A simple equation to estimate body fat percentage in children with overweightness or obesity: a retrospective study

Positive effect of combined exercise on adipokines levels and pubertal signs in overweight and obese girls with central precocious puberty

Background

The prevalence of precocious puberty is increasing. Obesity has been demonstrated to be associated with changes in the adipokine profile and incidence of early puberty in girls. This study assessed the pubertal signs, the levels of adiponectin, resistin, and tumor necrosis factor-alpha (TNF-α) after 12 weeks of combined exercise and 4 weeks of detraining in overweight and obese girls with precocious puberty.

Methods

Thirty overweight and obese girls (aged 7–9) with precocious puberty, who had received Triptorelin, were randomly divided into two groups (15 exercise and 15 control). Initially, serum levels of adiponectin, resistin, TNF-α, luteinising hormone (LH), and follicle-stimulating hormone (FSH) and the signs of puberty progression (bone age, uterine length, and ovarian volume) were measured. The exercise group performed 60 min of combined (aerobic and resistance) exercise three times/week for 12 weeks. The control group did not receive any exercise. 48 h after the last training session and after 4 weeks of detraining, all research variables were measured (also in the control group). The statistical method used for data analysis was repeated measures ANOVA.

Results

In the exercise group, adiponectin significantly increased and resistin significantly decreased after 12 weeks. After 4 weeks of detraining, adiponectin significantly decreased, but resistin significantly increased. TNF-α levels did not change significantly during the study. There was no significant difference in all of the factors in the control group. Throughout the 16-week study period, the rate of puberty and LH significantly decreased in both exercise and control groups, but FSH, LH/FSH and ovarian volume significantly decreased in the exercise group alone (P<0.05).

Conclusions

Combined exercise increased adiponectin and decreased resistin and the rate of puberty. However, after 4 weeks of detraining, these effects diminished but did not disappear.

Trial registration

IRCT, IRCT56471. Registered 25 may 2021 - Retrospectively registered, https://fa.irct.ir/user/profile

Estimation of Body Fat Percentage for Clinical Pharmacokinetic Studies in Children

Obesity is a prevalent childhood condition and the degree of adiposity appears likely to be an important covariate in the pharmacokinetics (PKs) of many drugs. We undertook these studies to facilitate the evaluation and, where appropriate, quantification of the covariate effect of body fat percentage (BF%) on PK parameters in children. We examined two large databases to determine the values and variabilities of BF% in children with healthy body weights and in those with obesity, comparing the accuracy and precision of BF% estimation by both clinical methods and demographically derived techniques. Additionally, we conducted simulation studies to evaluate the utility of the several methods for application in clinical trials. BF% was correlated with body mass index (BMI), but was highly variable among both children with healthy body weights and those with obesity. Bio-impedance and several demographically derived techniques produced mean estimates of BF% that differed from dual x-ray absorptiometry by < 1% (accuracy) and a SD of 5% or less (precision). Simulation studies confirmed that when the differences in precision among the several methods were small compared with unexplained between-subject variability of a PK parameter, the techniques were of similar value in assessing the contribution of BF%, if any, as a covariate for that PK parameter. The combination of sex and obesity stage explained 68% of the variance of BF% with BMI. The estimation of BF% from sex and obesity stage can routinely be applied to PK clinical trials to evaluate the contribution of BF% as a potential covariate.

Validity of Slaughter Equations and Bioelectrical Impedance Against Dual-Energy X-Ray Absorptiometry in Children

OBJECTIVE

This study aimed to 1) analyze the criterion validity of the Slaughter equations (Slg-Eq) and bioelectrical impedance analysis (BIA) to estimate body fat percentage (BFP) and fat mass index (FMI) at different degrees of obesity in children compared with dual-energy x-ray absorptiometry (DXA) and 2) determine their agreement over time.

METHODS

Ninety-two children with overweight or obesity (10.0 [SD 1.2] years; 34.8% girls) participated in this 20-week study. Anthropometric, BIA, and DXA measurements were performed.

RESULTS

Both Slg-Eq and BIA methods underestimated BFP and FMI against DXA, and the bias was markedly larger with BIA (mean absolute percentage error = 11% for Slg-Eq vs. 18%-21% for BIA); a larger underestimation was observed in girls compared with boys for Slg-Eq (P ≤ 0.001), and the observed underestimation in adiposity was reduced as weight status increased. Systematic errors were kept constant over time, so no large differences between methods were observed in the change in adiposity.

CONCLUSIONS

At the group level, Slg-Eq provides a more valid estimation of BFP and FMI than BIA. At the individual level, Slg-Eq shows larger estimation errors. The validity of these methods might differ in sex and weight status. Nevertheless, both methods seem to be valid for monitoring changes in adiposity.

Effectiveness of a socially adapted intervention in reducing social inequalities in adolescence weight. The PRALIMAP-INÈS school-based mixed trial

BACKGROUND

A high prevalence of overweight/obesity among low socioeconomic status adolescents contributes to health inequalities. However, evidence-based interventions for reducing social inequalities in adolescent weight are lacking. We aimed to investigate whether strengthened care management for adolescents with low socioeconomic status has an equivalent effect in reducing overweight as standard care management in adolescents with high status.

METHODS

PRALIMAP-INÈS was a multicentre trial including 35 state-run high and middle schools in the north-eastern France. A population-based sample of 1639 adolescents aged 13-18 years with screened and clinically confirmed overweight/obesity were proposed for inclusion and divided into two groups by the Family Affluence Scale score: advantaged (score > 5), receiving standard care management (A.S) and less-advantaged randomly assigned to two groups (1:2 ratio): standard care management (LA.S) and standard and strengthened care management (LA.S.S). Interventions were based on the proportionate universalism principle: universal standard care for all groups and proportionate care for the LA.S.S group. Main outcome was body mass index z-score (BMIz) assessed before and 1 year after inclusion.

RESULTS

A total of 1419 adolescents were included and 1143 followed up at 1 year: 649 in A.S, 158 in LA.S and 336 in LA.S.S groups. BMIz decreased significantly for boys (-0.11 [95% CI, -0.13 to -0.08]; p < 0.0001) and girls (-0.05 [-0.08 to -0.03]; p < 0.0001). No equivalence between LA.S.S and A.S groups was evidenced. For girls, the trend to superiority for LA.S.S was confirmed by the more favourable change (-0.06 [-0.11 to -0.01]; p = 0.01) observed on superiority analysis, with no differential change for boys (0.02 [-0.03 to 0.08]; p = 0.41).

CONCLUSIONS

A public health school-based intervention using the proportionate universalism principle may be effective in not worsening or even reducing overweight social inequalities in adolescents, especially for girls. Overcoming social barriers may help health professionals dealing with the burden and inequalities of overweight in adolescents.

Anthropometric prediction of DXA-measured body composition in female team handball players

Background

The relevance of body composition (BC) to performance in sport has long been appreciated with special concern on the total and regional proportion of fat and muscle. Dual-energy X-ray absorptiometry (DXA) is able to accurately measure BC, but it may not be easily available in practice; anthropometry has long been used as a simple and inexpensive field method to objectively assess BC. The aim of this study was twofold: first, to develop and validate a sport-specific anthropometric predictive equation for total body fat mass (FM) and lean mass components in female handball players to be used in the sport setting; second, to cross-validate in female team handball players several independently developed, predictive equations for BC in female athletes.

Methods

A total of 85 female team handball players (30 wings, 31 backs, 14 pivots, 10 goalkeepers) of different competitive levels underwent anthropometry and a whole-body DXA scan. Multiple linear regression analysis was used to develop predictive equations in a derivation sample (n = 60) of randomly selected players using demographic and anthropometric variables. The developed equations were used to predict DXA outcomes in an independent validation sample (n = 25).

Results

Statistically significant (P < 0.001) models were developed for total body FM (adjusted R² = 0.943, standard error of the estimate, SEE = 1,379 g), percentage FM (adjusted R² = 0.877, SEE = 2.00%), fat-free soft tissue mass (FFSTM) (adjusted R² = 0.834, SEE = 2,412 g), fat-free mass (FFSTM + bone mineral content; adjusted R² = 0.829, SEE = 2,579 g). All models were robust to collinearity. Each developed equation was successfully validated in the remaining 25 players using correlation analysis, mean signed difference, t-test, and Bland–Altman plot. The whole dataset of team handball players (n = 85) was used to cross-validate several predictive equations independently developed by others in female athletes. Equations significantly (P < 0.001 for all; t-test) over- or underestimated the corresponding DXA measurements.

Discussion

It is concluded that in team female handball players the anthropometric equations presented herein are able to estimate body fat and FFSTM with accuracy. Several BC predictive anthropometric equations developed in different female athletic populations revealed inaccurate when tested in team handball players. These results should be of use for coaches, physical trainers, and nutritionists when evaluating the physical status of female team handball players.