Relationship between body mass index and insulin measured during oral glucose tolerance testing in severely obese children and adolescents

PRIMARY OBJECTIVE: The study evaluated the accuracy of body mass index (BMI) in detecting hyperinsulinaemia during oral glucose tolerance testing (OGTT) in severely obese children. RESEARCH DESIGN: A cross-sectional study was carried out. MATERIALS AND METHODS: A total of 118 obese children and adolescents (49 females and 69 males) aged 6-19 years were consecutively studied at an outpatient paediatric clinic. Hyperinsulinaemia was defined as a value of log-transformed fasting insulin >/= 80th percentile and OGTT hyperinsulinaemia as a value of the log-transformed area under the curve (AUC) of insulin >/= 80th percentile. The study hypothesis was tested using a logistic regression model with hyperinsulinaemia as the outcome variable and the z-score of BMI corrected for age (z-BMI(age)) as the predictor variable. Receiver-operator characteristic (ROC) curves were used to evaluate accuracy. RESULTS: The mean (SD) BMI for age of the children was 28.6 (4.0) kg m(-2), corresponding to 2.2 (0.5) standard deviation scores. The odds ratio (OR) of OGTT hyperinsulinaemia was 2.0 (95% CI 1.2-3.3; p = 0.007) for each unit increase of z-BMI(age) and the corresponding ROC-AUC was 0.74 (95% CI 0.61-0.86; p = 0.0001). In comparison, the OR of fasting hyperinsulinaemia was 1.1 (95% CI 0.7-1.7; p = 0.716) for each unit increase of z-BMI(age) and the corresponding ROC-AUC was 0.49 (95% CI 0.35-0.62; p = 0.863). CONCLUSION: BMI is reasonably accurate in detecting OGTT hyperinsulinaemia in severely obese children.     

Longitudinal changes in BMI z-scores among 45 414 2–4-year olds with severe obesity

Background: BMI z-scores (BMIz) based on the Centers for Disease Control and Prevention (CDC) growth charts among children do not accurately characterise BMI levels among children with very high BMIs. These limitations may be particularly relevant in longitudinal and intervention studies, as the large changes in the L (normality) and S (dispersion) parameters with age can influence BMIz.

Aim: To compare longitudinal changes in BMIz with BMI expressed as a percentage of the 95th percentile (%BMIp95) and a modified z-score calculated as log(BMI/M)/S.

Subjects and methods: A total of 45 414 2–4-year-olds with severe obesity (%BMIp95?≥?120).

Results: Changes in very high BMIz levels differed from the other metrics. Among severely obese 2-year-old girls, for example, the mean BMIz decreased by 0.6 SD between examinations, but there were only small changes in BMIp95 and modified BMIz. Some 2-year-old girls had BMIz decreases of >1 SD, even though they had large increases in BMI, %BMIp95 and modified BMIz.

Conclusions: Among children with severe obesity, BMIz changes may be due to differences in the transformations used to estimate levels of BMIz rather than to changes in body size. The BMIs of these children could be expressed relative to the 95th percentile or as modified z-scores.     

Receiver operating characteristic (ROC) curve analysis in 5–10-year-old Bengalee girls from Calcutta,India

Summary.?Objective: The purpose of the present cross-sectional study was to evaluate the sensitivity (SN) and specificity (SP) of body mass index (BMI) and skinfolds thickness: BMI (subcutaneous to overall fat) in detecting excess adiposity in pre-menarcheal Bengalee girls.

Methods: Four hundred and fifty Bengalee girls aged 7.4 ± 1.16 years (mean ± SD; range: 5–10 years) from Calcutta were studied. Anthropometric measures – namely height, weight, circumference of mid upper arm, waist and hip, and skinfold thickness at biceps, triceps, subscapular and suprailiac – were taken from all participants using standard protocols. BMI and the log-transformed sum of four (biceps, triceps, subscapular, suprailiac) skinfolds (log₁₀ SF4) were computed subsequently. Values of log₁₀ SF4 were then converted into seven percentiles category (5th, 10th, 25th, 50th, 75th, 85th and 95th). Excess adiposity was defined as a level of log₁₀ SF4 greater than the internally derived 85th percentile (log₁₀ SF4>85th percentile). SN and SP of each internally derived percentile of BMI and log₁₀ SF4:BMI in detecting excess adiposity were then computed.

Results: SN and SP were 0.49 and 0.94 for the 95th percentile of BMI, and 0.76 and 0.82 for the 95th percentile of log₁₀ SF4:BMI. Moreover, there was a considerable decrease in overall misclassification with the use of log₁₀ SF4:BMI instead of BMI at the 95th percentile (11.2% vs 32%).

Conclusion: Percentiles of BMI in the study had higher SP but low SN in detecting excess adiposity. The use of log₁₀ SF4:BMI, on the other hand, had the merit of increasing SN in a screening programme to evaluate excess adiposity in Bengalee children aged 5–10 years.     

Association between childhood obesity,cognitive development,physical fitness and social-emotional wellbeing in a transitional economy

Background: It has been suggested that obese children have lower cognitive function, demonstrate poorer physical performance and are more susceptible to social-emotional problems.

Aims: To describe associations between human physical growth, cognitive development, physical fitness and social-emotional characteristics of obese and non-obese children and to verify the predictors of intellectual coefficient by socioeconomic status (SES).

Subjects and methods: A sample of 107 non-obese (N-Ob) children [?1?z-score body mass index (BMI) ≤1?z-score] and 108 obese (Ob) children [2 z-score ≤BMI ≤5?z-score] from a larger cohort was evaluated. Intellectual coefficient (IQ), social-emotional wellbeing (SEW), 6-minute walk test (6MWT) and SES (mid-low, low and very low) were assessed.

Results: Ob children were taller, heavier and present more height for age and BMI than N-Ob children (p?r?=?0.14), 6MWT and BMI z-score (r?=??0.18) and 6MWT and SEW (r?=?0.15) was found. Multiple regression analysis revealed that BMI z-score had a negative impact on IQ in the mid-low SES sub-group and that SEW had a positive effect on IQ in the very-low SES sub-group.

Conclusions: In Chilean pre-school children from low-income families cognitive ability varied according to SES.     

Blood pressure effects of adiposity in non-overweight children aged 6–17 years

Background: Obesity is a well-established risk factor of elevated blood pressure; however, the relationships between normal weight status and the risk of hypertension and pre-hypertension are not clear.

Aim: The aim of this study is to describe the blood pressure effects of adiposity in non-overweight children.

Methods and results: In total, 588 097 non-overweight children aged 6–17?years were included from the National Surveys on Students’ Constitution and Health. A non-linear relationship was found between age- and gender-standardised body mass index (BMI) z-score and pre-hypertension and hypertension, respectively. The odds ratios and 95% confidence intervals [ORs (95% CIs)] of pre-hypertension were 0.61 (0.59–0.63), 0.67 (0.65–0.68), 0.83 (0.83–0.84), 1.00 (reference), 1.13 (1.12–1.14), 1.18 (1.16–1.20) and 1.20 (1.18–1.22) for BMI z-scores of ?1.2, ?1.0, ?0.5, 0 (reference), 0.5, 0.7 and 0.8, respectively. The ORs (95% CIs) of hypertension were 0.56 (0.54–0.58), 0.62 (0.61–0.64), 0.81 (0.80–0.82), 1.00 (reference), 1.17 (1.16–1.18), 1.23 (1.22–1.5) and 1.27 (1.24–1.29) for BMI z-scores of ?1.2, ?1.0, ?0.5, 0 (reference), 0.5, 0.7 and 0.8, respectively. The above-mentioned associations were consistent in sub-group analysis by age, gender and height.

Conclusions: Non-linear relationships of BMI z-scores with pre-hypertension and hypertension were found in non-overweight children. Interventions to control blood pressure are also important in non-overweight children.     

BMI z-score is the optimal measure of annual adiposity change in elementary school children

Background: BMI or BMI% adjusted for age has been identified as the optimal measure of short-term adiposity change in kindergarten children aged 29–68 months. The optimal measure of annual adiposity change in older age children, however, has not been determined.

Aim: To identify the optimal measure of annual adiposity change for Japanese children aged 6–12 years.

Subjects and methods: A cohort of 669 Japanese children in one private school in Tokyo in whom height and weight were measured annually between 6 and 12 years. Each child's annual variability in adiposity was summarized by the standard deviation (SD) of BMI and BMI% adjusted for age, BMI z-score and BMI centile. The SDs were compared in overweight and non-overweight children and correlated with each child's baseline BMI z-score.

Results: The within-child BMI, BMI% and BMI centile SDs were significantly different in overweight and non-overweight children, while the BMI z-score SDs were similar in the two groups. Furthermore, the within-child BMI, BMI% and BMI centile SDs were inversely correlated with baseline BMI z-score, whereas BMI z-score SDs were not, with the exception of measurements for grade 1–2 children.

Conclusion: The BMI z-score is the optimal measure of annual adiposity change for elementary school children.     

Influence of different behavioural factors and obesity status on systolic blood pressure among pre-school children

Aim: The aim of this study was to examine the association between sleeping time (SLT), time spent using screen (ST) and weight status with Systolic Blood Pressure (SBP) among pre-school children.

Subjects and methods: The sample comprised 628 pre-school children (50% female), aged 3–6 years-old. SLT and ST were reported by parents. BMI values were categorized according to IOTF. SBP cut points were based on SBP percentiles for age, sex and height. ST was dichotomized according to the following criteria: ≤1 hour vs >1 hour and SLT: ≤10.5 hours vs >10.5 hours. Participants were then categorized into one of four category profiles: Low ST/High SLT; High ST/Low SLT; Low ST/Low SLT and High ST/High SLT.

Results: Children assigned to the High ST/Low SLT group were 2-times more likely to have high SBP values compared to those who were assigned to the Low ST/High SLT group (OR?=?2.4; 95% CI?=?1.1–5.1). Furthermore, those who were assigned as overweight and obese were more likely to be classified as having elevated BP (OR?=?1.8; 95% CI?=?1.1–3.2 for overweight and OR?=?3.1; 95% CI?=?1.6–5.8 for obese, respectively).

Conclusion: The data showed that high ST exposure time and low SLT are associated with enhanced blood pressure in children at pre-school.     

Waist circumference to height ratio predicts inflammatory risk in children

Background: The increase in obesity, especially the increase of visceral fat, has been directly associated with health risk. Additionally, a waist-to-height ratio (WHtR) (0.5) has been proposed as an indicator of early health risk.

Aims: To test the association between anthropometric measurements and inflammatory mRNA expression and to evaluate the effectiveness of WHtR to predict inflammatory risk in children.

Subjects and methods: Anthropometric measurements and fasting blood samples were collected in 94 Brazilian children (46 boys) aged 9–11 years. Children were identified as being at inflammatory risk based on cytokine mRNA expression levels at and above the 75th percentile. Inflammatory cytokine mRNA expression levels were determined through buff-coat using real-time polymerase chain reaction.

Results: Body mass index (BMI), waist circumference (WC) and WHtR showed moderate-to-strong association with inflammatory cytokine mRNA gene expression. WHtR?=?0.51 was the most accurate cut-off point in distinguishing children at inflammatory risk. Compared with children with WHtR <0.51, children with a WHtR ≥0.51 presented an odds ratio of 2.643 (95% CI?=?1.749–3.994) for both diagnosed IL-6 and MCP-1 above the 75th percentile and 2.796 (95% CI?=?1.802–4.338) for TNF-α above the 75th percentile. WHtR?=?0.50 presented the same values of sensitivity and odds ratio and ～7% lower specificity compared to WHtR?=?0.51.

Conclusion: Anthropometric measurements have shown a moderate-to-strong association with the mRNA expression of inflammatory genes and a WHtR of 0.5 could serve as a cut-off point, suggesting increased risk of inflammatory responses.     

Weight and body mass index (BMI): current data for Austrian boys and girls aged 4 to under 19 years

Background: BMI reference charts are widely used to diagnose overweight, obesity and underweight in children and adolescents.

Aim: To provide up-to-date national reference values for Austria.

Methods: A cross-sectional sample of over 14?500 children and adolescents (4–19 years) stratified by provinces according to age- and sex-specific population proportions was drawn via schooling institutions (kindergartens, schools and vocational colleges). The generalized additive models for location, scale and shape were used for a flexible estimation of percentile curves.

Results: Austrian boys and girls have higher average weight compared with previous prevalence data. BMI centiles matching BMI values at age 18 years, which are used for defining thinness, overweight and obesity in adults, were calculated. In Austria, using reference values as thresholds, ～18% of boys and 12% of girls are overweight (with thresholds passing through BMI 25.00–29.99?kg/m² in adults) and 5% of boys and 3% of girls are obese (with thresholds passing through BMI ≥30.00?kg/m² in adults).

Conclusion: Overweight and obesity are common in Austria and their prevalence is increasing (using the same IOTF reference for international comparison). Up-to-date national BMI reference values are provided to classify children and adolescents according to the proposed overweight and obesity thresholds.     

Diagnostic performance of Body Mass Index,Waist Circumference and the Waist-to-Height Ratio for identifying cardiometabolic risk in Scottish pre-adolescents

Background: Limited studies have examined the diagnostic performance of body mass index (BMI), waist circumference (WC) or waist-to-height ratio (WHtR) for identifying cardiometabolic risk (increased clustered glucose, triglycerides, mean arterial pressure and inv-HDL-cholesterol) in pre-adolescent youth.

Aim: To compare the utility of BMI, WC and WHtR as predictors of cardiometabolic risk (CMR) in Scottish pre-adolescent children.

Subjects and methods: A cross-sectional analysis of 223 Scottish children (55.2% boys, mean age =8.4 years) was undertaken. BMI, WC and WHtR were used as exposure variables within multivariate logistic regression analysis and ROC analysis to examine the utility of these anthropometrical indices in identifying those at cardiometabolic risk.

Results: Individuals with an elevated WHtR, WC and BMI were 3.51 (95% CI?=?1.71–7.23; p?p =?.002) and 2.59 (95% CI?=?1.42–4.73; p?=?.002) times more likely to be at cardiometabolic risk, respectively. The areas under the curves [AUC] to identify children with cardiometabolic risk were significant and similar among anthropometric indices (AUC’s?=?0.60–0.65). When stratified by BMI, both WC and WHtR demonstrated a fair-to-good ability for identifying those at cardiometabolic risk (AUC?=?0.75–0.81).

Conclusions: Findings suggest that the combination of BMI with either WC or WHtR may provide an added benefit in the assessment of cardiometabolic risk amongst pre-adolescents.     

BMI-for-age in South Asian children of 0–20 years in the Netherlands: secular changes and misclassification by WHO growth references

Background: South Asians are prone to cardiometabolic disease at lower BMI levels than most other ethnic groups, starting in childhood. The magnitude of BMI misclassifications is unknown.

Aim: To compare the BMI distribution of contemporary South Asian 0–20?year olds in the Netherlands with: (1) The South Asian norm reference (secular trends); and (2) The WHO child growth standard and reference.

Subjects and methods: The BMI-for-age distribution of 6677 routine measurements of 3322 South Asian children, aged 0–20 years, was described with the LMS method and BMI z-scores.

Results: The BMI distribution in South Asian 0–4?year olds was almost similar to the norm reference (mean BMI z-score?=?0.11, skewness?=?0.31, SD?=?1.0), whereas in 5–19?year olds the distribution had shifted upwards (mean?=?0.53) and widened (skewness?=??0.12, SD?=?1.08). Overweight (incl. obesity) and obesity peaked at 8–10 years, at 45–48% and 35–37%, respectively. Relative to the WHO references, the BMI distribution was left-shifted at ages 0–4 years (mean BMI z-score?=??0.46, skewness?=?0.23, SD?=?0.98) and widened at ages 5–20 years (mean?=?0.05; skewness?=??0.02, SD?=?1.40). At most ages, thinness rates were significantly higher and obesity rates lower than based on South Asian norms.

Conclusions: A secular change of BMI-for-age in South Asian children mostly affected children >4 years. WHO references likely under-estimate overweight and obesity rates in South Asian children.     

Maternal vitamin D status and infant anthropometry in a US multi-centre cohort study

Background: Maternal vitamin D status in pregnancy is linked to foetal growth and may impact infant growth.

Aim: This study examined the association between maternal vitamin D status and infant anthropometry.

Subjects and methods: Data came from n?=?2473 mother–child pairs from the 12-site US Collaborative Perinatal Project (1959–1965). Maternal serum 25-hydroxyvitamin D (25(OH)D) was measured at?≤?26 weeks gestation. Multivariate-adjusted linear mixed models were used to relate maternal vitamin D status to infant z-scores for length (LAZ), head circumference (HCZ), weight (WAZ) and BMI (BMIZ), measured at birth and 4, 8 and 12 months.

Results: Infants with maternal 25(OH)D ≥30?nmol/L vs <30?nmol/L had LAZ and HCZ measures 0.13 (95% CI?=?0.03–0.23) and 0.20 (95% CI?=?0.11–0.28) units higher, respectively, across the first year of life. Similar differences in WAZ and BMIZ at birth were resolved by 12 months of age due to interactions indicating steeper age slopes in infants with maternal 25(OH)D <30?nmol/L.

Conclusion: Low maternal vitamin D status was associated with deficits at birth in infant weight and BMI that were recouped across the first year of life; associations with reduced measures of linear and skeletal growth were sustained from birth to 12 months.     

Nutritional status,especially body mass index,from birth to adulthood and lung function in young adulthood

Objective: The study assessed the impact of body mass index (BMI) at birth, infancy, and adulthood, and waist circumference on lung function.

Methods: Using a longitudinal design 1221 Chilean young adults were studied. A standardized respiratory questionnaire was used. Forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), height, weight and waist circumference were measured. Data at birth and at 1 year were obtained from clinical notes.

Results: Males with a BMI?≥?30 and women with a BMI?<?20 had a lower FEV₁ (?230 mL, 95% CI ?363 to ?98; ?106 mL, 95% CI ?211 to ?0.18, respectively). In both sexes those with a BMI 20–25 had the highest FEV₁ and FVC. In males there was a negative association between waist circumference and FEV₁ and FVC while in women the middle tertile had the highest FEV₁ and FVC. There was an association between birthweight and BMI at birth, and FEV₁ in men, when unadjusted for other measurements.

Conclusions: BMI and waist circumference in adulthood make a greater impact on lung function in adulthood than anthropometric measurements at birth and infancy. Proxy measures of fatness in adulthood reduce lung function, but the pattern between fatness and lung function by sex may be different.     

The relationship between resting blood pressure,body mass index and lean body mass index in British children

Background: Elevated blood pressure (BP) in childhood is associated with overweight and obesity. However, lean body mass index (LBMI, cm²/kg) has been suggested as a better means than body mass index (BMI, kg/m²) by which to consider the relations between weight status and health indices in children.

Objective: To assess the relationship between resting BP and weight status in youth whilst considering BMI and LBMI when examining this issue.

Methods and procedures: Height, body mass and resting blood pressure were assessed in 384 boys and 277 girls, aged 11–14 years from Central England.

Results: SBP was significantly lower in ‘normal weight’ children compared to overweight and obese children and in overweight compared to obese children (both p = 0.0001). DBP was significantly lower in ‘normal weight’ children compared to those classified as overweight (p = 0.006). BMI and LBMI were both significant predictors of SBP and DBP (p = 0.0001). However, LBMI was normally distributed, unlike BMI, and was a better predictor of BP than BMI.

Conclusions: Overweight and obesity is associated with higher resting BP in British children. However, when examining the effect of weight status on BP, the researcher should consider use of LBMI over BMI.     

Meeting abstracts from the 10th International Conference on cGMP: Generators,Effectors and Therapeutic Implications

Background

The impact of metabolically healthy obesity (MHO) on kidney dysfunction remains debatable. Moreover, few studies have focused on the early stages of kidney dysfunction indicated by hyperfiltration and mildly reduced eGFR. Thus, we aimed to investigate the association between the MHO and early kidney dysfunction, which is represented by hyperfiltration and mildly reduced estimated glomerular filtration rate (eGFR), and to further explore whether serum uric acid affects this association.

Methods

This cross-sectional study enrolled 1188 residents aged ≥ 40 years old from Yonghong Communities. Metabolically healthy phenotypes were categorized based on Adult Treatment Panel III criteria. Obesity was defined as body mass index (BMI) ≥ 25 kg/m². Mildly reduced eGFR was defined as being in the range 60 < eGFR ≤ 90 ml/min/1.73m². Hyperfiltration was defined as eGFR > 95th percentile after adjusting for sex, age, weight, and height.

Results

Overall, MHO accounted for 12.8% of total participants and 24.6% of obese participants. Compared to metabolically healthy non-obesity (MHNO), MHO was significantly associated with an increased risk of mildly reduced eGFR (odds ratio [OR] = 1.85, 95% confidence interval [CI]  1.13–3.01) and hyperfiltration (OR = 2.28, 95% CI 1.03–5.09). However, upon further adjusting for uric acid, the association between the MHO phenotype and mildly reduced eGFR was reduced to null. Compared with MHNO/non-hyperuricemia, MHO/non-hyperuricemia was associated with an increased risk of mildly reduced eGFR (OR = 2.04, 95% CI  1.17–3.58), whereas MHO/hyperuricemia was associated with an observably increased risk (OR = 3.07, 95% CI  1.34–7.01).

Conclusions

MHO was associated with an increased risk of early kidney dysfunction, and the serum uric acid partially mediated this association. Further prospective studies are warranted to clarify the causality.

     

High prevalence of cardiometabolic risk features in adolescents with 47,XXY/Klinefelter syndrome

Klinefelter syndrome (KS) occurs in 1:600 males and is associated with high morbidity and mortality due to diabetes and cardiovascular disease. Up to 50% of men with KS have metabolic syndrome, a cluster of features conferring increased risk for diabetes and cardiovascular disease. These cardiometabolic (CM) risk features have not been studied in adolescents with KS. The objective of this cohort study was to compare CM risk features in adolescents with KS to controls matched for sex, age, and BMI z score. Fifty males with KS (age 10–17 years) were well‐matched to male controls (n = 50) for age (14.0 ± 1.7 vs. 14.0 ± 1.5 years) and BMI z score (0.3 ± 1.3 vs. 0.4 ± 1.2). Three CM risk features were present in 30% of adolescents with KS compared to 12% of controls (RR 2.5, 95% CI 1.1–5.9, p = .048). The KS group had significantly lower HDL cholesterol (p = .006), higher triglycerides (p < .001), and greater waist circumference percentile (p < .001). Despite a normal BMI, the prevalence of CM risk features was very high in adolescents with KS, particularly for central adiposity and dyslipidemia. The pathophysiology of this metabolic profile independent of obesity needs further investigation to facilitate prevention of the high morbidity of cardiovascular disease and diabetes in this population. ClinicalTrials.gov identifiers: NCT01585831 and NCT02723305.     

Evolution of the nutritional situation of indigenous and non-indigenous Chilean schoolchildren

Background: Latin American countries show accelerated but ethnically or socially differentiated changes in their epidemiological profiles.

Aim: The present study examined the evolution of the nutritional situation (1997–2005) in Chilean schoolchildren as related to ethnical origin (Mapuche).

Subjects and methods: Using official databases, stunting (height/age ≤ ? 2 z-scores), undernutrition (body mass index (BMI) ≤ ? 2 z-scores) and obesity (BMI ≥95 percentile) were ascribed in first-grade schoolchildren. Ethnic groups were assigned by native parents’ surnames (none, one and two).

Results: Based on 1 757 155 children (average age: 76.3 months), in 1997 stunting reached 8.4%, 4.8% and 3.1% in children with two, one and no Mapuche surnames, respectively. In 2005 it fell to 3.7%, 3.1% and 2.6% – a marked decrease in those with two Mapuche surnames (p<0.001). Obesity in 1997 was 11.8%, 12.8% and 13.3%, whilst in 2005 it changed to 17.5, 18.5 and 18.6%, respectively, demonstrating a similar trend to obesity in all groups (p=0.153). Undernutrition was rare (<1.1%) and stable. Poverty decreased clearly among the Mapuche population in this period.

Conclusion: The marked decrease in stunting in children with a strong indigenous background seems related to a decrease in poverty over the period. Yet, the increase of obesity in all groups deserves further analysis.     

Fitness and metabolic syndrome in obese fatty liver children

Background: Metabolic Syndrome (MS) is highly prevalent among obese children with fatty liver. However, it is well-known that there is a lower prevalence of MS in individuals with higher cardiorespiratory fitness (CRF).

Aim: To analyse the association between CRF with features of the MS in obese children that present fat liver indicators, namely abnormal alanine aminotransferase (ALT) values.

Methods: A total of 79 obese students (40 girls), 10–11 year-olds ( ± 0.60), with abnormal serum ALT from Porto public schools comprised the sample. Measurements included CRF (20-metre Shuttle Run Test), Metabolic Risk Factors (MRF), according to MS International Diabetes Federation criteria, ALT values (Cholestech LDX^® analyser) and maturational stage (Tanner criteria). Logistic regression analysis was used to determine the influence of CRF on MRF adjusted for sex, maturation, and BMI.

Results: The logistic regression showed that, despite being classified as being obese and presenting abnormal levels of ALT, those classified as fit were less likely to have MS than their unfit counterparts (OR = 0.52; p ≤ 0.05).

Conclusion: Obese-fit children with abnormal ALT values have a significant reduction in the likelihood to be classified as having MS, even after adjustments for gender, maturation and BMI, Thus, CRF might be an important factor for tackling fatty liver among obese.     

Development and Validation of a Predictive Equation for Lean Body Mass in Children and Adolescents

Background: Lean body mass (LBM) is not easy to measure directly in the field or clinical setting. Equations to predict LBM from simple anthropometric measures, which account for the differing contributions of fat and lean to body weight at different ages and levels of adiposity, would be useful to both human biologists and clinicians.

Aim: To develop and validate equations to predict LBM in children and adolescents across the entire range of the adiposity spectrum.

Subjects and methods: Dual energy X-ray absorptiometry was used to measure LBM in 836 healthy children (437 females) and linear regression was used to develop sex-specific equations to estimate LBM from height, weight, age, body mass index (BMI) for age z-score and population ancestry. Equations were validated using bootstrapping methods and in a local independent sample of 332 children and in national data collected by NHANES.

Results: The mean difference between measured and predicted LBM was ? 0.12% (95% limits of agreement ? 11.3% to 8.5%) for males and ? 0.14% ( ? 11.9% to 10.9%) for females. Equations performed equally well across the entire adiposity spectrum, as estimated by BMI z-score. Validation indicated no over-fitting. LBM was predicted within 5% of measured LBM in the validation sample.

Conclusion: The equations estimate LBM accurately from simple anthropometric measures.     

Prevalence of overweight and obesity in Chinese children and adolescents from 2015

Background: To update the prevalence of overweight and obesity in children and adolescents from 2015.

Methods: Data for this study were obtained from children and adolescents aged 7–17?years with measured weight and height from the National Surveys on Chinese Students’ Constitution and Health in 2015.

Results: Measurements from 29 418 children and adolescents (14 480 boys and 14 938 girls) were analysed. Among children and adolescents aged 7–17?years, the prevalence of obesity was 13.2% (95% CI?=?12.8–13.7%) in 2015. Moreover, the prevalence of obesity for children aged 7–12?years (20.3% (95% CI?=?19.5–21.1%)) was significantly higher than in adolescents aged 13–17?years (9.6% (95% CI?=?9.2–10.0%)) (p?< 0.001).

Comment: Obesity was much worse in children than adolescents in China; future studies are warranted to understand why these differences may be occurring.