Home-based exergaming among children with overweight and obesity: a randomized clinical trial.

BACKGROUND: Given children's low levels of physical activity and high prevalence of obesity, there is an urgent need to identify innovative physical activity options. OBJECTIVE: This study aims to test the effectiveness of exergaming (video gaming that involves physical activity) to reduce children's adiposity and improve cardiometabolic health. METHODS: This randomized controlled trial assigned 46 children with overweight/obesity to a 24-week exergaming or control condition. Intervention participants were provided a gaming console with exergames, a gameplay curriculum (1 h per session, three times a week) and video chat sessions with a fitness coach (telehealth coaching). Control participants were provided the exergames following final clinic visit. The primary outcome was body mass index (BMI) z-score. Secondary outcomes were fat mass by dual energy X-ray absorptiometry and cardiometabolic health metrics. RESULTS: Half of the participants were girls, and 57% were African-American. Intervention adherence was 94.4%, and children's ratings of acceptability and enjoyment were high. The intervention group significantly reduced BMI z-score excluding one control outlier (intervention [standard error] vs. control [standard error]: -0.06 [0.03] vs. 0.03 [0.03], p = 0.016) with a marginal difference in intent-to-treat analysis (-0.06 [0.03] vs. 0.02 [0.03], p = 0.065). Compared with control, the intervention group improved systolic blood pressure, diastolic blood pressure, total cholesterol, low-density lipoprotein-cholesterol and moderate-to-vigorous physical activity (all p values <0.05). CONCLUSIONS: Exergaming at home elicited high adherence and improved children's BMI z-score, cardiometabolic health and physical activity levels. Exergaming with social support may be promoted as an exercise option for children.

A randomized controlled trial of dance exergaming for exercise training in overweight and obese adolescent girls.

BACKGROUND: Structured exergaming with prescribed moderate intensity physical activity has reduced adiposity among adolescents. The extent to which adolescents reduce adiposity when allowed to self-select intensity level is not known. OBJECTIVE: The objective of the study was to examine the influence of exergaming on adolescent girls' body composition and cardiovascular risk factors. METHODS: This randomized controlled trial assigned 41 overweight and obese girls aged 14 to 18 years to group-based dance exergaming (36 h over 3 months) or to a self-directed care control condition. Body size and composition were measured by anthropometry, dual-energy X-ray absorptiometry [%fat and bone mineral density {BMD}] and magnetic resonance imaging. Cardiovascular risk factors included blood pressure, cholesterol, triglycerides, glucose and insulin. RESULTS: Attrition was 5%. Using analysis of covariance controlling for baseline value, age and race, there were no significant condition differences. Per protocol (attended >75%), the intervention group significantly decreased abdominal subcutaneous adiposity and increased trunk and spine BMD (ps < 0.05). Per protocol (>2600 steps/session), the intervention group significantly decreased leg %fat and decreased abdominal subcutaneous and total adiposity (ps < 0.05). CONCLUSION: Exergaming reduced body fat and increased BMD among those adolescent girls who adhered. Further research is required before exergaming is recommended in clinical settings.

An evolving scientific basis for the prevention and treatment of pediatric obesity.

The 2013 Pennington Biomedical Research Center's Scientific Symposium focused on the treatment and management of pediatric obesity and was designed to (i) review recent scientific advances in the prevention, clinical treatment and management of pediatric obesity, (ii) integrate the latest published and unpublished findings and (iii) explore how these advances can be integrated into clinical and public health approaches. The symposium provided an overview of important new advances in the field, which led to several recommendations for incorporating the scientific evidence into practice. The science presented covered a range of topics related to pediatric obesity, including the role of genetic differences, epigenetic events influenced by in utero development, pre-pregnancy maternal obesity status, maternal nutrition and maternal weight gain on developmental programming of adiposity in offspring. Finally, the relative merits of a range of various behavioral approaches targeted at pediatric obesity were covered, together with the specific roles of pharmacotherapy and bariatric surgery in pediatric populations. In summary, pediatric obesity is a very challenging problem that is unprecedented in evolutionary terms; one which has the capacity to negate many of the health benefits that have contributed to the increased longevity observed in the developed world.

Sitting time and cardiometabolic risk in US adults: associations by sex, race, socioeconomic status and activity level.

BACKGROUND: Sitting time is associated with adverse health outcomes including chronic disease and premature mortality. However, it is not known if the association of sitting time with cardiometabolic risk factors varies across sociodemographic or health factors. METHODS: The sample included 4560 adults (≥20 years) who participated in the cross-sectional 2007-2010 US National Health and Nutrition Examination Survey. Participants self-reported typical daily sitting time. Weight, height, blood pressure, and fasting triglycerides, high-density lipoprotein-cholesterol (HDL-C), glucose and insulin were measured. Homeostatic model assessment-insulin resistance (HOMA-IR) and ß cell function (HOMA-%B) were calculated. A subsample of 3727 participants underwent an oral glucose tolerance test to obtain 2 h postload glucose levels. Population-weighted linear regression analysis was used to examine the association between sitting time and each cardiometabolic risk factor, stratified by sex, race, socioeconomic status and activity level. Analyses were controlled for demographics, socioeconomic status, survey cycle, personal and family medical history, diet and physical activity. RESULTS: Sitting time was significantly associated with adverse levels of waist circumference, body mass index, triglycerides, HDL-C, insulin, HOMA-IR, HOMA-%B and 2 h postload glucose, but not with blood pressure or glucose level. In stratified analyses, sitting time was most consistently related to cardiometabolic risk factors among low and middle socioeconomic groups and for those who reported no weekly physical activity, but there were few differences between sex or race groups. CONCLUSIONS: Self-reported sitting time was associated with adverse cardiometabolic risk factors consistently across sex and race groups in a representative US sample, independent of other risk factors. Excessive sitting warrants a public health concern.

Ethnic and sex differences in visceral, subcutaneous, and total body fat in children and adolescents.

OBJECTIVE: This study investigated ethnic and sex differences in the distribution of fat during childhood and adolescence. DESIGN AND METHODS: A cross-sectional sample (n = 382), aged 5-18 years, included African American males (n = 84), White males (n = 96), African American females (n = 118), and White females (n = 84). Measures for total body fat (TBF) mass and abdominal adipose tissue (total volume and L4-L5 cross-sectional area) for both subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) depots were assessed by dual-energy X-ray absorptiometry and magnetic resonance image, respectively. Analyses of covariance (ANCOVAs) were used to determine ethnic and sex differences in TBF (adjusted for age) and ethnic and sex differences in SAT and VAT (adjusted for both age and TBF). RESULTS: Age-adjusted TBF was greater in African Americans (P = 0.017) and females (P < 0.0001) compared with Whites and males, respectively. In age- and TBF-adjusted ANCOVAs, no differences were found in the SAT. The VAT volume was, however, greater in Whites (P < 0.0001) and males (P < 0.0001) compared with African Americans and females, respectively. Similar patterns were observed in SAT and VAT area at L4-L5. CONCLUSIONS: The demonstrated ethnic and sex differences are important confounders in the prevalence of obesity and in the assignment of disease risk in children and adolescents.

Waist circumference measurement site does not affect relationships with visceral adiposity and cardiometabolic risk factors in children.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: A number of anatomic sites are used for the measurement of waist circumference. A number of studies have documented differences in the absolute values of waist circumference measurements across these common sites in adults. It is unclear whether waist circumference measurement site alters the relationship with abdominal adiposity and cardiometabolic risk factors in children. WHAT THIS STUDY ADDS: The absolute values of waist circumference at four anatomic locations (minimal, midway, iliac, umbilicus) differed and this affected prevalence of high (≥90th percentile) waist circumference. The relationships between waist circumference values at four anatomic locations and both depot-specific adiposity and cardiometabolic risk factors were similar across race and sex groups. BACKGROUND: Different waist circumference (WC) measurement sites are used in clinical and epidemiological settings. OBJECTIVES: To examine differences in WC measurement at four anatomic sites and how each WC measurement relates to visceral adipose tissue (VAT) and cardiometabolic risk factors in children. METHODS: A total of 371 white and African-American children aged 5 to 18 years had WC measured at four sites: minimal waist, midpoint between the iliac crest and the lowest rib, superior border of the iliac crest and the umbilicus. Abdominal VAT was measured using magnetic resonance imaging and cardiometabolic risk factors were defined using National Heart, Lung and Blood Institute guidelines. Relationships between WC sites and VAT and risk factors were explored in each race-by-sex group. RESULTS: All WC sites were highly correlated (r = 0.97 to 0.99). Differences in absolute mean WC values existed in all race-by-sex groups, and this affected the prevalence of high WC (≥90th percentile). Values were lowest for minimal waist and highest for umbilicus. Age-controlled partial correlations between WC and logVAT VAT were 0.81-0.89 (all P < 0.001) and between WC and cardiometabolic risk factors were -0.24 to -0.41 and 0.19 to 0.52 (all P < 0.05). CONCLUSIONS: While the absolute values of WC at four anatomic locations differed, the relationships between WC values and both VAT and cardiometabolic risk factors were similar within all race-by-sex groups.

BMI percentiles for the identification of abdominal obesity and metabolic risk in children and adolescents: evidence in support of the CDC 95th percentile.

OBJECTIVES: Body mass index (BMI) percentiles have been routinely and historically used to identify elevated adiposity. The aim of this study was to investigate the optimal Centers for Disease Control and Prevention (CDC) BMI percentile that predicts elevated visceral adipose tissue (VAT), fat mass and cardiometabolic risk in a biracial sample of children and adolescents. PARTICIPANTS AND METHODS: This cross-sectional analysis included 369 white and African-American children (5-18 years). BMI was calculated using height and weight and converted to BMI percentiles based on CDC growth charts. Receiver operating characteristic curve analysis identified the optimal (balance of sensitivity and specificity) BMI percentile to predict the upper quartile of age-adjusted VAT (measured by magnetic resonance imaging), age-adjusted fat mass (measured by dual-energy X-ray absorptiometry) and elevated cardiometabolic risk (≥ 2 of high glucose, triglycerides and blood pressure, and low high-density lipoprotein cholesterol) for each race-by-sex group. RESULTS: The optimal CDC BMI percentile to predict those in the top quartile of age-adjusted VAT, age-adjusted fat mass and elevated cardiometabolic risk were the 96th, the 96th and the 94th percentiles, respectively, for the sample as a whole. Sensitivity and specificity was satisfactory (>0.70) for VAT and fat mass. Compared to VAT and fat mass, there was a lower overall accuracy of the optimal percentile in identifying those with elevated cardiometabolic risk. CONCLUSIONS: The present findings support the utility of the 95th CDC BMI percentile as a useful threshold for the prediction of elevated levels of VAT, fat mass and cardiometabolic risk in children and adolescents.

Validity assessment of a portable bioimpedance scale to estimate body fat percentage in white and African-American children and adolescents.

OBJECTIVE: The objective of the study was to determine accuracy of the Tanita SC-240 body composition analyser to measure paediatric percent body fat (%BF). METHODS: Eighty-nine African-American and white 5-18-year-olds participated in this study. %BF was estimated by dual-energy X-ray absorptiometry (DXA) and by the Tanita SC-240. RESULTS: Overall %BF was 33.5 ± 10.5% (Tanita SC-240) vs. 34.5 ± 8.7% (DXA). There was no significant difference between the two measures (P = 0.52, average error = -1.0%, average absolute error = 3.9%). The Tanita mean %BF estimates significantly differed from the DXA mean %BF in white boys (P = 0.001, Cohen's d = 0.40) and white girls (P = 0.006, Cohen's d = 0.48), but differences were of small effect. No differences in %BF estimates were found for African-American boys or girls. CONCLUSIONS: In this sample, the Tanita SC-240 demonstrated acceptable accuracy for estimating %BF when compared with DXA, supporting its use in field studies.

Ethnic and sex differences in body fat and visceral and subcutaneous adiposity in children and adolescents.

Body fat and the specific depot where adipose tissue (AT) is stored can contribute to cardiometabolic health risks in children and adolescents. Imaging procedures including magnetic resonance imaging and computed tomography allow for the exploration of individual and group differences in pediatric adiposity. This review examines the variation in pediatric total body fat (TBF), visceral AT (VAT) and subcutaneous AT (SAT) due to age, sex, maturational status and ethnicity. TBF, VAT and SAT typically increase as a child ages, though different trends emerge. Girls tend to accumulate more TBF and SAT during and after puberty, depositing fat preferentially in the gynoid and extremity regions. In contrast, pubertal and postpubertal boys tend to deposit more fat in the abdominal region, particularly in the VAT depot. Sexual maturation significantly influences TBF, VAT and SAT. Ethnic differences in TBF are mixed. VAT tends to be higher in white and Hispanic youth, whereas SAT is typically higher in African American youth. Asian youth typically have less gynoid fat but more VAT than whites. Obesity per se may attenuate sex and ethnic differences. Particular health risks are associated with high amounts of TBF, VAT and SAT, including insulin resistance, hepatic steatosis, metabolic syndrome and hypertension. These risks are affected by genetic, biological and lifestyle factors including physical activity, nutrition and stress. Synthesizing evidence is difficult as there is no consistent methodology or definition to estimate and define depot-specific adiposity, and many analyses compare SAT and VAT without controlling for TBF. Future research should include longitudinal examinations of adiposity changes over time in representative samples of youth to make generalizations to the entire pediatric population and examine variation in organ-specific body fat.

Body mass index versus waist circumference as predictors of mortality in Canadian adults.

BACKGROUND: Elevated body mass index (BMI) and waist circumference (WC) are associated with increased mortality risk, but it is unclear which anthropometric measurement most highly relates to mortality. We examined single and combined associations between BMI, WC, waist-hip ratio (WHR) and all-cause, cardiovascular disease (CVD) and cancer mortality. METHODS: We used Cox proportional hazard regression models to estimate relative risks of all-cause, CVD and cancer mortality in 8061 adults (aged 18-74 years) in the Canadian Heart Health Follow-Up Study (1986-2004). Models controlled for age, sex, exam year, smoking, alcohol use and education. RESULTS: There were 887 deaths over a mean 13 (SD 3.1) years follow-up. Increased risk of death from all-causes, CVD and cancer were associated with elevated BMI, WC and WHR (P<0.05). Risk of death was consistently higher from elevated WC versus BMI or WHR. Ascending tertiles of each anthropometric measure predicted increased CVD mortality risk. In contrast, all-cause mortality risk was only predicted by ascending WC and WHR tertiles and cancer mortality risk by ascending WC tertiles. Higher risk of all-cause death was associated with WC in overweight and obese adults and with WHR in obese adults. Compared with non-obese adults with a low WC, adults with high WC had higher all-cause mortality risk regardless of BMI status. CONCLUSION: [corrected] BMI and WC predicted higher all-cause and cause-specific mortality, and WC predicted the highest risk for death overall and among overweight and obese adults. Elevated WC has clinical significance in predicting mortality risk beyond BMI.