Diagnostic Accuracy of Body Mass Index in Defining Childhood Obesity: Analysis of Cross-Sectional Data from Ghanaian Children

MULT: An allometric body mass index (ABMI) reference to assess nutritional status of multiethnic children and adolescents

OBJECTIVES

To develop an allometric body mass index (ABMI) reference that adjusts the weight in relation to height, taking into account the changes during development (MULT ABMI reference), and to compare it with international BMI references.

METHODS

The MULT ABMI reference was constructed through the LMS method, calculated with 65 644 ABMI observations of 17 447 subjects aged 5-22 years, from the United Kingdom, Ethiopia, India, Peru, Vietnam, Portugal, and Brazil. The M, S, and L curves of the MULT ABMI reference were compared with the curves of the MULT, World Health Organization (WHO), Centers for Disease Control and Prevention (CDC), International Obesity Task Force (IOTF), and Dutch Growth Study (DUTCH).

RESULTS

The greater differences in the M curve between MULT ABMI and WHO, CDC, IOTF, DUTCH, and MULT BMI references were around puberty (138 to 150 months for boys; 114 to 132 for girls). MULT ABMI presented S values similar to IOTF and DUTCH BMI references for boys 60 to 114 months and then became higher, approaching the MULT BMI S values from 198 to 240 months. For girls the MULT ABMI S values were close to the IOTF, CDC, and DUTCH from 60 to 110 months, and then became higher, approaching the MULT BMI S values until 240 months.

CONCLUSION

MULT ABMI presented an advantage in comparison to the existing BMI references because it takes into account the growth changes during puberty and is a new option to assess the nutritional status of multiethnic populations.

MULT: A new BMI reference to assess nutritional status of multi-ethnic children and adolescents

OBJECTIVES

To develop a new Body Mass Index (BMI) reference (MULT) based on longitudinal data of multi-ethnic populations and to compare it to international BMI references.

METHODS

The MULT BMI reference was constructed through the LMS method and the Generalized Additive Models for Location Scale and Shape (GAMLSS), with 81 310 observations of 17 505 subjects aged 0-22 years old, from the United Kingdom, Ethiopia, Peru, India, Vietnam, Brazil, and Portugal. Outlier values were removed based on weight z-scores (population level) and based on BMI z-scores using the linear mixed effects model (individual level). The MULT M, S and L curves were compared to the ones of the World Health Organization (WHO), Centers for Disease Control and Prevention (CDC), International Obesity Task Force (IOTF), and Dutch Growth Study (DUTCH). The MULT BMI percentile cutoffs for overweight and obesity were calculated using the adult BMI values of 25 and 30 kg/m2 at 17, 18, 19, and 20 years old.

RESULTS

MULT presented the lowest mean BMI values for the ages 102-240 months for boys and 114-220 months for girls. MULT S values were similar to the WHO and IOTF for children under 60 months of age and the highest during puberty, while the L curve showed to be more symmetric than the other BMI references.

CONCLUSION

The MULT BMI reference was constructed based on recent data of populations from 10 countries, being a good option to assess the nutritional status of multi-ethnic populations.

Accelerating the healing of hard-to-heal wounds with food supplements: nutritional analysis in the Côte d'Ivoire

OBJECTIVE

Hard-to-heal wounds are an important, yet often neglected, public health issue in low- and middle-income countries (LMICs). Malnutrition has been identified as a risk factor for prolonged healing times. However, nutritional supplements are not routinely provided for patients with hard-to-heal wounds, and so this study aimed to investigate their benefits.

METHOD

This 9-month study was conducted in the Taabo Health and Demographic Surveillance System in the south-central part of Côte d'Ivoire. Patients with wounds (≥30mm2) were recruited. Treatment was standardised for inpatients (72%) and outpatients (28%). There were three intervention groups: supplemented with soy; orange flesh sweet potato (OFSP); or both. Another group was included without supplement, serving as control. General linear models were employed to assess the effects of log initial wound size, type of wound, food treatment group, haemoglobin, sex, age, place of treatment and body mass index on the rate of wound closure.

RESULTS

The cohort consisted of 56 patients, 41 of whom were placed in intervention groups, and the remainder as controls. Within the cohort, 37 (66%) patients suffered from Buruli ulcer, 15 (27%) from traumatic wounds and four (7%) from erysipelas. We found a significant effect (p=0.004) of diet supplemented with OFSP on the wound healing rate.

CONCLUSION

OFSP is a nutritional rehabilitation supplement, characterised by a high content of beta-carotene and carbohydrates. It is associated with shortened wound healing times, reduced discomfort and reduced cost of wound care. Further research should investigate the effect of a diet rich in beta-carotene, in combination with standard medical care, on hard-to-heal wound healing in LMICs.

Birth Weight and Body Composition as Determined by Isotopic Dilution with Deuterium Oxide in 6- to 8-Year-Old South African Children

Low and high birth weight (BW) are associated with obesity later in life; however, this association has not been extensively studied in African countries. This study determines the association between BW and body composition derived from deuterium oxide (D2O) dilution in 6- to 8-year-old South African children (n = 91; 40 boys, 51 girls). BW was recorded retrospectively from the children’s Road-to-Health cards. Weight and height were measured using standard procedures, and D2O dilution was used to determine total body water and, subsequently, to determine body fat. Fatness was classified using the McCarthy centiles, set at 2nd, 85th, and 95th (underfat, overfat and obese). BW correlated with body composition measures, such as body weight (r = 0.23, p = 0.03), height (r = 0.33, p < 0.001), and fat free mass (FFM; r = 0.27, p = 0.01). When multiple regression analysis was employed, BW significantly and positively associated with FFM (β = 0.24, p = 0.013; 95% CI: 0.032; 0.441) and fat mass (β = 0.21, p = 0.02, 95%CI: 0.001; 0.412) in girls and boys combined. A total of 13% of the children had a low BW, with 21% being overweight and 17% obese. More girls than boys were overweight and obese. Intervention strategies that promote healthy uterine growth for optimal BW are needed in order to curb the global obesity pandemic.

Pedi-R-MAPP: The development of a nutritional awareness tool for use in remote paediatric consultations using a modified Delphi consensus

BACKGROUND & AIMS

The Remote Malnutrition Application (R-MAPP) was developed during the COVID-19 pandemic to provide support for health care professionals (HCPs) working in the community to complete remote nutritional assessments, and provide practical guidance for nutritional care. The aim of this study was to modify the R-MAPP into a version suitable for children, Pediatric Remote Malnutrition Application (Pedi-R-MAPP), and provide a structured approach to completing a nutrition focused assessment as part of a technology enabled care service (TECS) consultation.

METHODS

A ten-step process was completed: 1) permission to modify adult R-MAPP, 2) literature search to inform the Pedi-R-MAPP content, 3) Pedi-R-MAPP draft, 4) international survey of HCP practice using TECS, 5) nutrition experts invited to participate in a modified Delphi process, 6) first stakeholder meeting to agree purpose/draft of the tool, 7) round-one online survey, 8) statements with consensus removed from survey, 9) round-two online survey for statements with no consensus and 10) second stakeholder meeting with finalisation of the Pedi-R-MAPP nutrition awareness tool.

RESULTS

The international survey completed by 463 HCPs, 55% paediatricians, 38% dietitians, 7% nurses/others. When HCPs were asked to look back over the last 12 months, dietitians (n = 110) reported that 5.7 ± 10.6 out of every 10 appointments were completed in person; compared to paediatricians (n = 182) who reported 7.5 ± 7.0 out of every 10 appointments to be in person (p < 0.0001), with the remainder completed as TECS consultations. Overall, 74 articles were identified and used to develop the Pedi-R-MAPP which included colour-coded advice using a traffic light system; green, amber, red and purple. Eighteen participants agreed to participate in the Delphi consensus and completed both rounds of the modified Delphi survey. Agreement was reached at the first meeting on the purpose and draft sections of the proposed tool. In round-one of the online survey, 86% (n = 89/104) of statements reached consensus, whereas in round-two 12.5% (n = 13/104) of statements reached no consensus. At the second expert meeting, contested statements were discussed until agreement was reached and the Pedi-R-MAPP could be finalised.

CONCLUSION

The Pedi-R-MAPP nutrition awareness tool was developed using a modified Delphi consensus. This tool aims to support the technological transformation fast-tracked by the COVID-19 pandemic by providing a structured approach to completing a remote nutrition focused assessment, as well as identifying the frequency of follow up along with those children who may require in-person assessment.

Assessment of Anthropometric Indices for Optimal Cut-Offs for Obesity Screening in a South African Adolescent Population

Simple Summary

The diagnosis of obesity in sub-Saharan African children relies on cut-off values for body mass index percentile (pBMI) and waist-to-height ratio (WtHR) established in western populations. Hence, this study assessed anthropometric indices to determine optimal cut-off values for obesity screening in the South African adolescent population. Findings from this study showed that the cut-off value for pBMI was p85.2th, which improved the sensitivity of the test by approximately 30% compared to the CDC recommended BMI percentile of p95.0th. Moreover, the optimal cut-off for WHtR was 0.481, which was close to the recommended cut-off value of 0.5. This study reveals a lower pBMI cut-off value, different from the CDC recommended cut-off, for screening obesity in a South African adolescent population and suggests that the optimal pBMI cut-off for obesity screening may be ethnic-specific.

Abstract

The assessment of obesity in sub-Saharan Africa relies on cut-offs established from western populations. This study assessed anthropometric indices to determine optimal cut-off values for obesity screening in the South African adolescent population. A cross-sectional study involving 1144 (796 females and 348 males) adolescents aged 11–17 years from the Eastern Cape Province of South African was conducted. Anthropometric parameters were measured. Receiver operating characteristic (ROC) analysis was performed to assess the sensitivity and specificity of obesity screening tools and establish cut-offs. The optimal cut-offs for obesity in the cohort using waist-to-height ratio (WHtR) as reference were: neck circumference (NC) = 30.6 cm, mid-upper arm circumference (MUAC) = 25.9 cm, waist circumference (WC) = 75.1 cm, hip circumference (HC) = 92.15 cm and body mass index percentile (pBMI) = p85.2th. The new pBMI cut-off value at p85.2th improved the sensitivity of the test by approximately 30% compared to the CDC recommended BMI percentile (pBMIr) of p95.0th. When pBMI was used as reference, the optimal cut-offs in the cohort were: WHtR = 0.481, NC = 30.95 cm, MUAC = 27.95 cm, WC = 76.1 cm and HC = 95.75 cm. The WHtR optimal cut-off of 0.481 was close to the recommended cut-off value of 0.5. The predicted prevalence of obesity obtained using cut-offs from ROC analysis was higher than those from recommended references. All cut-off values for the various anthropometric measures generally increased with age for all percentile ranges. This study reveals a lower pBMI cut-off value, different from the CDC recommended cut-off, for screening obesity in a South African adolescent population. The study has established that the optimal pBMI cut-off for obesity screening may be ethnic-specific.

Subcutaneous Adipose Tissue Measured by B-Mode Ultrasound to Assess and Monitor Obesity and Cardio-Metabolic Risk in Children and Adolescents

Simple Summary

The prevention and treatment of childhood and adolescent overweight and obesity raises the need for accurate body fat assessment. Precise methods are at high technical expense, require exposure to ionizing radiation and are limited to institutional investigations, while common body indicators fail to identify excess body fat. Subcutaneous adipose tissue measured by ultrasound is an alternative approach, which was evaluated in relation to commonly applied body indicators to assess cardio–metabolic risk and its applicability in the field. Subcutaneous adipose tissue measured by ultrasound indicated a clear advantage over commonly applied body indicators and implies that severe body fat assessment errors are to be expected when BMI is used as a measure for body fatness in children. Children or adolescents with identical BMIs may have large differences (>200%) in their amount of subcutaneous adipose tissue. Ultrasound provides an easily applicable, reliable and safe method for accurate assessment of obesity and monitoring treatment responses in children and adolescents at cardio–metabolic risk.

Abstract

Monitoring of children at heightened risk of cardio–metabolic diseases raises the need for accurate assessment of obesity. A standardized approach for measuring subcutaneous adipose tissue (SAT) by bright-mode ultrasound was evaluated in relation to body indices and anthropometry in a cross-sectional sample of 76 South African children (7–10 years) and 86 adolescents (13–17 years) to assess cardio–metabolic risk. SAT was higher in girls as compared to boys (children: 50.0 ± 21.7 mm > 34.42 ± 15.8 mm, adolescents: 140.9 ± 59.4 mm > 79.5 ± 75.6 mm, p < 0.001) and up to four times higher in adolescents than in children. In children, measures of relative body weight showed only a poor correlation to SAT (BMI: r = 0.607, p < 0.001), while in adolescents, BMI correlated high with SAT (r = 0.906, p < 0.001) based on high rates of overweight and obesity (41.8%). Children with identical BMIs may have large differences (>2–3-fold) in their amount of SAT. The moderate association to systolic (r = 0.534, r = 0.550, p < 0.001) and diastolic blood pressure (r = 0.402, r = 0.262, p < 0.001) further substantiates that SAT measured by ultrasound provides an accurate, safe and easy applicable approach for monitoring in children and adolescents at cardio–metabolic risk.

Comparison of different BMI cut-offs to screen for child and adolescent obesity in urban China

Objectives:

To determine which set of BMI cut-offs is the most appropriate to define child and adolescent obesity in urban China.

Design:

A cross-sectional study was carried out between 1 November and 31 December in 2017.

Setting:

Community Healthcare Center in Minhang District, Shanghai, China.

Participants:

A total of 12 426 children and adolescents aged 7–17 years were selected by cluster random sampling. Bioelectrical impedance analysis was the gold standard to measure body composition.

Results:

Comparisons of three sets of BMI cut-offs by sensitivity and κ value revealed that the Working Group on Obesity in China (WGOC) (sensitivity 39·9–84·0 %; κ 0·51–0·79) and WHO (sensitivity 25·5–74·5 %; κ 0·35–0·78) cut-offs were not superior to the International Obesity Task Force (IOTF) (sensitivity 47·9–92·4 %; κ 0·58–0·85) cut-offs across all subgroups. The WGOC and WHO cut-offs yielded higher misclassification rates, in the worst case, categorising 11·2 % of girls with high adiposity as normal and 44·4 % of them as overweight, while the IOTF cut-offs categorised 2·3 % as normal and 30·7 % as overweight. Individuals who were classified by the IOTF cut-offs as overweight had the lowest ratios of high adiposity (4·2–41·6 %) than by the BMI cut-offs for each subgroup. Among pubertal girls, none of the BMI-based cut-offs indicated excellent agreement with body fat percentage, and κ value of the WHO cut-offs (0·35 (95 % CI 0·29, 0·41)) was lower than the other two sets of BMI cut-offs (all P < 0·001).

Conclusions:

The IOTF cut-offs for Asian should be recommended for child obesity screening in urban China. Pubertal individuals need a more accurate indicator of obesity screening.