Reliability Of Body Mass Index Research Articles

Comparing the validity of anthropometric measurements in identifying malnutrition status of older age people in Borena district, North Central Ethiopia: a cross_sectional study

BackgroundMalnutrition among older age people is becoming significantly higher in spite of improvements in the health care system. Life expectancy of Ethiopian elders is increasing; but reliable and valid tools for screening and diagnosis of malnutrition in this subgroup are limited. This study aimed to assess the validity of anthropometric measurements: Mid Upper Arm Circumference (MUAC), Body Mass Index (BMI), and Calf Circumference (CC) in detecting malnutrition status of older age people in Ethiopia.MethodsA community based cross-sectional study was conducted in Borena District from January to March, 2020. A total of 421 participants aged were systematically included in the study. To test reliability and validity of the measurements,Cronbach’s α coefficient and Pearson’s correlations were used, respectively. The full Mini-Nutritional Assessment (MNA) tool was used to diagnosis malnutrition. Overall accuracy, sensitivity and specificity of BMI, MUAC and CC were estimated using Receiver Operating Characteristic curves. The Youden Index was used to determine the best cut-off point.ResultsThe reliability of BMI, MUAC and CC by Cronbach’s alpha was found 0.847. Significant positive correlations between MNA, BMI(r = 0.56, p < 0.01); MNA, MUAC(r = 0.43, p < 0.01; and MNA, CC(r = 0.52, p < 0.01) revealed. The area under the curve (AUC) of BMI, MUAC and CC were found: 0.98(95% CI, 0.96–0.99, p < 0.001), 0.94(95% CI, 0.89–0.98, p < 0.001) and 0.96(95% CI, 0.94–0.98, p < 0.001) indicating the overall accuracy respectively. The sensitivity and specificity of BMI, MUAC and CC using established cut off points were found: 90%, 96%; 78%, 94% and 84%, 95% respectively. However, using the Youden index the best cut-off point, the sensitivity and specificity of MUAC and CC were 88%, 86%; 92% and 89% respectively and adjusted for age and sex.ConclusionsThe current study demonstrated that BMI was a reliable and valid method to identify the malnutrition status of older age people. A MUAC value of 19 cm and CC of 30 cm were simple and efficient cut-off points for the determination of malnutrition in the older age people. A future study is needed to validate the validity of BMI, MUAC and CC against biochemical tests as gold standard.

Predictive Ability of Seven Anthropometric Indices for Cardiovascular Risk Markers and Metabolic Syndrome in Adolescents

PurposeThe aim of the study was to evaluate the reliability of 7 anthropometric indices in predicting cardiovascular risk markers (CRMs) and metabolic syndrome (MetS) in Brazilian adolescents. MethodsA cross-sectional study conducted with 1,069 participants of the Cardiovascular Risk in Adolescents Study aged 12–17 years. Receiver operating characteristics curves were plotted, and area under curve (AUC) was calculated for body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHR), conicity index (CoI), body shape index (BSI), adjusted BSI for adolescents (adjusted BSI), and body roundness index (BRI). ResultsIn girls, reliability of BMI, WC, WHR, and BRI was sufficient (≥.6 AUC <.7) only to predict high blood pressure. Among boys, reliability of BMI, WC, WHR, BRI, and adjusted BSI ranged from good to sufficient (≥6 AUC <.8) to predict insulin resistance and high blood pressure, but poor to sufficient (≥.5 AUC <.7) for high total cholesterol, triglycerides, and low-density lipoprotein. For both sexes, CoI and BSI presented AUC ≤.5 for all CRM. A majority of the anthropometric indices showed AUC ≥.9 for MetS. ConclusionReliability of CoI, BSI, adjusted BSI, and BRI is not superior to BMI, WC, and WHR in predicting CRM and MetS. All the anthropometric indices had excellent predictive capacity for MetS, but limited accuracy for CRM. Among the evaluated indices, we recommend the use of cutoff point WHR ≥.55 to screening MetS in girls and boys because of its easy to measure and interpretation.

The reliability of body mass index in the diagnosis of obesity and metabolic risk in children.

Body mass index (BMI) is the most widespread and the simplest method for the evaluation of body mass; it is often used as a sole technique in the diagnosis of obesity in children. The objective of the study was to evaluate the relationship between anthropometric and biochemical parameters and the incidence of the metabolic syndrome in obese children. A total of 110 children, aged 2-17 years, participated in the study. No overweight children (BMI 85-95 percentiles) were included. BMI was interpreted using the 2000 Centers for Disease Control and Prevention Growth Charts. The skinfold measurements were performed using an John Bull British Indicators Ltd. calipers, and interpreted using an the reference table values. In addition to lower sensitivity (mentioned in several earlier studies), BMI also shows a lower specificity in the diagnosis of obesity in children: BMI showed at least 10% of non-concomitance with skinfold thickness and waist circumferences and 8% with waist-to-height ratio. In addition, subscapular skinfold thickness, waist circumference, and waist/height ratio showed stronger correlations with serum insulin levels, low-density lipoprotein cholesterol, and family history than BMI itself. The unreliability of BMI as the sole parameter for diagnosing obesity in children was found in our study. Even when overweight children were excluded from the study, the lack of specificity of BMI was demonstrated. We propose utilization of waist circumference and waist/height ratio along with the BMI for definitive diagnosis instead of relying on BMI only. In addition, waist circumference and subscapular fold thickness may be even better in estimation of metabolic risk than BMI.

Is air-displacement plethysmography a reliable method of detecting ongoing changes in percent body fat within obese children involved in a weight management program?

The prevalence of childhood obesity in the US has increased considerably over the last few decades and continues to increase. To monitor the progress of patients enrolled in weight management programs, clinicians need accurate methods of detecting changes in body composition (percent body fat) over time. The gold standard method, hydrodensitometry, has severe limitations for the pediatric population. This study examines the reliability of air-displacement plethysmography (ADP) in detecting percent body fat changes within obese children over time. Percent body fat by ADP, weight, and body mass index (BMI) were measured for eight obese children aged 5-12 years enrolled in a weight management program over a 12-month period. These measurements were taken at initial evaluation, 1.5 months, 3 months, 6 months, and 12 months to monitor the progress of the subjects and detect any changes in these measures over time. Statistical analysis was used to determine the reliability of the data collected. The reliability estimate for percent body fat by ADP was 0.78. This was much lower than the reliability of BMI, 0.98, and weight measurements, 0.99. The low reliability estimate of ADP indicates a large standard error of measurement by this method. The measurement error of ADP is large, and in our study, ADP measured changes in percent body fat that far exceeded levels of true change that would have been clinically useful and important to detect. Hence, this method yielded change measures that did not allow meaningful clinical interpretations and often did not reflect true differences in status across time. ADP is not a reliable method for detecting changes in percent body fat over the time intervals employed within this study of obese children.

Validity of currently used cutoff values of body mass index as a measure of obesity in Sri Lankan children

The aim of the study was to determine the reliability of body mass index based (BMI) cutoff values in diagnosing obesity among Sri Lankan children. Height, weight, waist circumference (WC) and hip circumference (HC) in 282 children were measured. Total body water was determined by deuterium dilution and fat mass (FM) derived using age and gender specific constants. A percentage FM of 30% for girls and 25% for boys were considered as cutoff levels for obesity. Two hundred and eighty two children (M/F: 158/124) were studied and 99 (80%) girls and 72 (45.5%) boys were obese based on % body fat. Eight (6.4%) girls and nine (5.7%) boys were obese based on International Obesity Task Force (IOTF) cutoff values. Percentage FM and WC centile charts were able to diagnose a significant proportion of children as true obese children. The FM and BMI were closely associated in both girls (r = 0.82, p < 0.001) and boys (r = 0.87, p < 0.001). Percentage FM and BMI had a very low but significant association; girls (r = 0.32, p < 0.001) and boys (r = 0.68, p < 0.001). FM had a significant association with WC and HC. BMI based cutoff values had a specificity of 100% but a very low sensitivity, varying between 8% and 23.6%. BMI is a poor indicator of the percentage fat and the commonly used cutoff values were not sensitive to detect cases of childhood obesity in Sri Lankan children.

Misclassification of Body Mass Index (BMI) using self-reported weight and height in an urban Mexican-American population

To assess the impact of differential misclassification of BMI category on resultant data analysis and interpretation when using self-reported weight and height versus measured weight and height. In an ongoing cohort study of Mexicans and Mexican-Americans in Houston, Texas, we evaluated the reliability of Body Mass Index (BMI) calculated from self-reported to measured weight and height among a sample of 955 adults, aged 20–93. Spearman correlations were calculated for height, weight and BMI. We examined the mean differences between measured and self-reported values using Student's t-tests. The mean difference, calculated as BMI from measured weight and height − BMI from self-reported weight and height, was 0.79 units for women (p < 0.0001) and 0.42 units for men (p = 0.0141). Spearman correlations were calculated for height (0.81 in men and 0.70 in women), weight (0.92 in men and 0.95 in women), and BMI (0.85 in men and 0.88 in women). We evaluated the potential for BMI misclassification based on the 1998 NHLBI categories (Underweight <18.5, Normal 18.5 – 24.9, Overweight 25.0 – 29.9, Obesity I 30.0 – 34.9, Obesity II 35.0 – 39.9, Extreme Obesity ≥ 40). We found that even small inaccuracies in self-reported weight (1–2 lbs.), and height (<1 inch), lead to 33% of participants being misclassified. Using measured values as gold standard, 11% were misclassified to a higher BMI category and 22% to a lower category. The BMI misclassification was differential by gender. BMI from self-reported data was overestimated by one or more categories by 16% of men and 12% of women and underestimated by 14% of men and 21% of women. This differential misclassification seems to be primarily due to both men and women overestimating their height and women underestimating their weight. These findings suggest the need for caution when using self-reported data to calculate BMI among adults, and underscore the need for similar studies in other populations.