, 0.70], and medium wealth quintiles [AOR?=?0.41, 95% CI: 0.22, 0.76], living in Menti Kebele [AOR?=?3.07, 95% CI 1.85, 5.08], living in Abay tera kebele [AOR?=?2.00, 95% CI 1.21, 3.29] were significantly associated with good knowledge. About all of the focused group discussion (FGD) participants agreed that malaria is a preventable disease and mentioned some of the preventive methods. CONCLUSION:Overall there was relatively high knowledge of malaria prevention and control methods. LLINs and IRS were known malaria prevention methods in West Belessa. Wealth index and respondents living kebele are predictors for knowledge of malaria prevention.

Project description:BackgroundRecent studies suggest that adjustment of measures of lean mass for adiposity improves associations with physical function. Our objective was to develop and test a method to adjust appendicular lean mass for adiposity.MethodsWhole-body DXA data in 14,850 adults in the National Health and Nutrition Examination Survey were used to generate sex-, and race-specific standard deviation scores (Z-Scores relative to age and T-scores relative to 25 year-olds) for appendicular lean mass index (ALMI, kg/m2) and fat mass index (FMI, kg/m2). Correlations between ALMI and FMI Z- and T-Scores were assessed within demographic categories. Fat-adjusted ALMI (ALMIFMI) scores were determined using residual methods. Sarcopenia was defined as a T-Score <-2.0 and low lean for age as a Z-Score <-1.0. Correlations with physical function were assessed in an at-risk population.ResultsPositive associations between ALMI and FMI Z- and T-Scores were significant (R >0.50; p<0.001) within all demographic categories. The impact of a unit greater FMI Z-score on ALMI Z-score was less in the elderly, men, white subjects, and among individuals with lower FMI (all tests for interaction p<0.001). There was fair agreement between ALMI and ALMIFMI estimates of sarcopenia and low lean for age [Kappa: 0.46, 0.52, respectively (p<0.0001)]. Elderly subjects were likely to be re-classified as sarcopenic while young subjects were likely to be re-classified as normal using ALMIFMI. ALMIFMI T-scores resulted in approximately twice the number of subjects defined as sarcopenic, compared with ALMI T-Scores. (1299 v. 534). Among rheumatoid arthritis patients, ALMIFMI Z-scores correlated with physical function (Health Assessment Questionnaire: rho = -0.22, p = 0.04; Short Physical Performance Battery: rho = 0.27, p = 0.01); however, the ALMI Z-Score did not.ConclusionsAdjustment of ALMI for the confounding association with FMI impacts the definition of lean mass deficits. These methods provide a practical tool for investigators and clinicians based on population-based reference data.

Project description:BackgroundAlthough there has been momentum in implementing sexual and reproductive health services in Ethiopia, young people remain underserved despite their demonstrated needs. Quality care improves utilization of health service and increases the likelihood of obtaining ongoing care. However, little is known about the quality of youth-friendly sexual and reproductive health service in Ethiopia. Therefore, this study sought to investigate the quality of youth-friendly sexual and reproductive health service in West Gojjam Zone, North West Ethiopia.MethodsHealth facility-based cross-sectional study was conducted in West Gojjam zone in 2018 to assess the quality of the service using the Donabedian model. The assessment was done through the triangulation of multiple methods: simulated client study; structured interviews with service providers; observations; and key informant interview with providers and expertise. Fifty-four visits were made to 18 randomly selected health facilities by three simulated clients trained to present three different scenarios (i.e., adolescent with sexually transmitted infection, pregnancy test request and a lady with dry cough). Data were entered and analyzed using SPSS version 21. Facility visit score of ≥ 75% in all quality component categorized as "good quality" otherwise classified as performing below the standard. Thematic analysis was done to analyze qualitative data.ResultsIn this study, none of the health facilities achieved ≥ 75% in the three components of quality measurement. From 18 health facilities, 6(33.3%) provided low quality in all domains. Process component, which measures client-provider interaction and privacy/confidentiality, was the most compromised one. However, a promising result was reported in the input quality that measured the availability of trained providers, drugs, and supplies. The presence of community-based health insurance and age driven comprehensive youth-friendly service delivery approach were identified as challenges to deliver quality services.ConclusionsThe quality of the service ranges from low to medium, with adolescent related elements performing poorly. Minor renovations of health facilities, training on client handling, and contextual modifying the age driven youth-friendly service approach may improve the quality of the services.

Dataset Information

External validation of the relative fat mass (RFM) index in adults from north-west Mexico using different reference methods.

Publications

External validation of the relative fat mass (RFM) index in adults from north-west Mexico using different reference methods.

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