Defining health-related obesity in prepubertal children

Effect of Sleep Restriction on Adolescent Cognition by Adiposity: A Randomized Crossover Trial

Importance

Pediatric obesity is associated with impaired cognitive function; however, the mechanisms underlying this association demand assessment. Sleep may be a relevant moderator, as poor sleep predicts both increased adiposity and impaired cognitive function.

Objective

To determine the effects of adiposity and sleep on adolescent cognitive function.

Design, Setting, and Participants

This single-blind randomized crossover trial was conducted from September 2020 to October 2022. Parents or caregivers provided demographic information for adolescent participants. Body mass index percentile and bioelectrical impedance analysis assessed adiposity. Adolescents completed 2 actigraphy-confirmed sleep conditions, adequate and restricted, followed by in-person cognitive assessment. No additional follow-up was provided. Data collection for this population-based study took place in a behavioral medicine clinic in Birmingham, Alabama. A total of 323 participants were assessed for eligibility (ages 14-19 years and healthy). Of the 244 eligible adolescents, 157 declined participation. Eighty-seven were randomized and 26 dropped out postenrollment. The final sample included 61 adolescents, 31 with healthy weight and 30 with overweight or obesity. Data were analyzed from April to October 2023.

Interventions

Following a 2-day washout period of adequate sleep, adolescents completed 2 sleep conditions: adequate (mean [SD] duration, 8 hours, 54 minutes [58.0 minutes]) and restricted (mean [SD] duration, 4 hours, 12 minutes [50.7 minutes]).

Main Outcomes and Measures

The National Institutes of Health Cognitive Toolbox assessed global and fluid cognition, cognitive flexibility, working and episodic memory, attention, and processing speed. The Stroop Task assessed inhibition.

Results

The final sample included 61 adolescents (mean [SD] age, 16.3 [1.6] years; 35 [57.4%] female). Restricted sleep predicted poorer global cognition scores (restricted mean [SD], 98.0 [2.8]; adequate mean [SD], 103.2 [2.9]), fluid cognition scores (restricted mean [SD], 94.5 [3.2]; adequate mean [SD], 102.0 [3.6]), and cognitive flexibility scores (restricted mean [SD], 84.8 [3.0]; adequate mean [SD], 92.8 [3.0]) for adolescents with overweight or obesity. No differences emerged for adolescents with healthy weight. Adolescents with overweight or obesity also had poorer attention scores (mean [SD], 80.0 [2.3]) compared to adolescents with healthy weight (mean [SD], 88.4 [SD, 2.3]) following restricted sleep. No differences emerged following adequate sleep. Findings were similar for total body fat percentage (TBF%); however, for adolescents with TBF% above 42, restricted sleep also predicted poorer processing speed, and the association between sleep and attention did not vary based on TBF%.

Conclusions and Relevance

Adolescents with overweight or obesity may be more vulnerable to negative cognitive effects following sleep restriction. Improved sleep hygiene and duration in this group may positively impact their cognitive health.

Trial Registration

ClinicalTrials.gov Identifier: NCT04346433.

Metabolic risk factors in prepubertal and pubertal patients with overweight and obesity

OBJECTIVES

Metabolic syndrome (MetS) is a cluster of conditions linked to obesity that increases cardiovascular risk. We evaluated the frequency of clinical abnormalities associated with overweight and obesity in childhood, to determine whether a diagnosis of MetS is appropriate in this population.

METHODS

Cross-sectional study with 116 pubertal and prepubertal children with a mean age (SD) of 10.9 (2.5) years, with overweight and obesity. We defined MetS using the International Diabetes Federation criteria, regardless of the age.

RESULTS

45 patients met the criteria, 20 had at least one metabolic abnormality in addition to a high waist circumference (WC), and seven with WC below percentile 90th, had at least one metabolic abnormality. The prepubertal had higher zBMI [3.1 (2.6-3.8) vs. 2.8 (2.4-3.3); p=0.037], less lean body mass (kg) [27.13 (7.3) vs. 34.13 (9.8); p=0.005] and a similar frequency of non-alcoholic fatty liver disease (NAFLD) compared to the pubertal [44.7 vs. 35.9; p=0.323]. Prepubertal with NAFLD had higher zBMI, lower HDL levels, higher TG/HDL ratios and higher fat percentages; while pubertal with NAFLD had higher WC/height, aspartate aminotransferase and oxaloacetic transaminase.

CONCLUSIONS

The diagnosis of MetS in childhood is not fundamental. Individualized management, focusing on the earliest age groups, in which we identified a more severe degree of obesity, should be done. We also recommend screening for NAFLD in all ages, due to the high prevalence observed.

Knowledge, Attitude and Practices of Sugar-Sweetened Beverages: A Cross-Sectional Study among Adolescents in Selangor, Malaysia

This study aims to examine the level of knowledge, attitude and practices (KAP) of adolescents towards sugar-sweetened beverages (SSB), together with the associated factors that determine their KAP. Data were collected using self-administered questionnaires that consisted of sociodemographic, the KAP for the SSB questionnaire, and the Beverage Intake Questionnaire (BEVQ). The respondents’ heights, weights, waist circumferences and body fat percentages were measured. This study involved 439 adolescents aged between 13 and 17 years old, in public secondary schools in Selangor, Malaysia. The results reveal that 35% of the adolescents were overweight, 26% had a high waist circumference, and 45% had a high body fat percentage. Caffeinated drinks and full cream milk were the most frequently consumed SSBs. The KAP score revealed a good attitude (88.4%), a moderate knowledge (51.8%) and a poor practice (40.5%). Those with a higher body fat percentage showed significantly good attitude scores (p < 0.05). Low household income groups, females, adolescents aged 16–17 years old and being from an urban area demonstrated a significant (p < 0.05) positive determinant towards the KAP score. In conclusion, high awareness of negative health outcomes associated with SSBs among adolescents was not in accordance with the level of their lifestyle choices.

Associations between appetitive traits, dietary patterns and weight status of children attending the School Kids Intervention Program

BACKGROUND

The nexus between appetitive traits, dietary patterns and weight status has predominantly been studied in a mixed sample (healthy weight, overweight and obese sample).

AIM

This cross-sectional study examined associations between overweight/obese children's appetitive traits, dietary patterns and weight status.

METHODS

We studied children (N = 58, body mass index z-score: 2.25±0.46), 4-12 years attending the School Kids Intervention Program. Children's appetitive traits and dietary patterns were measured with the Child Eating Behaviour Questionnaire and Children's Dietary Questionnaire, respectively. Children's height and weight were used to compute body mass index z-score; waist circumference was also measured and waist-to-height ratio was calculated.

RESULTS

After controlling for children's age and gender, hierarchical linear regression analyses showed that lower scores for slowness in eating were associated with higher body mass index z-scores in children (β = -0.31, p = 0.01). Higher scores for emotional overeating were associated with higher waist-to-height ratio in children (β = 0.48, p = 0.01). Higher scores for fussiness were correlated with lower scores for fruits and vegetables (β = -0.59, p < 0.001) and higher scores for non-core foods (β = 0.26, p = 0.04).

CONCLUSION

Results observed in the current sample of overweight and obese children are consistent with previous studies examining healthy-weight children. Slowness in eating may foster an obesity 'protective' effect, whereas emotional overeating may promote susceptibility to weight gain. Fussy eating may impair diet quality by lower consumption of vegetables and fruits and higher intake of non-core foods. This evidence will support dietitians to consider children's appetitive traits when providing dietary consultation to support obesity management among overweight/obese children.

Metabolic Syndrome and Insulin Resistance in Schoolchildren From a Developing Country

Background: Overweight and obesity are prevalent in schoolchildren due to dietary habits and lack of exercise. These children are prone to metabolic syndrome (MS) and future risk of type 2 diabetes mellitus and cardiovascular diseases. Materials and Methods: This cross-sectional study was conducted in Bhubaneswar City, Eastern India, among schoolchildren. Obesity and overweight were determined by the Indian Academy of Pediatrics guideline. Fasting venous blood samples were taken for insulin, blood glucose, and lipid levels measurement. Blood pressure was measured as per the protocol. The International Diabetic Federation (IDF) criteria for the definition of MS were followed. Insulin resistance was determined by a homeostatic model assessment (HOMA-IR). Results: A total of 1,930 children were screened, of which 545 (28.2%) were overweight and obese. The male to female ratio was 1.27. The overall prevalence of MS was 21.8% (11% in 6 to ≤10 years old and 30.6% in 11 to 16 years old). A history of cardiovascular disease, diabetes, obesity, and hypertension in the family was present in 42.7%. Acanthosis nigricans was present in 46.4%. A history of exclusive breast feeding for 6 months was present in 68.1%. The mean HOMA-IR in children with MS was 5.46 compared to 2.18 in those without MS (insulin resistance was more common in children with MS). Conclusions: The present study found a higher prevalence of MS and insulin resistance in schoolchildren from Eastern India who are overweight/obese.

Adiposity Criteria in Assessing Increased Cardiometabolic Risk in Prepubertal Children

Objective: Adiposity induces the clustering of cardiometabolic risk factors, and pediatric adiposity is a better indicator for adulthood cardiometabolic diseases than pediatric metabolic syndrome. However, the observed prevalence of pediatric adiposity depends on the methods and cut-points used. Therefore, we aimed to define diagnostic criteria for adiposity which enable more valid identification of prepubertal children at increased cardiometabolic risk. Methods: The participants were 470 prepubertal children (249 boys) aged 6-8 years. The measures of adiposity included body mass index-standard deviation score (BMI-SDS), waist-to-height ratio (WHtR) and body fat percentage (BF%) assessed by bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA). Criteria for adiposity were determined by increased cardiometabolic risk. Cardiometabolic risk factors which correlated with BF% assessed by DXA in the upper but not lower half of BF% (serum insulin and plasma high-density lipoprotein cholesterol, triglycerides, gamma-glutamyl transferase, high-sensitivity C-reactive protein and uric acid) were included in the cardiometabolic risk score (CMS). We computed receiver operating characteristics curves for the measures of adiposity using the ≥90th percentile of CMS as a measure of increased cardiometabolic risk, and local regression curves were graphed to demonstrate the associations of the measures of adiposity with CMS. Results: In girls, WHtR of 0.445 (area under curve 0.778, its 95% confidence interval 0.65-0.91, sensitivity and specificity 0.73) and BF% of 19.5% assessed by BIA (0.801, 0.70-0.90, 0.73) were the best overall criteria for increased cardiometabolic risk. In boys, BMI-SDS of 0.48 (0.833, 0.75-0.92, 0.76) was the best overall criterion for increased cardiometabolic risk. While local regression curves in girls showed that WHtR of 0.445 corresponds well to a point where CMS began to increase, in boys local regression curves suggest that CMS began to increase even at a lower level of BMI-SDS than 0.48. Moreover, the diagnostic ability of the measures of adiposity to exclude increased cardiometabolic risk was poorer than the ability to detect it. Conclusions: In general, the measures of adiposity have sufficient diagnostic accuracy to be utilized as the screening tool for increased cardiometabolic risk. The observed cut-points for adiposity were lower than the traditional cut-points for adiposity.

Overweight and Perceived Health in Mexican American Children: A Pilot Study in a Central Texas Community

This study assessed actual and perceived health status of overweight Mexican American clients at a central Texas school-based health center in a predominately Hispanic school district. It also explored the participants’ interest in making lifestyle changes to promote a healthy weight. A medical records review indicated that of the Hispanic children between the ages of 7 and 12 years, 38% had a weight status at or above the 85th percentile. Assessments were conducted in a sample of these overweight Mexican American children to learn about their medical history, eating and activity patterns, perceived health and body size, and general health-risk status. Weight-related conditions, such as elevated blood pressure and cholesterol levels, were found in more than half the sample. Few consumed fruits and vegetables, and many engaged in only sedentary activities. The majority perceived themselves as “big,” wanted to make changes in their body size, and wanted family members to participate in making changes with them. Although most of the sample were in the 97th body mass index percentile, many perceived themselves to be as healthy as or healthier than others. These findings substantiate the need to design and implement a culturally appropriate weight management and obesity prevention program in this community. However, the perception of being healthy in the presence of multiple indicators of poor health may pose challenges to successful intervention.

Anthropometric Profile, Serum Leptin, Antioxidant Vitamins, LEPR Q223R Polymorphism and Cardiovascular Risk Factors in Adolescents

Cardiovascular disease (CVD) risk factors, such as bad eating habits, are typical in adolescence and lead to the consumption of meals that are not always sufficient in vitamins A, E, β-carotene, excess calories and elevated serum leptin levels. The purpose of this research is to study the relationship between vitamin A deficiency (VAD), β-carotene deficiency (βcD), vitamin E deficiency (VED) and to explore the association of leptin receptor Q223R polymorphisms with obesity and other risk factors for CVD. Method: This observational study included 237 adolescents recruited from Adolescents Reference Center, Brazil. It was collected: socioeconomic and clinical data, laboratory and molecular samples. Results: The average age was 14.93 ± 2.18 years, 66.2 % were girls, 38.0 % had high levels of total cholesterol (TC) between 10-14 years Triceps (TSF) and subscapular skinfolds (SSF) measurements were inversely correlated with VAD. There was also an association between VAD, βcD and high triglyceride (TG) levels. Adolescents with the RR genotype presented a trend toward higher levels of body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), TC, TG, low density lipoprotein (LDLC), leptin and low levels of high-density lipoprotein (HDL-c). Conclusion: The girls had higher levels of leptin than boys. Abdominal fat, βcD and VED were observed in adolescents with VAD. Individuals with RR genotype have drawn attention to cardiovascular risk factors such as high rate of LDLC and reduced rate of HDLc. Thus, it is possible that individuals with this genotype may be more susceptible to the presence of cardiovascular risk factors.

Low Diagnostic Accuracy of Body Mass Index-Based and Waist Circumference-Based References of Childhood Overweight and Obesity in Identifying Overfat among Chinese Children and Adolescents

This study aimed to investigate the diagnostic accuracy of body mass index- (BMI-) based and waist circumference- (WC-) based references for childhood overweight and obesity in screening overfat individuals among 2134 Chinese children and adolescents. In this study, overfat status was defined as over 25% body fat for boys and over 30% for girls. Childhood obesity or overweight was defined by four BMI-based references and two WC-based references. All BMI-based references for obesity showed low sensitivity (SE) (0.128–0.473) but high specificity (SP) (0.971–0.998) in detecting overfat individuals in the current population. SE values increased from 0.493 to 0.881 when BMI- and WC-based references for overweight were used to detect overfat individuals. All references for overweight showed high SP rates (0.816–0.966). To improve diagnostic accuracy for childhood obesity, further studies may define a cut-off value for childhood obesity specific for a local population and ethnicity by using health-related overfat data.

Waist-to-height ratio and sedentary lifestyle as predictors of metabolic syndrome in children in Ecuador

OBJECTIVE

To determine the predictors and prevalence of metabolic syndrome (MS) and the presence of vascular inflammation in apparently-normal children (10-15 years) of both sexes in Guayaquil, Ecuador.

STUDY DESIGN AND METHODS

We included 395 apparently-healthy students from a middle-income school in a cross-sectional survey. Informed consent was obtained from students and parents. Anthropometric measurements including blood pressure (BP), body mass index (BMI) and waist-to-height ratio (WHtR), and blood tests were recorded. Vascular inflammation parameters were assessed. Percentiles of the different parameters were used, and MS was defined according to National Cholesterol Education Program Adult Treatment Panel III criteria (NCEP-ATPIII). Waist circumference>P 75, blood pressure>P 90, glucose>100mg/dl, triglycerides>100mg/dl, HDL<45mg/dl. If 3 of the 5 criteria were present, this was considered MS.

RESULTS

The mean age was 12 years (186 boys, 209 girls). The overall prevalence of MS was 9.37% (6.33% in girls, 3.04% in boys). Sustained hypertension was detected in 6.6% of children and pre-hypertension in 7.1%. Obesity was found in 1.8% of subjects, and overweight in 15.2%. Triglycerides has a RR 2.34 (1.97-2.76); HOMA index has a RR 1.97(1.62-2.40); HDL cholesterol has a RR 1.84(1.58-2.13); Insulin level has a RR 1.53(1.40-1.67) and interleukin 6 has RR 1.83(1.20-2.79). Serum glucose, total cholesterol and LDL-Cholesterol had no association with the metabolic syndrome. HDL-Cholesterol<45mg/dl and triglyceride>100mg/dl were present in 70% of subjects with MS. The WHtR threshold≥0.5 was 100% sensitive in both sexes (67% specificity in boys and 69% in girls). There were significant associations between the WHtR and pre-hypertension and sedentary lifestyle (P<0.001 and P<0.003 respectively). A WHtR value of ≥0.50 indicated a 2.2-fold increased risk of MS compared with normal WHtR, and normal weight.

CONCLUSIONS

A WHtR≥0.5 was 100% sensitive in detecting MS in 10-15 year-old boys and girls in the normal or overweight range of the BMI. This assessment is a simple and practical tool for use in population-based studies of cardiovascular risk. When combined with pre-hypertension and a sedentary lifestyle, the WHtR is highly sensitive in predicting MS.

The Identification of a Threshold of Long Work Hours for Predicting Elevated Risks of Adverse Health Outcomes

Working long hours has been associated with adverse health outcomes. However, a definition of long work hours relative to adverse health risk has not been established. Repeated measures of work hours among approximately 2,000 participants from the Panel Study of Income Dynamics (1986-2011), conducted in the United States, were retrospectively analyzed to derive statistically optimized cutpoints of long work hours that best predicted three health outcomes. Work-hours cutpoints were assessed for model fit, calibration, and discrimination separately for the outcomes of poor self-reported general health, incident cardiovascular disease, and incident cancer. For each outcome, the work-hours threshold that best predicted increased risk was 52 hours per week or more for a minimum of 10 years. Workers exposed at this level had a higher risk of poor self-reported general health (relative risk (RR) = 1.28; 95% confidence interval (CI): 1.06, 1.53), cardiovascular disease (RR = 1.42; 95% CI: 1.24, 1.63), and cancer (RR = 1.62; 95% CI: 1.22, 2.17) compared with those working 35-51 hours per week for the same duration. This study provides the first health risk-based definition of long work hours. Further examination of the predictive power of this cutpoint on other health outcomes and in other study populations is needed.

The role of TGF-β1 869 T > C and PPAR γ2 34 C > G polymorphisms, fat mass, and anthropometric characteristics in predicting childhood obesity at birth: A cross-sectional study according the parental characteristics and newborn's risk for child obesity (the newborns obesity's risk) NOR study

This study proposed to establish a correlation between the risk score for child obesity and anthropometric, genetic, and bioimpedance characteristics in mothers and newborns, and to assess the discriminant ability for anthropometric parameters to classify over-fatness (defined by bioimpedance body fatness %) in pregnant women.We performed a cross-sectional study on 388 couples (mother and father) and their newborns admitted in a Tertiary Hospital from Romania. The measured parameters for mothers and their newborns were risk percentage for child obesity, anthropometric characteristics (mid-upper arm circumference [MUAC], tricipital skinfold thickness [TST] of mother and newborn), genetic polymorphisms (human peroxisome proliferator-activated receptor γ [PPARγ2] 34 C > G and transforming growth factor-beta 1 [TGF-β1] 869 T > C gene polymorphisms in both mothers and newborns), and mother's bioimpedance characteristics (fat mass [FM] %).The obesity risk score according to standard predictable Northern Finland Birth Cohort equation was in our study 4.07%. We found a monotone positive significant correlation between the newborn's risk of childhood obesity and the mother's TST (P = 0.01), as well as a tendency toward statistical significance concerning correlation with mother's MUAC (P = 0.053), without any correlations with the mothers' bioimpedance parameters and also a positive correlation between the newborn's risk of childhood obesity and the newborn's anthropometrical characteristics like body mass index (BMI), MUAC, and TST (P < 0.001). We observed that the calculated newborn's risk percentage for child obesity was greater for the variant allele of the TGF-β1 869 T > C polymorphism and also for the wild-type C allele of the PPARγ2 34 C > G gene polymorphism. Our study indicated that the best predictors for over-fatness are BMI and MUAC (P = 0.01 < 0.02 and P = 0.019 < 0.02, respectively).

High Discrepancy in Abdominal Obesity Prevalence According to Different Waist Circumference Cut-Offs and Measurement Methods in Children: Need for Age-Risk-Weighted Standardized Cut-Offs?

Background

Waist circumference (WC) is a good proxy measure of central adiposity. Due to the multiplicity of existing WC cut-offs and different measurement methods, the decision to use one rather than another WC chart may lead to different prevalence estimates of abdominal obesity in the same population. Aim of our study was to assess how much the prevalence of abdominal obesity varies in Italian schoolchildren using the different available WC cut-offs.

Methods

We measured WC at just above the uppermost lateral border of the right ilium in 1062 Italian schoolchildren aged 7–14 years, 499 living in Northern Italy and 563 in Southern Italy. Abdominal obesity was defined as WC ≥90^th percentile for gender and age according to nine WC charts.

Results

We found an extremely high variability in the prevalence of abdominal obesity detected in our study-populations according to the different WC charts, ranging in the overall group from 9.1% to 61.4%. In Northern Italy children it varied from 2.4% to 35.7%, and in Southern ones from 15.1% to 84.2%.

Conclusions

On the basis of the chosen WC cut-offs the prevalence of abdominal obesity varies widely, because percentile-charts are strongly influenced by the population status in a particular moment. A further rate of variability may lay on the site of WC measurement and on the statistical method used to calculate WC cut-offs. Risk-weighted WC cut-offs measured in a standardized anatomic site and calculated by the appropriate method are needed to simply identify by WC measurement those children at high risk of cardio-metabolic complications to whom specific and prompt health interventions should be addressed.

Deuterium oxide dilution and body composition in overweight and obese schoolchildren aged 6-9 years

OBJECTIVE

To correlate different methods of body composition assessment in overweight or obese schoolchildren, using deuterium oxide (D2O) dilution as a reference.

METHODS

Percentage of total body water (%TBW), fat free mass (%FFM), and body fat (%BF) were assessed by D2O and tetrapolar electrical bioimpedance analysis (BIA) in 54 obese and overweight students aged 6-9 years. Skinfold thickness (ST), body mass index (BMI), conicity index (CI), waist circumference (WC), waist-to-height ratio (WHtR), and waist-to-hip (WHR) ratio were also used.

RESULTS

Mean values for body composition were 38.4%±8.4% BF, 44.9%±6.1% TBW and 61.6%±8.4% FFM. There was no significant difference in body weight, body fat mass (FM), TBW, and FFM between genders. Regarding D2O, ST underestimated %BF, and overestimated %FFM in both genders (p<0.05). BIA overestimated %TBW in the group as a whole and in males (p<0.05). The only positive and strong correlations occurred in females regarding the WC (σ=0.679), CI (r=0.634), and WHtR (r=0.666).

CONCLUSIONS

In this sample of obese and overweight children, there were strong correlations between body composition measured by D2O and some indices and anthropometric indicators in females, but there was no positive and strong correlation of fat tissue with the indices/indicators at all ages and in both genders.

Exploratory Study Examining Clinical Measures of Adiposity Risk for Predicting Obesity in Adolescents with Physical Disabilities

OBJECTIVE

The purposes of this study were to assess the accuracy of clinical measures for predicting adiposity when compared with a criterion standard of body fat percentage measured by dual-energy X-ray absorptiometry and to determine the most appropriate cut points for classifying obesity for each measure in adolescents with physical disability.

DESIGN

Body mass index, triceps skinfolds, and waist, arm, and leg circumferences were collected on 29 adolescents aged 14-17 yrs with spinal cord injury, cerebral palsy, or spina bifida. Percentage of body fat was measured using dual-energy X-ray absorptiometry. Multiple linear regression models were used to assess the ability of measures to predict percentage of body fat. Receiver operating characteristic curves were used to identify optimal cut points for each measure.

RESULTS

Although all clinical measures correlated with body fat as measured by dual-energy X-ray absorptiometry, current cut points are not adequate in this group. Using a body mass index of 20 kg/m (boys) and 19 kg/m (girls) was optimal but still misclassified a significant number of participants as nonobese in this group. Using the optimal cut points for waist circumference, which were 83 cm (boys) and 78 cm (girls), was the best predictor.

CONCLUSIONS

Body mass index, triceps skinfolds, and waist, leg, and arm circumferences are valid measures for estimating obesity in adolescents with physical disability, but further research is needed to validate disability-specific cut points.

A primary care intervention to improve weight in obese children: A feasibility study

PURPOSE

Examine the effects of a primary care weight management program, which used a parent-child-provider collaborative negotiation intervention, among rural-dwelling families with obese children.

DATA SOURCES

Health histories, physical examinations, fasting blood samples, interviews, and questionnaires.

CONCLUSIONS

Feasibility of implementing a family weight management intervention in a rural primary care setting was demonstrated. Few differences between the treatment and comparison groups were found; however, more favorable trends and outcomes occurred in those who received the intervention.

IMPLICATIONS FOR PRACTICE

Positive provider-patient communication in helping families with obese children make difficult lifestyle changes should be encouraged in primary care clinics as small changes in behavior can result in reducing risk and improving health outcomes.

Youth overweight and metabolic disturbances in predicting carotid intima-media thickness, type 2 diabetes, and metabolic syndrome in adulthood: the Cardiovascular Risk in Young Finns study

OBJECTIVE

Our objective was to assess cardiovascular risk and metabolic complications in adulthood in subjects with or without overweight and metabolic disturbances (i.e., elevated blood pressure, glucose, triglycerides, low HDL cholesterol, and high LDL cholesterol) and their combinations as youth.

RESEARCH DESIGN AND METHODS

Using data from the population-based Cardiovascular Risk in Young Finns study, we examined the utility of four age- and sex-specific youth phenotypes (group I: normal weight, no metabolic disturbances; group II: normal weight, one or more metabolic disturbances; group III: overweight/obese, no metabolic disturbances; group IV: overweight/obese, one or more metabolic disturbances) in predicting adult high carotid intima-media thickness (IMT), type 2 diabetes mellitus (T2DM), and metabolic syndrome (MetS). The study included 1,617 participants 9-24 years of age at baseline who were followed up 21-25 years later.

RESULTS

IMT (mean ± SEM) was higher among participants in groups II (0.627 ± 0.005 mm, P = 0.05), III (0.647 ± 0.010 mm, P = 0.005), and IV (0.670 ± 0.010 mm, P < 0.0001) compared with group I (0.616 ± 0.003 mm). In addition, subjects in group IV had significantly higher IMT compared with those in group II (P = 0.002). Participants in groups II, III, and IV were at increased risk of the development of MetS in adulthood compared with those in the control group. For group II participants, the difference was attenuated after risk factor adjustments. Additionally, participants in group III and IV were at increased risk of the development of T2DM compared with those in groups I and II.

CONCLUSIONS

While metabolic risk factors associated with overweight increase future risk for MetS, T2DM, and increased IMT, overweight in isolation is also a risk factor. Therefore, overweight should be prevented and treated wherever possible.

Validation of a BMI cut-off point to predict an adverse cardiometabolic profile with adiposity measurements by dual-energy X-ray absorptiometry in Guatemalan children

OBJECTIVE

To identify a body fat percentage (%BF) threshold related to an adverse cardiometabolic profile and its surrogate BMI cut-off point.

DESIGN

Cross-sectional study.

SETTING

Two public schools in poor urban areas on the outskirts of Guatemala City.

SUBJECTS

A convenience sample of ninety-three healthy, prepubertal, Ladino children (aged 7-12 years).

RESULTS

Spearman correlations of cardiometabolic parameters were higher with %BF than with BMI-for-age Z-score. BMI-for-age Z-score and %BF were highly correlated (r=0·84). The %BF threshold that maximized sensitivity and specificity for predicting an adverse cardiometabolic profile (elevated homeostasis model assessment-insulin resistance index and/or total cholesterol:HDL-cholesterol ratio) according to receiver operating characteristic curve analysis was 36 %. The BMI-for-age Z-score cut-off point that maximized the prediction of BF ≥ 36 % by the same procedure was 1·5. The area under the curve (AUC) for %BF and for BMI data showed excellent accuracy to predict an adverse cardiometabolic profile (AUC 0·93 (sd 0·04)) and excess adiposity (AUC 0·95 (sd 0·02)).

CONCLUSIONS

Since BMI standards have limitations in screening for adiposity, specific cut-off points based on ethnic-/sex- and age-specific %BF thresholds are needed to better predict an adverse cardiometabolic profile.

Prevalence of obesity and motor performance capabilities in Tyrolean preschool children

BACKGROUND

The childrens' world of movement has changed dramatically during the last decades. As a consequence motor performance decreases particularly in children affected by overweight and obesity. This study analyses the influence of the body mass index (BMI) on motor performance of pre-school children.

METHODS

In a cross-sectional study including 41 kindergartens in Tyrol (Austria), 4- to 5-year-old children (n = 1,063) were recruited. Four BMI groups were used according to a German BMI reference system: Group I (anorexic/underweight), group II (normal weight), group III (overweight) and group IV (obese). Motor performance was assessed by the use of the Karlsruhe Motorik-Screening (KMS 3-6).

RESULTS

Out of the 1,063 preschool children (550 ♂, 513 ♀) 7.6 % (n = 81) were overweight and 5.5 % (n = 58) were obese. The results demonstrate that motor performance of under- and overweight preschool-children is not different from children with normal BMI, but obese children had significantly lower motor performance (p < 0.001).

CONCLUSION

The prevalence of overweight and obese Tyrolean preschool children is similar to those of non-mountainous areas of Austria and Germany. The fact that motor performance is reduced only in obese children suggests that targeted promotion of physical activity is urgently needed for preschool children particularly considering children with a risk to develop obesity. Besides the efforts of parents, nursery schools are the ideal setting for intervention measures.

Elevated remnant lipoproteins may increase subclinical CVD risk in pre-pubertal children with obesity: a case-control study

OBJECTIVES

Current clinical guidelines to assess paediatric cardiovascular disease (CVD) risk heavily rely on cholesterol parameters that are generally normal for obese children. Remnant lipoproteins have emerged as a critical CVD risk factor particularly in adults with normolipidemia. We assessed remnant lipoprotein concentration (measured by apolipoprotein [apo] B48) and its relationship with other traditional CVD risk biomarkers in pre-pubertal children with obesity.

METHODS

Pre-pubertal children (n = 78) with obesity (n = 39, 9.9 ± 0.3 years old) as well as sex-matched normal-weight controls (n = 39, 9.8 ± 0.3 years) were assessed for anthropometry, blood pressure and fasting plasma biochemical parameters for remnant lipoprotein, lipid and glucose/insulin metabolism, and inflammatory status.

RESULTS

Children with obesity had striking 2-fold higher apoB48-containing remnant lipoproteins concentrations relative to normal-weight peers; the magnitude of elevation in the remnant lipoproteins is comparable to the levels previously reported for adults with established CVD and type-2 diabetes. Fasting apoB48 was positively correlated with fasting triglyceride concentration in children with obesity (r = 0.51, P < 0.001) and their normal-weight peers (r = 0.45, P < 0.01). Traditional CVD biomarkers including low-density lipoprotein cholesterol showed no difference between groups and remained within the normal range for a paediatric population.

CONCLUSION

Elevated apoB48-containing remnant lipoprotein is a stronger biomarker for paediatric CVD risk compared to traditional cholesterol parameters and may be associated with early adaptation of the intestine during obesity. Further investigation of abnormalities associated with the secretion and/or clearance of atherogenic remnant lipoproteins during the postprandial state may yield insight into our understanding of and therapeutic targets for managing risk for CVD in children with obesity.

Educational interventions in childhood obesity: a systematic review with meta-analysis of randomized clinical trials

OBJECTIVE

To assess the effectiveness of educational interventions including behavioral modification, nutrition and physical activity to prevent or treat childhood obesity through a systematic review and meta-analysis of randomized trials.

METHOD

A search of databases (PubMed, EMBASE and Cochrane CENTRAL) and references of published studies (from inception until May 2012) was conducted. Eligible studies were randomized trials enrolling children 6 to 12 years old and assessing the impact of educational interventions during 6 months or longer on waist circumference, body mass index (BMI), blood pressure and lipid profile to prevent or treat childhood obesity. Calculations were performed using a random effects method and pooled-effect estimates were obtained using the final values.

RESULTS

Of 22.852 articles retrieved, 26 trials (23.617 participants) were included. There were no differences in outcomes assessed in prevention studies. However, in treatment studies, educational interventions were associated with a significant reduction in waist circumference [-3.21 cm (95%CI -6.34, -0.07)], BMI [-0.86 kg/m(2) (95%CI -1.59, -0.14)] and diastolic blood pressure [-3.68 mmHg (95%CI -5.48, -1.88)].

CONCLUSIONS

Educational interventions are effective in treatment, but not prevention, of childhood obesity and its consequences.

Nutritional status in mentally disabled children and adolescents: A study from Western Turkey

OBJECTIVE

To assess the nutritional status of mentally disabled children in Turkey on the basis of anthropometric indicators and dietary intake.

METHODOLOGY

The sample of the study consisted of 77 mentally disabled children with ages between 10 and 18 years. The body mass index and body fat ratios of the children were calculated by measuring their body weight, height, and the skinfold thickness of their triceps and subscapular. Their three-day nutrition consumption was recorded in order to determine their nutrient intake.

RESULTS

When the body weights of the children were evaluated according to their ages, 14.3% of the children were found to be thin. The shortness rate among the participants was 28.6%. The shortness ratio was found to increase with age and girls had a higher inclination for shortness than boys. The ratios of those with ≤5(th) percentile upper middle arm circumference were 32.7% in the 10-13 age group, and 36.0% in the 14-18 age group. The folic acid and calcium intakes of girls in the 10-13 age group, and the calcium intakes of boys in the 10-13 age group were under the suggested values. In the 14-18 age group the vit C and calcium intakes of girls and the calcium intakes of boys were under the recommended values.

CONCLUSIONS

The prevalence of malnutrition is high among mentally disabled children. In order to raise their quality of life, mentally disabled children must be provided with sufficient nutritional support.

Waist circumference-to-height ratio predicts adiposity better than body mass index in children and adolescents

OBJECTIVE

Body mass index (BMI) is the surrogate measure of adiposity most commonly employed in children and adults. Waist circumference (WC) and the waist circumference-to-height ratio (WCHt) have been proposed as markers of adiposity-related morbidity in children. However, no study to date has compared WCHt, WC, BMI and skinfolds thickness for their ability to detect body adiposity.

AIM

To compare WCHt, WC, BMI and skinfolds for their accuracy in predicting percent body fat (PBF), percent trunk fat (PTF) and fat mass index (FMI) in a large sample of children and adolescents.

DESIGN, SETTING AND PARTICIPANTS

We studied 2339 children and adolescents aged 8-18 years from the US National Health and Nutrition Examination Survey 2003/2004. Body fat was measured using dual-energy X-ray absorptiometry. Multivariable regression splines were used to model the association between PBF, PTF, FMI and the predictors of interest.

RESULTS

WCHt alone explained 64% of PBF variance as compared with 31% for WC, 32% for BMI and 72% for the sum of triceps and subscapular skinfolds (SF2) (P<0.001 for all). When age and gender were added to the predictors, the explained variance increased to 80% for the WCHt model, 72% for the WC model, 68% for the BMI model and 84% for the SF2 model. There was no practical advantage to add the ethnic group as further predictor. Similar relationships were observed with PTF and FMI.

CONCLUSIONS

WCHt is better than WC and BMI at predicting adiposity in children and adolescents. It can be a useful surrogate of body adiposity when skinfold measurements are not available.

Relationship of body mass index and fitness levels among schoolchildren

Childhood obesity is an epidemic in the U.S.A., and understanding aspects of fitness is critical in implementing effective interventions. The purpose of this study was to analyze the relationship of obesity levels with the fitness levels of public school children in Louisiana. Over 7,000 school children participated in body mass index (BMI) and Fitnessgram® subtests including the Progressive Aerobic Cardiovascular Endurance Run (aerobic capacity), curl-ups, trunk lifts, push-ups (strength and endurance), and shoulder stretches (flexibility). The fitness measures and BMI were analyzed using chi-square and logistic regression to test for any significant relationships. The results indicated that the participants with healthy BMIs have the highest levels of physical fitness. The differences between the fitness levels of obese and healthy children were statistically significant. This study demonstrated a direct relationship between BMI status and fitness levels as measured by the Fitnessgram® among study participants. This finding is not exceedingly surprising, as common sense tells us that the heavier a person is, the less likely he or she is to be physically fit. However, this study is an important first step in understanding weight issues in children. This information can be used to develop data-driven interventions to assist children in becoming healthier and more physically fit.

A conative educational model for an intervention program in obese youth

BACKGROUND

Obesity in children has increased in recent years throughout the world and is associated with adverse health consequences. Early interventions, including appropriate pedagogy strategies, are important for a successful intervention program. The aim of this study was to assess changes in body mass index, the ability to perform sport activities, behavior in the classroom and academic performance following one year of a health-wellness intervention program in obese youth.

METHODS

The CEMHaVi program included 37 obese children (19 girls and 18 boys). Participants received an intervention program consisting of physical activity and health education. Assessment included body mass index, academic performance, classroom performance and ability to perform sport activities. Paired t tests were used to assess the effects of intervention, and chi square was used to assess inter-action between measures.

RESULTS

Findings of the study suggest significant decrease in Z scores of Body Mass Index and an improvement of academic performance, classroom behavior and the ability to perform sport activities (p < 0.05). Chi square testing showed significant positive inter-actions between body mass index, classroom behavior and academic performance.

CONCLUSIONS

Results following year one of CEMHaVi showed that a program of physical activity and health education had positive effects on obesity, behavior in the classroom and the ability to perform sport activities in obese adolescents. Significant inter-action in changes between variables was observed. Findings are important for designing intervention models to improve health in obese youth.

Waist circumference percentiles for Portuguese children and adolescents aged 10 to 18 years

The purposes of this study were to develop age- and sex-specific waist circumference reference data for Portuguese children and adolescents aged 10-18 years and to compare them with those from other countries. This was a school-based study performed in Portugal. A total of 22,003 children and adolescents aged 10-18 years were included in the study. Smoothed sex- and age-specific 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentile curves of waist circumference were estimated using Cole's lambda-mu-sigma method. Waist circumference values increased with age in both boys and girls, and boys had higher values than girls at every age and percentile. In both sexes, the Portuguese values in the 90th percentile were closer to the Bolivian values and considerably lower than those of the American children for all age groups.

CONCLUSION

The data presented provide information for abdominal risk assessment and clinical and lifestyle intervention; our results also provide useful baseline data information for the implementation of a surveillance system required to monitor trends and factors associated with abdominal obesity in children and adolescents.

Overweight status and intrauterine exposure to gestational diabetes are associated with children's metabolic health

BACKGROUND

Offspring of women with gestational diabetes (OGD) have greater risk for obesity and impaired metabolic health. Whether impaired metabolic health occurs in the absence of obesity is not clear.

OBJECTIVE

The purpose of this study was to investigate the independent and interactive effects of intrauterine exposure to gestational diabetes and of children's current weight status on their metabolic health.

METHODS

Children aged 5–10 years (n = 51) with and without intrauterine exposure to gestational diabetes (OGD vs. offspring of non-diabetic women [CTRL]) were grouped into normal weight (body mass index [BMI] < 85th %) and overweight (BMI > 85th %) according to Centers for Disease Control growth curves. Lipid profile was obtained by fasting blood draw, insulin sensitivity (SI) and secretion by liquid meal tolerance test, and body composition by dual-energy X-ray absorptiometry.

RESULTS

Despite similar average BMI percentiles among normal weight OGD versus CTRL, and overweight OGD vs. CTRL, OGD had greater total %fat and trunk fat adjusted for leg fat compared with CTRL (P < 0.05). Overweight children had lower SI (P < 0.05) and greater basal, static, and total insulin secretion independent of SI (P < 0.05). OGD was independently associated with greater static insulin secretion (P < 0.05) and the interaction between OGD and overweight was associated with greater basal insulin secretion independent of SI (P < 0.01). OGD and overweight were each associated with lower high-density lipoprotein-cholesterol (HDL-C) (P < 0.05).

CONCLUSION

Intrauterine exposure to gestational diabetes was associated with greater central adiposity and insulin secretion, and lower HDL-C, irrespective of current weight status. Future research should examine respective contributions of the intrauterine environment and of underlying genotype on children's metabolic health.

Body fat composition and occurrence of kidney stones in hypercalciuric children

In the last 10 years, the incidence of kidney stones has increased in the pediatric population, and this rise has been paralleled by a significant increase in pediatric obesity rates in the USA. The purpose of this study was to evaluate percentage body fat (%BF) measured by dual energy X-ray absorptiometry (DXA) in hypercalciuric children with and without kidney stones. A retrospective chart review was performed on children with idiopathic hypercalciuria based on a 24-h urine calcium excretion of >4 mg/kg/day or >200 mg/day who had undergone DXA scanning. Patients were then classified by sex and by %BF (3 categories; normal: <27% girls, <21% boys; at risk for obesity: 27-36% girls, 21-30% boys; obese: >36% girls, >30% boys). The 2003-2004 NHANES data were used as a control. Fifty patients (24 males) were analyzed, of whom 26% were assessed as having a normal %BF, 44% as being at risk for obesity, and 30% as being obese. Children with an increased %BF had a significantly higher occurrence of kidney stones (p = 0.03) than those with a normal %BF. No significant differences were noted in 24-h urine chemistries between the groups. In conclusion, an increased %BF was associated with an increased occurrence of kidney stones in children with idiopathic hypercalciuria.

Percent body fat and chronic disease risk factors in U.S. children and youth

BACKGROUND

The dramatic increase in pediatric obesity has renewed interest in accurate methods and screening indexes for identifying at-risk children and youth. Whether age-specific standards are needed is a factor that remains uncertain.

PURPOSE

This study was designed to describe the age-specific fatness-risk factor relationship in boys and girls across a wide age range.

METHODS

Data were from 12,279 white, black, and Mexican-American children and adolescents from the National Health and Nutritional Examination Surveys (NHANES) III (1998-1994) and IV (1999-2004). Children were grouped based on percent fat, estimated from subscapular and triceps skinfolds, and the age-specific relationships between percent fat and chronic disease risk factors (e.g., blood pressure, lipids and lipoprotein levels, glucose, insulin, and circulating C-reactive protein levels) were described in boys and girls, aged 6-18 years.

RESULTS

Percent fat was significantly related to risk factor levels. At higher levels of percent fat, the prevalence of adverse cardiovascular disease risk factors was higher, particularly above 20% fat in boys and above 30% fat in girls. In boys and girls, the interaction term age by percent fat was a significant predictor of risk factors, whereas the percent fat by race interaction term was nonsignificant.

CONCLUSIONS

The results demonstrate a strong relationship between chronic disease risk factors and percent fat in children and youth that varies by age in boys and girls.

Association of body fat percentage with lipid concentrations in children and adolescents: United States, 1999-2004

BACKGROUND

BMI is one factor that is used to determine a child's eligibility for lipid screening and treatment. BMI, which is an indirect measure of body fat, may inadequately represent the biological effect of body fat percentage on lipid concentrations.

OBJECTIVE

We examined the relation between directly measured body fat percentage and lipid concentrations in a representative sample of US youths.

DESIGN

Data from 7821 participants aged 8-19 y from the 1999-2004 NHANES were analyzed. Body fat percentage was measured by dual-energy X-ray absorptiometry. Total and HDL-cholesterol concentrations were measured in serum. Serum triglyceride and LDL-cholesterol concentrations were measured in a subsample of 2661 fasting NHANES participants aged 12-19 y. Prevalences of adverse total cholesterol (>200 mg/dL), LDL cholesterol (>130 mg/dL), triglycerides (>150 mg/dL), and HDL cholesterol (<35 mg/dL) were measured.

RESULTS

Approximately 10.0% [±0.7% (SE)] of participants had high total cholesterol, 7.0 ± 0.4% of participants had low HDL cholesterol, 9.7 ± 1.0% of participants had high triglycerides, and 7.6 ± 0.7% of participants had high LDL cholesterol. Prevalence of adverse total cholesterol, HDL cholesterol, triglycerides, and LDL cholesterol in US youths with high adiposity (greater than or equal to the age- and sex-specific 75th percentile of body fat percentage) was significantly greater (P < 0.01) than for participants without high adiposity. In multiple linear regressions adjusted for age, survey period, and race-ethnicity, the variance in lipid concentrations explained by body fat percentage was 2-20% (P < 0.001).

CONCLUSION

Adverse lipid concentrations and high adiposity are significantly associated in youths.

The metabolic syndrome and body composition in childhood cancer survivors

Purpose

Long-term survivors of childhood cancer appear to have an increased risk for the metabolic syndrome, subsequent type 2 diabetes and cardiovascular disease in adulthood compared to healthy children. The purpose of this study was to investigate the frequency of the metabolic syndrome and associated factors in childhood cancer survivors at a single center in Korea.

Methods

We performed a retrospective review of medical records of 98 childhood cancer survivors who were diagnosed and completed anticancer treatment at Samsung Medical Center, Seoul, Korea between Jan. 1996 and Dec. 2007. Parameters of metabolic syndrome were evaluated between Jan. 2008 and Dec. 2009. Clinical and biochemical findings including body fat percentage were analyzed.

Results

A total of 19 (19.4%) patients had the metabolic syndrome. The median body fat percentage was 31.5%. The body mass index and waist circumference were positively correlated with the cranial irradiation dose (r=0.38, P<0.001 and r=0.44, P<0.00, respectively). Sixty-one (62.2%) patients had at least one abnormal lipid value. The triglyceride showed significant positive correlation with the body fat percentage (r=0.26, P=0.03). The high density lipoprotein cholesterol showed significant negative correlation with the percent body fat (r=-0.26, P=0.03).

Conclusion

Childhood cancer survivors should have thorough metabolic evaluation including measurement of body fat percentage even if they are not obese. A better understanding of the determinants of the metabolic syndrome during adolescence might provide preventive interventions for improving health outcomes in adulthood.

Changes in adiposity status from childhood to adolescence: a 6-year longitudinal study in Portuguese boys and girls

BACKGROUND

Cross-sectional data show high prevalence of overweight in Portuguese children, but there are few longitudinal studies describing the patterns of obesity development in the young.

AIM

To examine the trajectories of obesity from late childhood to adolescence.

SUBJECTS AND METHODS

Triceps and subscapular skinfold thickness measurements were carried out in 288 children at age 9 (baseline) and later at age 15 (follow-up). Percentage body fat (%BF) was estimated according to Slaughter equations and the health-related definition of obesity ( ≥ 25%BF in boys and ≥ 30%BF in girls) was used.

RESULTS

In boys, the prevalence of obesity decreased from 21.9% to 14.8% (p < 0.05) while in girls it increased from 14.3% to 19.5%. The incidence of obesity in the 6-year study period was 2.6% and 8.3% for boys and girls, respectively (p < 0.05). In comparison with girls, the percentage of boys that reversed obesity was more than 3-fold higher (3% vs 9.7%, p < 0.05). Obesity tracked moderately in both sexes (Kappa = 0.6, p < 0.001).

CONCLUSION

The results indicate a marked sex difference in the incidence and reversal of obesity from late childhood to adolescence that is unfavourable to girls. Consideration of this difference might be important when designing programmes for the prevention and treatment of obesity focusing on this period.

The identification of children with adverse risk factor levels by body mass index cutoffs from 2 classification systems: the Bogalusa Heart Study

BACKGROUND

The cutoffs from the Centers for Disease Control and Prevention (CDC) growth charts and from the Cooper Institute (FitnessGram) are widely used to identify children who have a high body mass index (BMI).

OBJECTIVE

We compared the abilities of these 2 systems to identify children who have adverse lipid concentrations and blood pressure measurements and the reliability (consistency) of each classification system over time (mean follow-up: 7 y).

DESIGN

A cross-sectional analysis based on data from 22,896 examinations of 5- to 17-y-olds was conducted. Principal components analyses were used to summarize levels of the 5 risk factors, and likelihood ratios and the κ statistic were used to compare the screening abilities of the 2 systems. Of these children, 3972 were included in longitudinal analyses.

RESULTS

There were marked differences in the prevalence of a high FitnessGram BMI by age, with the prevalence among boys increasing from 2.5% to 21% between the ages of 5 and 11 y. The identification of adverse risk factors by the 2 systems was only fair (κ = 0.25), but there was little difference in the abilities of the CDC and FitnessGram cutoffs to identify high-risk children. Longitudinal analyses, however, indicated that the agreement between initial and follow-up FitnessGram classifications was substantially lower than that based on CDC cutoffs (κ = 0.28 compared with 0.49).

CONCLUSIONS

The FitnessGram and CDC cutoffs have similar abilities to identify high-risk children. However, a high FitnessGram BMI is difficult to interpret because the reliability over time is low, and the prevalence increases markedly with age.

Anthropometric screening for silent cardiovascular risk factors in adolescents: The PEP Family Heart Study

BACKGROUND

Central obesity is associated with an increased risk of cardiovascular disease (CVD), but community-wide screening in adolescents is inadequate. Therefore, we examined six simple anthropometric measures for their utility in screening adolescents for seven silent CVD risk factors.

METHODS

A representative community-based sample of 3038 German adolescents (1639 males) aged 12-18 years participated in the study. The association between hypertension, dyslipoproteinemia, fasting hyperglycemia, body mass index, waist circumference (WC), hip circumference, waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), and skinfold thickness was assessed.

RESULTS

The prevalence of central obesity, defined as elevated WC and/or elevated WHtR, was 13.7% and 13.4% in male and female adolescents, respectively. Among these 412 adolescents, risk factor clustering was 3-4 times more frequent than in the 2626 adolescents without central obesity. Central obesity was the only anthropometric variable that significantly predicted increased risk for all seven non-anthropometric CVD risk factors: hypertension (OR 2.5), elevated triglycerides (OR 4.9), LDL-C (OR 2.0), non-HDL-C (OR 2.1), triglyceride/HDL-C ratio > or = 3.5 (OR 7.2), low HDL-C (OR 1.6), fasting glucose (OR 1.3), and risk factor clustering (OR 3.8). General adiposity only detected hyperglycemia (OR 1.8) and hypertension (OR 4.9), whereas skinfold thickness in or above the 90th percentile predicted risk factor clustering (OR 1.9), elevated triglycerides (OR 2.3), and triglyceride/HDL-C (OR 3.9). WHR indicated hypertriglycridemia (OR 2.3).

CONCLUSIONS

Cardiovascular risk factors in adolescents are easily identified by central adiposity.

Metabolic risk varies according to waist circumference measurement site in overweight boys and girls

OBJECTIVES

To compare waist circumference (WC) values measured at 4 commonly recommended sites and examine the relationships between WC sites and markers of metabolic risk in a sample of overweight boys and girls referred for weight management.

STUDY DESIGN

Overweight (mean body mass index percentile, 98.7; SD, 1.0) children and adolescents (n = 73; 41 girls, 32 boys; mean age, 12.5 years; SD, 2.6 years) had WC measured at 4 sites: iliac crest (WC1), narrowest waist (WC2), midpoint between the floating rib and iliac crest (WC3), and umbilicus (WC4). Height, weight, fasting insulin level, glucose level, cholesterol level, and systolic and diastolic blood pressure were also measured.

RESULTS

Overall, WC1 (108.5 cm; SD, 16.3 cm) was greater than WC2 (97.4 cm; SD, 13.6 cm; P < .003), and WC2 was smaller than WC3 (104.3 cm; SD, 15.3 cm; P = .02) and WC4 (108.7 cm; SD, 16.2 cm; P < .0003). With logistic regression, WC2 and WC3 were revealed to be more consistently associated with metabolic syndrome by using 3 different definitions.

CONCLUSION

In our sample, we observed differences in 4 commonly recommended WC measurement sites and found that all sites were not equivalently associated with metabolic risk. Our findings provide preliminary support suggesting that WC measured at the narrowest waist and midpoint between the floating rib and iliac crest may represent the measurement sites most closely associated with metabolic risk in overweight boys and girls.

Body Fat Percentages by Dual-energy X-ray Absorptiometry Corresponding to Body Mass Index Cutoffs for Overweight and Obesity in Indian Children

BACKGROUND

Indians are suspected to have higher body fat percent at a given body mass index (BMI) than their western counterparts.

OBJECTIVE

To estimate percent body fat in apparently healthy Indian children and adolescents by dual-energy X-ray absorptiometry (DXA) and explore linkages of BMI with body fat percent for better health risk assessment.

METHODS

Age, weight, height of 316 boys and 250 girls (6-17 years) were recorded. Body composition was measured by dual-energy X-ray absorptiometry (DXA). High adiposity was defined as body fat percent (BF%) > McCarthy's 85th percentile of body fat reference data. Receiver operating characteristic analysis (ROC) was carried out for CDC BMI Z score for it's ability to judge excess fatness.

RESULTS

High BF% was seen in 38.5% boys and 54.0% girls (p < 0.05). Percentage of obese children as defined by the BMI cutoffs of International Obesity Task Force (IOTF) (2.1% for boys and 6.9% for girls) was lower than that using Indian (13.7% for boys and 20.9% for girls) and CDC (14.1% for boys and 20.9% for girls) cutoffs. The point closest to one on the ROC curves of CDC BMI Z-scores indicated high adiposity at BMI cutoff of 22 at the age of 17 yr in both the genders.

CONCLUSIONS

Higher body fat percentage is associated with lower BMI values in Indian children.

The validity of BMI as an indicator of body fatness and risk among children

PURPOSE OF REVIEW

Although the prevalence of childhood obesity, as assessed by BMI (kg/m(2)), has tripled over the last 3 decades, this index is a measure of excess weight rather than excess body fatness. In this review we focus on the relation of BMI to body fatness and health risks, particularly on the ability of BMI for age >or=95th Centers for Disease Control and Prevention [CDC] percentile to identify children who have excess body fatness. We also examine whether these associations differ according to race/ethnicity and whether skinfold and circumference measurements provide additional information on body fatness or health risks.

RESULTS

The accuracy of BMI varies according to the degree of body fatness. Among relatively fat children, BMI is a good indicator of excess adiposity, but differences in the BMIs of relatively thin children can be largely due to fat-free mass. Although the accuracy of BMI in identifying children with excess body fatness depends on the chosen cut points, we have found that a high BMI-for-age has a moderately high (70%-80%) sensitivity and positive predictive value, along with a high specificity (95%). Children with a high BMI are much more likely to have adverse risk factor levels and to become obese adults than are thinner children. Skinfold thicknesses and the waist circumference may be useful in identifying children with moderately elevated levels of BMI (85th to 94 th percentiles) who truly have excess body fatness or adverse risk factor levels.

CONCLUSION

A BMI for age at >or=95th percentile of the CDC reference population is a moderately sensitive and a specific indicator of excess adiposity among children.

Classification of body fatness by body mass index-for-age categories among children

OBJECTIVE

To examine the ability of various body mass index (BMI)-for-age categories, including the Centers for Disease Control and Prevention's 85th to 94th percentiles, to correctly classify the body fatness of children and adolescents.

DESIGN

Cross-sectional.

SETTING

The New York Obesity Research Center at St Luke's-Roosevelt Hospital from 1995 to 2000.

PARTICIPANTS

Healthy 5- to 18-year-old children and adolescents (N = 1196) were recruited in the New York City area through newspaper notices, announcements at schools and activity centers, and word of mouth.

MAIN OUTCOME MEASURES

Percent body fat as determined by dual-energy x-ray absorptiometry. Body fatness cutoffs were chosen so that the number of children in each category (normal, moderate, and elevated fatness) would equal the number of children in the corresponding BMI-for-age category (<85th percentile, 85th-94th percentile, and > or =95th percentile, respectively).

RESULTS

About 77% of the children who had a BMI for age at or above the 95th percentile had an elevated body fatness, but levels of body fatness among children who had a BMI for age between the 85th and 94th percentiles (n = 200) were more variable; about one-half of these children had a moderate level of body fatness, but 30% had a normal body fatness and 20% had an elevated body fatness. The prevalence of normal levels of body fatness among these 200 children was highest among black children (50%) and among those within the 85th to 89th percentiles of BMI for age (40%).

CONCLUSION

Body mass index is an appropriate screening test to identify children who should have further evaluation and follow-up, but it is not diagnostic of level of adiposity.

Relation of body mass index and skinfold thicknesses to cardiovascular disease risk factors in children: the Bogalusa Heart Study

BACKGROUND

Adverse levels of cardiovascular disease (CVD) risk factors are related to skinfold thicknesses and body mass index (BMI) among children, but the relative strengths of these associations are unknown.

OBJECTIVE

The objective was to determine whether the sum of the triceps and subscapular skinfold thicknesses (SF sum) is more strongly related to levels of 6 risk factors (triglycerides, LDL and HDL cholesterol, insulin, and systolic and diastolic blood pressure) than is BMI.

DESIGN

Cross-sectional analyses of schoolchildren examined in the Bogalusa Heart Study from 1981 to 1994 (n = 6866) were conducted. A risk factor summary index was derived by using principal components analysis.

RESULTS

After race, sex, study period, and age were controlled for, almost all comparisons indicated that BMI was more strongly related to risk factor levels than was the SF sum. Although the differences were generally small, many were statistically significant. Associations with the risk factor summary, for example, were r = 0.50 for BMI and r = 0.47 for SF sum (P < 0.001 for difference). Furthermore, an adverse risk factor summary was observed among 62% of the children with the highest (upper 5%) BMI levels but among only 54% of children with the highest SF sum levels.

CONCLUSIONS

BMI is at least as accurate as SF sum in identifying children and adolescents who are at metabolic risk. Because of the training and errors associated with skinfold-thickness measurements, the advantages of BMI should be considered in the design and interpretation of clinical and epidemiologic studies.

Obesity and metabolic changes are common in young childhood brain tumor survivors

BACKGROUND

A population based cross-sectional study was used to examine the prevalence of metabolic syndrome and its components in childhood brain tumor survivors.

PROCEDURE

Fifty-two survivors were examined at a mean age of 14.4 years (range 3.8-28.7). Lipid and glucose metabolism, thyroid function, and plasma uric acid were evaluated. Fat mass and fat percentage were assessed by dual-energy X-ray absorptiometry (DXA). Metabolic syndrome was defined on International Diabetes Federation criteria.

RESULTS

Ten (19%) patients were overweight and four (8%) were obese. According to DXA, 16/46 (35%) patients were obese. Central obesity was found in 11 (21%) patients. Cranial irradiation, hypothalamic/hypophyseal damage, growth hormone (GH) deficiency and impaired mobility were associated with overweight/obesity and central obesity. Thirteen (25%) subjects had hypercholesterolemia, 14 (27%) had raised low-density lipoprotein cholesterol (LDL-C), 12 (23%) had raised blood pressure, four (8%) had metabolic syndrome, two (4%) had hyperinsulinemia and five (10%) had hyperuricemia. Cranial irradiation was associated with hypercholesterolemia (P = 0.019), raised LDL-C (P = 0.028), raised blood pressure (P = 0.040), and metabolic syndrome (P = 0.018). Impaired mobility was associated with hypercholesterolemia (P = 0.034). Hypothalamic/hypophyseal damage was associated with metabolic syndrome (P = 0.003) and hyperuricemia (P = 0.011) as was GH deficiency (P = 0.034 and P = 0.008). GH supplementation alleviated adverse metabolic outcomes among brain tumor survivors with GH deficiency.

CONCLUSIONS

Obesity/overweight, dyslipidemia, hypertension, metabolic syndrome, and hyperuricemia were common in young childhood brain tumor survivors. Cranial irradiation, hypothalamic/hypophyseal damage, growth hormone deficiency, and/or impaired mobility were associated with higher risk for obesity and metabolic changes among these patients.

Obesity attenuates the contribution of African admixture to the insulin secretory profile in peripubertal children: a longitudinal analysis

The pubertal transition has been identified as a time of risk for development of type 2 diabetes, particularly among vulnerable groups, such as African Americans (AAs). Documented ethnic differences in insulin secretory dynamics may predispose overweight AA adolescents to risk for type 2 diabetes. The objectives of this longitudinal study were to quantify insulin secretion and clearance in a cohort of 90 AA and European American (EA) children over the pubertal transition and to explore the association of genetic factors and adiposity with repeated measures of insulin secretion and clearance during this critical period. Insulin sensitivity was determined by intravenous glucose tolerance test (IVGTT) and minimal modeling; insulin secretion and clearance by C-peptide modeling; genetic ancestry by admixture analysis. Mixed-model longitudinal analysis indicated that African genetic admixture (AfADM) was independently and positively associated with first-phase insulin secretion within the entire group (P < 0.001), and among lean children (P < 0.01). When examined within pubertal stage, this relationship became significant at Tanner stage 3. Total body fat was a significant determinant of first-phase insulin secretion overall and among obese children (P < 0.001). Total body fat, but not AfADM, was associated with insulin clearance (P < 0.001). In conclusion, genetic factors, as reflected in AfADM, may explain greater first-phase insulin secretion among peripubertal AA vs. EA; however, the influence of genetic factors is superseded by adiposity. The pubertal transition may affect the development of the beta-cell response to glucose in a manner that differs with ethnic/genetic background.

Adiposity measures as indicators of metabolic risk factors in adolescents

AIM

To examine the relation between adiposity assessment methods (percentage body fat (%BF), BMI, and waist circumference (WC)) and individual metabolic risk factors (f-insulin, HDL cholesterol, triglycerides) and a combined measure of metabolic risk.

METHODS

Crosssectional study of 300 males (BMI 20.8 +/- 3.0 kg/m(2)) and females (BMI 21.3 +/- 2.9 kg/m(2)) 17 years of age. F-insulin and components of the metabolic syndrome defined by the International Diabetes Federation (IDF) were used as metabolic risk indicators, with samples stratified into BMI, %BF, and WC groups, respectively. Diagnostic accuracy was expressed as the area under the ROC curve (AUC).

RESULTS

In males, diagnostic accuracy for HDL and f-insulin was poor to fair for BMI (AUC 0.70, p = 0.001; 0.60, p = 0.22), WC (0.68, p = 0.003; 0.63, p = 0.11), and %BF (0.65, p = 0.009; 0.66, p = 0.04). The diagnostic accuracy for triglycerides was greater for all three measures (BMI 0.92, WC 0.95, %BF 0.87; all p < 0.001). For females, neither test performed better than chance for f-insulin and HDL, and only %BF performed better than chance for triglycerides (0.65, p = 0.08). All three measures exhibited higher accuracy for presence of > or =2 metabolic risk factors (AUCs 0.76-0.91, p < 0.001) in both sexes.

CONCLUSION

%BF was not superior to BMI and WC for detecting metabolic risk in the general adolescent population.

Family-centered collaborative negotiation: a model for facilitating behavior change in primary care

PURPOSE

To describe a parent-child-based model that melds a family-centered interaction approach, Touchpoints, with brief negotiation strategies (an adaptation of motivational interviewing) to address health risks in children. An application of the model for addressing childhood overweight in the primary care setting is presented.

DATA SOURCES

Selected research, theoretical, and clinical articles; national recommendations and guidelines; and a clinical case.

CONCLUSIONS

Lifestyle health behaviors are learned and reinforced within the family; thus, changes to promote child health require family involvement. Interventions that engage parents and support parent-child relationships, while enhancing motivation and the abilities to change behavior, are recommended.

IMPLICATIONS FOR PRACTICE

Primary care is an appropriate setting for addressing lifestyle health behaviors. A collaborative partnership, rather than a prescriptive manner, is advocated for primary care providers when working to facilitate health-promoting behavior.

DXA: can it be used as a criterion reference for body fat measurements in children?

OBJECTIVE

Dual-energy X-ray absorptiometry (DXA) is often cited as a criterion method for body composition measurements. We have previously shown that a new DXA software version (Hologic Discovery V12.1) will affect whole-body bone mineral results for subjects weighing <40 kg. We wished to reanalyze pediatric whole-body scans in order to assess the impact of the new software on pediatric soft-tissue body composition estimates.

METHODS AND PROCEDURES

We reanalyzed 1,384 pediatric scans (for ages 1.7-17.2 years) using Hologic software V12.1, previously analyzed using V11.2. Regression analysis and ANCOVA were used to compare body fat (total body fat (TBF), percentage fat (%BF)), and non-bone lean body mass (LBM) for the two versions, adjusting for gender, age and weight.

RESULTS

Software V12.1 yielded values that were higher for TBF, lower for LBM, and unchanged for DXA-derived weight in subjects weighing <40 kg. Body composition values for younger, smaller subjects were most affected, and girls were more affected than boys. Using the new software, 14% of the girls and 10% of the boys were reclassified from the "normal" %BF range to "at risk of obesity," while 7 and 5%, respectively, were reclassified as obese.

DISCUSSION

Hologic's newest DXA software has a significant effect on soft-tissue results for children weighing <40 kg. The effect is greater for girls than boys. Comparison of TBF estimates with previous studies that use older DXA instruments and software should be done with caution. DXA has not yet achieved sufficient reliability to be considered a "gold standard" for body composition assessment in pediatric studies.