COVID-19: quarantine, isolation, and lifestyle diseases

Within just a month of the first case of idiopathic pneumonia, on 30 January 2020, WHO declared the outbreak, a Public Health Emergency of International Concern. On 11 February 2019, the Internal Committee on Taxonomy of Virus (ICTV) announced the name of the novel virus as "severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)" and on 11 March 2020, WHO declared it a global pandemic. As a preventive measure, the government of several countries has imposed quarantine and isolation for preventing the further spread of disease. Both of these restrict outdoor activities, which can directly affect the lifestyle of citizens. Quarantine for the long term can result in increased lifestyle disease, mainly cardiovascular diseases, and obesity.

Physiological Changes and Pathological Pain Associated with Sedentary Lifestyle-Induced Body Systems Fat Accumulation and Their Modulation by Physical Exercise

A sedentary lifestyle is associated with overweight/obesity, which involves excessive fat body accumulation, triggering structural and functional changes in tissues, organs, and body systems. Research shows that this fat accumulation is responsible for several comorbidities, including cardiovascular, gastrointestinal, and metabolic dysfunctions, as well as pathological pain behaviors. These health concerns are related to the crosstalk between adipose tissue and body systems, leading to pathophysiological changes to the latter. To deal with these health issues, it has been suggested that physical exercise may reverse part of these obesity-related pathologies by modulating the cross talk between the adipose tissue and body systems. In this context, this review was carried out to provide knowledge about (i) the structural and functional changes in tissues, organs, and body systems from accumulation of fat in obesity, emphasizing the crosstalk between fat and body tissues; (ii) the crosstalk between fat and body tissues triggering pain; and (iii) the effects of physical exercise on body tissues and organs in obese and non-obese subjects, and their impact on pathological pain. This information may help one to better understand this crosstalk and the factors involved, and it could be useful in designing more specific training interventions (according to the nature of the comorbidity).

Sex-specific differences in somatic investment and strategies of physical activity among Portuguese schoolchildren

OBJECTIVES

Physical activity (PA) is required for healthy growth, development, and maturation and plays an important role in the prevention of overweight and obesity in childhood and adolescence. Sex-differences in PA levels are well documented, with boys spending more time in PA, especially in moderate-to-vigorous activities. Following the Life History Theory, our aim is to study if PA affects the fat tissues increases during childhood and juvenile phases in both sexes.

METHODS

Time spent in sedentary, light, and moderate-to-vigorous PA levels were measured in a sample of 415 Portuguese children and juveniles (207 females/208 males; aged 6-11 years), using an accelerometer for 7 days. Skinfolds related with body fat were objectively collected and socioeconomic status factors were reported using a parental questionnaire.

RESULTS

The outcomes show that girls' and boys' fat variables increased during the end of the childhood and the juvenile phase. However, these variables were differently affected by PA. Girls increased fat variables with the sedentary activity while boys decreased fat variables with moderate-to-vigorous PA. Alike, active boys but not girls reduced the fat increase tendency with age.

CONCLUSIONS

Although both sexes displayed a general fat increment with age, moderate-to-vigorous PA dampens the increase only in boys. In fact, active girls increased body fat in the same manner as non-active girls. From an evolutionary perspective, it could explain sex-specific somatic strategies related to future reproduction or, with future mating and intrasexual competition.

Reductions in Cardiopulmonary Disease Risk Following Calisthenic Concurrent Aerobic and Resistance Training in Young Adults in a Low Resource Setting

Background: Studies have demonstrated that young adults, especially in low- to middle-income countries, are increasingly susceptible to unfavorable alterations in body composition during their transition from adolescence to adulthood. This places young adults at an increased risk for numerous chronic diseases, such as cardiovascular, and/or pulmonary diseases. Objectives: This study aimed to determine if concurrent aerobic and resistance calisthenic training could reduce cardiopulmonary disease risk in young adults in a low resource setting. Methods: Thirty young adult males were randomly assigned to either a six-week non-exercising control group (NON) or concurrent aerobic or resistance training group (CON) that engaged in three, non-consecutive, 60-minute exercise sessions using a combination of 4 - 5 progressive resistance training exercises for two sets of 15 - 20 repetitions and 30 minutes of aerobic exercises at a rating of perceived exertion of 9 - 15. This study assessed anthropometry (body mass, stature, body mass index waist-to-hip ratio, waist-to-stature ratio, sum of skinfolds, percentage body fat, fat mass, fat free mass and conicity index) and lung function (forced vital capacity (FVC), forced expired volume in one second (FEV1), forced expiratory volume in one second/forced vital capacity ratio (FEV1/FVC), peak expiratory flow (PEF), maximal expiratory flow at 75% (MEF75%), maximal expiratory flow at 50% (MEF50%) and maximal expiratory flow at 25 (MEF25%). Results: Concurrent training resulted in significant (P ≤ 0.05) improvements in waist-to-hip ratio (0.94 ± 0.04 to 0.92 ± 0.05; P = 0.042), fat free mass (57.46 ± 9.16 to 58.21 ± 8.65 kg; P = 0.018), percentage body fat (14.56 ± 5.96 to 13.24 ± 5.77%, P = 0.006), fat mass (10.22 ± 5.31 to 9.29 ± 5.17 kg; P = 0.008), sum of skinfolds (96.22 ± 35.64 to 87.67 ± 32.15 mm; P = 0.004), PEF (5.06 ± 2.04 to 6.57 ± 2.51 L; P = 0.018), MEF75% (4.78 ± 2.01 to 6.24 ± 1.99 L.sec-1; P = 0.026), MEF50% (4.08 ± 1.20 to 5.24 ± 1.44 L.sec-1; P = 0.043) and MEF25% (2.66 ± 0.63 to 3.31 ± 1.87 L.sec-1; P = 0.038). Conclusions: The findings support the feasibility and efficacy of a simple and inexpensive concurrent aerobic and resistance training program to simultaneously improve body composition and lung function in an attempt to curb the increasing incidence of overweight/obesity and associated lung dysfunction in young adults in a low resource setting.

The Association between Physical Fitness Performance and Abdominal Obesity Risk among Taiwanese Adults: A Cross-Sectional Study

The present study aims to investigate the associations between physical fitness performance and abdominal obesity risk among Taiwanese adults. We conducted a cross-sectional study and reviewed the data derived from the National Physical Fitness Survey in Taiwan (HPFSIT). Data from a total of 62,486 respondents aged 23–64 years were collected in this study. The participants completed a standardized structural questionnaire and a series of anthropometric characteristics (body mass index and waist-to-hip ratio) and physical fitness (3-min step tests, 1-min sit-up tests, and sit-and-reach tests) assessments. Waist circumference was used to define abdominal obesity status. A multiple logistic regression analysis was conducted. Our results presented almost entirely significant associations (except for women) on the 3-min step test. Moreover, the results suggest that muscular strength, endurance, and flexibility may be effective predictors of abdominal obesity among men and women, whereas cardiorespiratory fitness predicted abdominal obesity only in men. According to the results of this study, the fitness–abdominal obesity associations are minor based on a mixed population analysis. However, dose–response relationships have been observed. The present study provides a new perspective by using different types of fitness performance to predict abdominal obesity.

Effects of exercise intervention on visceral fat in obese children and adolescents

INTRODUCTION

This meta-analysis study was aimed to assess the effects of exercise intervention on visceral fat in obese children and adolescents.

EVIDENCE ACQUISITION

Electronic database searches were performed in Academic Search Complete, CINAHL, Healthsource, MEDLINE, and SportDiscus, and from the earliest record to November 2017. Keywords included "exercise or training," "visceral fat," and "child or adolescent or youth." The inclusion criteria for eligible studies were as follows: 1) subjects were obese at baseline; 2) aged 6-19 years; 3) visceral fat was reported at baseline and after an intervention; and 4) studies were published in peer-reviewed journals written in English.

EVIDENCE SYNTHESIS

A total of 207 studies were observed at the initial search and 73 effect sizes (ESs) were derived from the 34 selected studies. The overall exercise intervention effect was large (Cohen's d [ES]=-1.003, 95% CI=-1.114, -0.892). Moderator analyses results showed that gender (Qb=8.23, df=2, P=0.016), exercise type (Qb=10.68, df=2, P=0.005), and intervention length (Qb=24.71, df=2, P<0.001) influenced the overall ES.

CONCLUSIONS

The group of both boys and girls (ES=-0.95) who participated combined exercise program (Aerobic + Resistance training; ES=-1.17) for 12 months (ES=-1.24) appeared to be the most effective exercise strategy for reducing visceral fat in obese youth.

Genetic and environmental (physical fitness and sedentary activity) interaction effects on cardiometabolic risk factors in Mexican American children and adolescents

Knowledge on genetic and environmental (G × E) interaction effects on cardiometabolic risk factors (CMRFs) in children is limited.  The purpose of this study was to examine the impact of G × E interaction effects on CMRFs in Mexican American (MA) children (n = 617, ages 6-17 years). The environments examined were sedentary activity (SA), assessed by recalls from "yesterday" (SAy) and "usually" (SAu) and physical fitness (PF) assessed by Harvard PF scores (HPFS). CMRF data included body mass index (BMI), waist circumference (WC), fat mass (FM), fasting insulin (FI), homeostasis model of assessment-insulin resistance (HOMA-IR), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), systolic (SBP) and diastolic (DBP) blood pressure, and number of metabolic syndrome components (MSC). We examined potential G × E interaction in the phenotypic expression of CMRFs using variance component models and likelihood-based statistical inference. Significant G × SA interactions were identified for six CMRFs: BMI, WC, FI, HOMA-IR, MSC, and HDL, and significant G × HPFS interactions were observed for four CMRFs: BMI, WC, FM, and HOMA-IR. However, after correcting for multiple hypothesis testing, only WC × SAy, FM × SAy, and FI × SAu interactions became marginally significant. After correcting for multiple testing, most of CMRFs exhibited significant G × E interactions (Reduced G × E model vs. Constrained model). These findings provide evidence that genetic factors interact with SA and PF to influence variation in CMRFs, and underscore the need for better understanding of these relationships to develop strategies and interventions to effectively reduce or prevent cardiometabolic risk in children.

Associations between body composition, nutrition, and physical activity in young adults

OBJECTIVE

The aim of the present study is to investigate the associations between total energy, macronutrient intakes, and physical activity (PA) and body composition by assessing body fat mass, fat-free mass, and BMI in a population of young adults.

METHODS

The study population consisted of 605 young Spanish adults (median age 20.38 ± 2.67). Body composition, including fat mass and fat-free mass, was calculated with body composition analyzer. Daily energy and macronutrient intakes were measured using a 72-h recall method. The International PA Questionnaire was used to assess PA and sedentary time. Linear regression analyses were performed to test the possible associations between nutrition, PA factors, and body composition.

RESULTS

Linear regression analyses revealed that BMI has a significant positive association with protein intake (P = .004, B = 0.088, 95% CI 0.028-0.149) and an inverse association with carbohydrate intake (P = 0.034, B = -0.027, 95% CI -0.053 - -0.002). Protein intake also demonstrated a significant association with fat-free mass, but the size of the effect was smaller (P = .027, B = 96.965, 95% CI 11.250-182.679). There was evidence of a positive association between total PA and moderate-to-vigorous PA (P < .001, B = 15.630, 95% CI 6.989 -24.270) and fat-free mass (P < .001, B = 20.208, 95% CI 9.694 -30.723). When fat mass was used as the outcome variable, there was no evidence of any association with the PA, total energy, and macronutrient intakes variables analyzed.

CONCLUSIONS

Our findings suggest that PA variables were consistently associated with body composition, specifically fat-free mass. Dietary factors also have influence over body composition; we showed that protein intake is significantly associated with fat-free mass and BMI.

Correlates of longitudinal changes in the waist-to-height ratio of primary school children: Implications for prevention

OBJECTIVE

To investigate correlates of changes in waist-to-height ratio (WHtR) in primary school children in order to identify modifiable factors usable for prevention.

METHODS

Outcome evaluation of a statewide health promotion program in Baden-Württemberg, Germany. Baseline (2010) and follow-up (2011) measurements provided data for the calculation of changes in WHtR. Further information on the health and living conditions of the children were assessed in parental questionnaires. Anthropometric measures were taken in 1733 (50.8% male) first and second grade children (age at baseline 7.1 ± 0.6 years) by staff trained according to ISAK-standards. Stepwise linear regression analysis was applied to identify variables with influence on changes in WHtR.

RESULTS

According to the resulting regression model, changes in WHtR towards an increase were influenced by at least one parent being overweight/obese, at least one parent who smoked, low household income, higher age of the child and the skipping of breakfast. There was no clustering effect in schools observed.

CONCLUSION

A promising target for prevention of gain in WHtR in primary school children is to ensure the regularity of breakfast. Smoking cessation as well as dietary improvements would not only help children's health but also the health of their parents. The socioeconomic influence on the development of an unhealthy weight status has already been acknowledged and should be extensively targeted by all of society and policy makers.

Understanding the Early Signs of Chronic Disease by Investigating the Overlap of Mental Health Needs and Adolescent Obesity

Objective

Childhood obesity has reached epidemic proportions with two to three-fold increases in prevalence in the past three decades. Sedentary lifestyles and nutrition have been linked to these increases though little is known about mental health illnesses in children and teens which may be precursors to negative modifiable health risk factors. The objective of this study was to investigate for a potentially more clinically practical indicator of depression over a multi-item screen in respect to reporting of overweight and obesity in adolescents. This study further investigated modifiers to this association and stability of association.

Method

This cross-sectional study aggregated 2007/2009 California Health Interview Survey data (n = 6,917 adolescents). Univariate analyses of population characteristics and modifiable behaviors with obesity/overweight and depression are presented. Multivariable weighted logistic regression was used to compare the adjusted odds of overweight and obesity for those children with reported depression.

Results

After controlling for gender, race/ethnicity, age, and modifiable behaviors, there was a statistically significant relationship between reported depression and overweight/obesity (OR = 1.24; 95% CI = 1.04, 1.49). This effect size was consistent in hierarchical models overall and stratified by gender.

Conclusions

Overweight and obesity in adolescents should be understood clinically in the context of depression and other mental health illness. This study highlights a routine primary care or parental screening assessment that could indicate tendencies in adolescent boys and girls which may be precursors to overweight or obesity. Further research should be conducted to identify ways for integrating adolescent mental health screens into primary care.

Influence of urban neighbourhood environment on physical activity and obesity-related diseases

OBJECTIVES

The impact of characteristics of neighbourhood environment on physical activity and obesity-related diseases is still the subject of debate. This study aimed to explore the impact of urban neighbourhood environment on physical activity and obesity-related diseases.

STUDY DESIGN

Cross-sectional study.

METHODS

Individuals who participated in the 2009 national health-screening programme, submitted all necessary information, and had lived in Community 1 (Haengdang) or Community 2 (Ilsan) for at least 2 years (n = 16,178) were selected for inclusion in this study. Anthropometric measures were taken and physical activity was assessed using a short questionnaire.

RESULTS

No significant difference in the trigger factors for walking, including the amount of neighbourhood park space, number of shopping malls, and distance between the community and shopping malls, was found between the two communities. However, Community 2 had a better street environment than Community 1. Participants who lived in Community 2 were more physically active [adjusted odds ratio (OR) 1.31, 95% confidence interval (CI) 1.16-1.48] and walked more regularly (adjusted OR 1.09, 95% CI 1.02-1.17) than participants who lived in Community 1, and were less likely to have abdominal obesity (adjusted OR 0.83, 95% CI 0.77-0.91), hypertension (adjusted OR 0.88, 95% CI 0.80-0.97) and diabetes (adjusted OR 0.86, 95% CI 0.75-0.99). However, the risk of dyslipidaemia, especially in terms of low-density lipoprotein cholesterol, was higher in Community 2.

CONCLUSIONS

These results suggest that a walkable environment has a positive influence on hypertension and diabetes, and physical activity is the possible mechanism for this association. A walkable environment may function as an important tool for health promotion in urban areas.

Associations between diet, physical activity and body fat distribution: a cross sectional study in an Indian population

BACKGROUND

Obesity is a growing health problem in India and worldwide, due to changes in lifestyle. This study aimed to explore the independent associations between dietary and physical activity exposure variables and total body fat and distribution in an Indian setting.

METHODS

Individuals who had participated in the Indian Migration Study (IMS) or the Andhra Pradesh Children And Parents' Study (APCAPS), were invited to participate in the Hyderabad DXA Study. Total and abdominal body fat of study participants was measured using DXA scans. Diet and physical activity (PA) levels were measured using questionnaires.

RESULTS

Data on 2208 participants was available for analysis; mean age was 49 yrs in IMS, 21 yrs in APCAPS. Total energy intake was positively associated with total body fat in the APCAPS sample: a 100 kcal higher energy intake was associated with 45 g higher body fat (95% CI 22, 68). In the IMS sample no association was found with total energy intake, but there was a positive association with percent protein intake (1% higher proportion of energy from protein associated with 509 g (95% CI 138,880) higher total body fat). Broadly the same pattern of associations was found with proportion of fat in the abdominal region as the outcome. PA was inversely associated with total body fat in both populations (in APCAPS, one MET-hour higher activity was associated with 46 g (95% CI 12, 81) less body fat; in the IMS it was associated with 145 g less body fat (95% CI 73, 218)). An inverse association was observed between PA and percentage abdominal fat in the IMS but no association was seen in the APCAPS population.

CONCLUSIONS

In this Indian population, there was an inverse association between PA and body fat. Associations between body fat and dietary variables differed between the younger APCAPS population and older IMS population. Further longitudinal research is needed to elucidate causality and directions of these associations across the life course.

Physical activity and cardiovascular risk factors in childhood cancer survivors

BACKGROUND

Childhood cancer survivors (CCS) are at high risk of developing treatment-related late effects, including cardiovascular disease and diabetes. Late effects can be exacerbated by low physical activity (PA) levels. Relationships between PA and cardiovascular risk factors during childhood have not been well described in CCS.

PROCEDURE

PA and cardiovascular risk factors were measured cross-sectionally in 319 CCS and 208 sibling controls aged 9-18 years. Comparisons between CCS and controls and associations of outcomes with PA (dichotomized at 60 min/day or treated as continuous) were performed with linear regression.

RESULTS

Among CCS, the high PA group had lower percent fat mass (24.4% vs. 29.8%, P < 0.0001), abdominal subcutaneous fat (67.9 vs. 97.3 cm³ , P = 0.0004), and abdominal visceral fat (20.0 vs. 24.9 cm³ , P = 0.007) and greater lean body mass (41.3 vs. 39.5 kg, P = 0.009) than the low PA group. Comparing CCS to controls, differences in waist circumference (P_interaction  = 0.04), percent fat mass (P_interaction  = 0.04), and abdominal subcutaneous (P_interaction  = 0.02) and visceral (P_interaction  = 0.004) fat between low and high PA groups were greater in CCS than controls, possibly due to greater overall adiposity in CCS.

CONCLUSIONS

High PA in CCS resulted in an improved cardiovascular profile, consisting primarily of lower fat mass and greater lean mass, similar to that observed in controls. This suggests interventions directed to increase PA in CCS may reduce the risk of future cardiovascular disease. Pediatr Blood Cancer 2015;62:305-310. © 2014 Wiley Periodicals, Inc.

Food consumption, physical activity and socio-economic status related to BMI, waist circumference and waist-to-height ratio in adolescents

OBJECTIVE

To examine the association between obesity and food group intakes, physical activity and socio-economic status in adolescents.

DESIGN

A cross-sectional study was carried out in 2008. Cole's cut-off points were used to categorize BMI. Abdominal obesity was defined by a waist circumference at or above the 90th percentile, as well as a waist-to-height ratio at or above 0·500. Diet was evaluated using an FFQ, and the food group consumption was categorized using sex-specific tertiles of each food group amount. Physical activity was assessed via a self-report questionnaire. Socio-economic status was assessed referring to parental education and employment status. Data were analysed separately for girls and boys and the associations among food consumption, physical activity, socio-economic status and BMI, waist circumference and waist-to-height ratio were evaluated using logistic regression analysis, adjusting the results for potential confounders.

SETTING

Public schools in the Azorean Archipelago, Portugal.

SUBJECTS

Adolescents (n 1209) aged 15-18 years.

RESULTS

After adjustment, in boys, higher intake of ready-to-eat cereals was a negative predictor while vegetables were a positive predictor of overweight/obesity and abdominal obesity. Active boys had lower odds of abdominal obesity compared with inactive boys. Boys whose mother showed a low education level had higher odds of abdominal obesity compared with boys whose mother presented a high education level. Concerning girls, higher intake of sweets and pastries was a negative predictor of overweight/obesity and abdominal obesity. Girls in tertile 2 of milk intake had lower odds of abdominal obesity than those in tertile 1. Girls whose father had no relationship with employment displayed higher odds of abdominal obesity compared with girls whose father had high employment status.

CONCLUSIONS

We have found that different measures of obesity have distinct associations with food group intakes, physical activity and socio-economic status.

The surprising influence of family history to type 2 diabetes on anaerobic performance of young male élite athletes

AIMS/HYPOTHESIS

It is known that family history to type 2 diabetes induces anthropometric changes in various populations. Regular physical activity can induce adaptations in these subjects regularizing body composition and anthropometric parameters. The aim of this study is therefore to understand if family history to type 2 diabetes affects anaerobic performance in young male élite athletes.

METHODS

Forty six young male élite athletes were tested. Thirty three without family history to type 2 diabetes (FH-) and thirteen with family history to type 2 diabetes (FH+). Anthropometric parameters, body composition, physiological parameters and athletic performance were assessed.

RESULTS

Weight (p 0,0050), BMI (p 0,0019), waist circumference (p 0,0090), hips circumference (p 0,0490) and WHR (p 0,0339) were different between the two groups, showing greater values for the FH + subjects. Body composition showed lower FM and higher FFM percentages for the FH + group compared to the FH-. Anaerobic performance tests showed differences between the groups highlighting that the FH + group had higher anaerobic performance values (Wingate test for FH + 512,77 ± 107,93 W vs Wingate test for FH- 447,94 ± 56,95 W).

CONCLUSIONS/INTERPRETATION

The élite athletes with FH + showed better anaerobic performances and a higher body mass. At this stage we cannot generalise, but in a sample of athletes we tested, all who were with FH + showed both interesting and unexpected results; if confirmed, this evidence may represent a remarkable knowledge for fitness coaches and professionals who are daily dealing with track and field athletes and their performances.

Top 10 research questions related to musculoskeletal physical fitness testing in children and adolescents

The purpose of this article is to bring attention to the 10 most pressing questions relevant to musculoskeletal physical fitness testing in children and adolescents. The goal is to stimulate research to answer these questions. The most pressing needs include establishing definitive links between valid, reliable, and feasible field test measures of muscular strength, endurance, power, and flexibility and health risk factors/markers in children and adolescents; determining the effects of exercise training on these relationships; and documenting the tracking of these relationships. The role of flexibility in health-related physical fitness (HRPF) needs to be carefully and specifically examined. Although body weight/composition is a separate component of health-related fitness, it is also a factor that can influence the performance of musculoskeletal test items. The role of body weight, body fat, and central adiposity and the possibility of adjustment of tests results are important research questions. Several questions relate to which field tests are best for use in schools. Finally, actual health-related criterion-referenced cutoff values need to be developed. In conclusion, more quality research is needed to firmly establish the musculoskeletal area for HRPF in youth.

Academic performance in relation to adherence to the Mediterranean diet and energy balance behaviors in Greek primary schoolchildren

OBJECTIVE

To explore possible links between adherence to the Mediterranean Diet (MeD), excess body weight, energy balance behaviors, and academic performance in Greek primary schoolchildren.

DESIGN

Cross-sectional study.

SETTING

Primary schools in Athens, Greece.

PARTICIPANTS

A total of 528 students (256 boys and 272 girls), 10-12 years of age, were recruited from 21 primary schools in the area of Athens, Greece.

MAIN OUTCOME MEASURES

Students completed a specifically designed energy balance behaviors questionnaire together with the KIDMED index, which evaluates the degree of adherence to the MeD. The teacher assessed academic performance through a specifically designed, 5-scale questionnaire. Standard anthropometric measurements were also taken.

ANALYSIS

Block stepwise regression analysis was conducted.

RESULTS

Adherence to the MeD (β = .140; P = .001), obesity (β = -.095; P = .001), physical activity levels (β = .206; P = .001), hours of sleep (β = .100; P = .003), television viewing (β = -.068; P = .05), and global self-esteem levels (β = .122; P = .001) are significant factors in predicting academic performance in primary schoolchildren.

CONCLUSIONS AND IMPLICATIONS

Poor adherence to the MeD, obesity, and low physical activity levels seem to negatively affect academic performance in children. Understanding these interrelationships could facilitate the formation of policies focused on improving children's academic achievement.

Aerobic plus resistance training was more effective in improving the visceral adiposity, metabolic profile and inflammatory markers than aerobic training in obese adolescents

The purpose of this study was to determine whether aerobic plus resistance training (AT + RT) is more effective than aerobic training (AT) at reducing inflammatory markers and cardiovascular risk in obese adolescents. A total of 139 obese adolescents were enrolled, aged 15-19 years, body mass index (BMI) ≥ 95th percentile and participated in 1 year of interdisciplinary intervention. They were randomised into two groups: AT (n = 55), AT + RT (n = 61). Blood samples were collected to analyse glycaemia, insulin, the lipid profile, leptin and adiponectin concentrations. Insulin resistance was measured by homeostasis model assessment of insulin resistance index (HOMA-IR). The AT + RT group showed better results with regard to decreased body fat mass, low-density lipoprotein concentration (LDL-c) levels, subcutaneous and visceral fat and increased body lean mass. Indeed, a reduction of hyperleptinaemia and an increase in adiponectin concentrations, promoting an improvement in the leptin/adiponectin ratio, was observed. Important clinical parameters were improved in both types of exercise; however, AT + RT was more effective in improving the visceral adiposity, metabolic profile and inflammatory markers than AT alone, suggesting clinical applications for the control of intra-abdominal obesity and cardiovascular risk in the paediatric population.

Healthy behaviours and abdominal adiposity in adolescents from southern Italy

OBJECTIVE

The present study aimed to evaluate the prevalence of meeting health recommendations on diet and physical activity (having breakfast, eating fruit and vegetables, consumption of milk/yoghurt, performing moderate-to-vigorous physical activity, limiting television watching) and to assess junk snack food consumption in adolescents from southern Italy. The association between healthy behaviours and abdominal adiposity was also examined.

DESIGN

In a cross-sectional protocol, anthropometric data were measured by trained operators while other data were collected through a structured interview.

SETTING

Three high schools in Naples, Italy.

SUBJECTS

A sample of 478 students, aged 14-17 years, was studied.

RESULTS

The proportion of adolescents who met each of the health recommendations varied: 55·4% had breakfast on ≥6 d/week; 2·9% ate ≥5 servings of fruit and vegetables/d; 1·9% had ≥3 servings of milk/yoghurt daily; 13·6% performed moderate-to-vigorous physical activity for ≥60 min/d; and 46·3% watched television for <2 h/d. More than 65% of adolescents consumed ≥1 serving of junk snack foods/d. Only 5% fulfilled at least three recommendations. Healthy habits tended to correlate with each other. As the number of health recommendations met decreased, the percentage of adolescents with high abdominal adiposity (waist-to-height ratio ≥0·5) increased. The trend was not significant when the proportion of overweight/obese adolescents was considered. Logistic regression analysis indicated that male gender and watching television for ≥2 h/d were independently associated with a higher waist-to-height ratio.

CONCLUSIONS

Most adolescents failed to meet the five health recommendations considered. Male gender and excessive television watching were associated with abdominal adiposity.

Relationship of milk intake and physical activity to abdominal obesity among adolescents

What is already known about this subject Diet and physical activity (PA) are recognized as important factors to prevent abdominal obesity (AO). Studies have found an inverse relationship between milk intake or milk products and body weight and/or body fat in children and adolescents. Evidence suggests that low levels of PA are associated with AO in youth. What this study adds Our study explored the combined association of milk intake and PA on AO in adolescents, which are most often studied in isolation. Our findings suggested that adolescents with high milk intakes, regardless of whether they were active or low active, were less likely to have AO. Our findings could have a great epidemiological interest and bring important evidence in the field of AO management among adolescents.

BACKGROUND

Diet and physical activity (PA) are recognized as important factors to prevent abdominal obesity (AO), which is strongly associated with chronic diseases. Some studies have reported an inverse association between milk consumption and AO.

OBJECTIVE

This study examined the association between milk intake, PA and AO in adolescents.

METHODS

A cross-sectional study was conducted with 1209 adolescents, aged 15-18 from the Azorean Archipelago, Portugal in 2008. AO was defined by a waist circumference at or above the 90th percentile. Adolescent food intake was measured using a semi-quantitative food frequency questionnaire, and milk intake was categorized as 'low milk intake' (<2 servings per day) or 'high milk intake' (≥2 servings per day). PA was assessed via a self-report questionnaire, and participants were divided into active (>10 points) and low-active groups (≤10 points) on the basis of their reported PA. They were then divided into four smaller groups, according to milk intake and PA: (i) low milk intake/low active; (ii) low milk intake/active; (iii) high milk intake/low active and (iv) high milk intake/active. The association between milk intake, PA and AO was evaluated using logistic regression analysis, and the results were adjusted for demographic, body mass index, pubertal stage and dietary confounders.

RESULTS

In this study, the majority of adolescents consumed semi-skimmed or skimmed milk (92.3%). The group of adolescents with high level of milk intake and active had a lower proportion of AO than did other groups (low milk intake/low active: 34.2%; low milk intake/active: 26.9%; high milk intake/low active: 25.7%; high milk intake/active: 21.9%, P = 0.008). After adjusting for confounders, low-active and active adolescents with high levels of milk intake were less likely to have AO, compared with low-active adolescents with low milk intake (high milk intake/low active, odds ratio [OR] = 0.412, 95% confidence intervals [CI]: 0.201-0.845; high milk intake/active adolescents, OR = 0.445, 95% CI: 0.235-0.845).

CONCLUSION

High milk intake seems to have a protective effect on AO, regardless of PA level.

Illness and determinants of health-related quality of life in a cross-sectional sample of schoolchildren in different weight categories

Aim: To study associations between health-related quality of life (HRQoL), frequency of illness, and weight in primary school children in southern Germany.

Methods: Data from baseline measurements of the outcome evaluation of a teacher based health promotion programme (“Join the Healthy Boat”) were analysed. Parents provided information about their children’s HRQoL (KINDL^R, EQ5D-Y Visual Analogue Scale). The number of visits to a physician, children’s days of absence because of sickness, and parental days of absence from work due to their children’s illness during the last year of school/kindergarten were queried. Children’s weight status was determined by body mass index (BMI), central obesity by waist to height ratio (WHtR ≥0.5).

Results: From 1,888 children (7.1±0.6 years), 7.8% were underweight, 82% had normal weight, 5.7% were overweight and 4.4% obese. 8.4% of all children were centrally obese. Bivariate analysis showed no significant differences for parental absence and visits to a physician in weight groups classified by BMI, but obese children had more sick days than non-obese. Centrally obese children differed significantly from the rest in the number of sick days and visits to a physician, but not in the frequency of parental absence. In regression analyses, central obesity correlated significantly with EQ5D-Y VAS, KINDL^R total score and the subscales of “psyche”, “family” and “friends”. BMI weight groups showed no significant associations.

Conclusions: Central obesity but not BMI derived overweight and obesity is associated with HRQoL and visits to a physician in primary school children. Future studies should include WHtR. Preventive measures for children should focus on a reduction of or slowed increase in waist circumference.

Physical activity growth curves relate to adiposity in adolescents

PURPOSE

Findings from prospective studies on associations between physical activity and adiposity among youth are inconsistent. Our aim was to describe physical activity trajectories during secondary school and examine the association with change in adiposity in youth.

METHODS

Physical activity was measured in 20 survey cycles from 1999 to 2005; anthropometrics were measured in survey cycles 1, 12, and 19. Individual growth curves modeling moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) were estimated. Estimates of initial level and rate of decline in MVPA and VPA bouts per week were included as potential predictors of body fat% and body mass index using age- and sex-specific linear regression.

RESULTS

Complete data were available for 840 and 760 adolescents aged 12-13 years at baseline, followed from survey cycles 1-12 and 12-19, respectively. Among girls, yearly declines of one MVPA and one VPA bout per week during earlier adolescence were associated with increases of 0.19 (95% confidence interval [CI], 0.02-0.36) and 0.47 (95% CI, 0.015-0.92) units of body fat%, respectively. In boys, a yearly decline of one MVPA bout per week was associated with an increase of 0.38 (95% CI, 0.05-0.70) units of body fat% during later adolescence.

CONCLUSIONS

Obesity prevention programs should include strategies to prevent declines in physical activity.

Is Physical Fitness Associated with Health in Overweight and Obese Youth? A Systematic Review

A systematic review of literature was conducted to examine the association between changes in health-related fitness (e.g. aerobic capacity and muscular strength /endurance) and chronic disease risk factors in overweight and/or obese youth. Studies published from 2000-2010 were included if the physical activity intervention was a randomized controlled trial and reported changes in fitness and health outcomes by direction and significance (p< 0.05) of the effect. Aerobic capacity improved in 91% and muscular fitness improved in 82% of measures reported. Nearly all studies (32 of 33) reported improvement in at least one fitness test. Changes in outcomes related to adiposity, cardiovascular, musculoskeletal, metabolic, and mental/emotional health improved in 60%, 32%, 53%, 41%, and 33% of comparisons studied, respectively. In conclusion, overweight and obese youth can improve physical fitness across a variety of test measures. When fitness improves, beneficial health effects are observed in some, but not all chronic disease risk factors.

Is central obesity associated with poorer health and health-related quality of life in primary school children? Cross-sectional results from the Baden-Württemberg Study

BACKGROUND

Childhood obesity and its consequences are a growing threat to national economies and health services. The aim of this study was to determine associations between waist-to-height ratio (WHtR) as a measure of central obesity, and health-related quality of life (HRQoL) and absenteeism of primary school children in the state of Baden-Württemberg, Germany.

METHODS

Cross-sectional data from 1888 first and second grade children (7.1±0.6 years) participating in the baseline measurements of the Baden-Württemberg Study were analyzed. Parents completed questionnaires including a rating of their children's HRQoL using KINDLR and EQ5D-Y VAS. Days of absence because of illness, and number of visits to a physician during the last year of school/kindergarten were asked, as well as the number of days parents took off work to care for their sick child. Anthropometric measurements were taken by trained staff. The Mann-Whitney-U test was used for statistical analysis of differences between WHtR groups. Logistic regression models were used to identify factors associated with sick days.

RESULTS

A total of 158 (8.4%) children were centrally obese (WHtR ≥0.5). These children had significantly more sick days (9.05 vs. 6.84, p < 0.001) and visits to a physician (3.58 vs. 2.91, p < 0.05), but not days of parental absence than other children. According to regression analysis, sick days were also associated with age, migration status, physical activity pattern, maternal health awareness and family education level. Parent-rated HRQoL was significantly lower in centrally obese children for the EQ5D-Y VAS (88.1 vs. 91.6, p < 0.001), and the KINDLR subscales 'school' (79.9 vs. 82.5, p < 0.05) and 'friends' (75.4 vs. 78.3, p < 0.05), but not for the total score.

CONCLUSIONS

Cross-sectional results show higher rates of absence, more visits to a physician and lower HRQoL in children with central obesity. Each missed day at school implies a hazard to academic achievement and each additional visit to a physician is related to higher health care costs. Thus, the negative impact of central obesity is already measurable in primary school children, which emphasizes the urgent need for early delivery of health promotion and targeted prevention.

TV viewing and obesity among Norwegian children: the importance of parental education

AIM

To analyse the effect of lifestyle factors on the prevalence of overweight and obesity in 6-15-year-old Norwegian children.

METHODS

Questionnaire data on lifestyle factors (sedentary behaviour, activity and eating habits) and prevalence numbers of overweight and obesity based on measured height and weight were analysed using multinomial logistic regression in a sample of 2281 children included in the Bergen Growth Study.

RESULTS

More screen time increased the risk of overweight (odds ratio (OR): 1.25; p = 0.02) and obesity (OR: 1.12; p = 0.02) as did the presence of a TV in the child's bedroom (OR: 1.26 (overweight), OR: 1.81 (obese); p = 0.04). The obese children reported less sugar intake than the not overweight children (OR: 0.58; p = 0.01). Higher parental education was associated with less screen time (p = 0.02), lower frequency of TV in the child's bedroom (p = 0.001), more sports (p = 0.005), as well as eating more fruit and vegetables, less sweets, soft drinks and fast food, and more regular meals (for all, p < 0.03).

CONCLUSION

Indicators of sedentary lifestyle, such as screen time and the presence of a TV in the child's bedroom, were associated with overweight and obesity in Norwegian schoolchildren. Higher parental education was generally associated with less obesogenic lifestyle.

Multidisciplinary therapy reduces risk factors for metabolic syndrome in obese adolescents

This study aims to assess the effects of a 16-week multidisciplinary program of obesity treatment on the control of metabolic syndrome (MS) and dyslipidemia in obese adolescents. Eighty-six adolescents aged 10-18 years were allocated in either the intervention group (IG; n = 44) or control group (CG; n = 42). IG was submitted to a multidisciplinary intervention based on cognitive behavioral therapy that aimed to modify eating habits and exercise behavior. We analyzed, before and after the intervention period, anthropometric parameters, body composition, bone mineral density, cardiorespiratory fitness, blood pressure, glucose, insulin, and lipid profile of the subjects. MS was classified according to International Diabetes Federation (2007) and the presence of dyslipidemia according to Back et al. (Arq Bras Cardiol 85:4-36, 2005). In the beginning of the intervention, the median number (range) of risk factors for MS present was 2.0 (0.0-5.0) in the IG and 2.0 (0.0-4.0) in the CG. After the intervention, this parameter reduced significantly in the IG (1.0 (0.0-5.0); p = 0.004) while no change was observed in the CG (2.0 (0.0-4.0); p = 0.349). In addition, we observed improvements in body mass index, waist circumference, hip circumference, maximal oxygen uptake, absolute and relative body fat, systolic blood pressure, diastolic blood pressure, and total cholesterol in the IG which was not identified in the CG. Conclusio n: We suggest that a 16-week multidisciplinary intervention based on cognitive behavioral therapy was adequate to reduce risk factors for MS in obese adolescents.

Objectively measured sedentary time, physical activity and markers of body fat in preschool children

The purpose of this study was to examine the associations between sedentary behavior and moderate to vigorous physical activity (MVPA), measured by accelerometry, with body mass index (BMI) and waist circumference in 357 preschool children. Linear mixed models were used adjusting for race/ethnicity, parental education, and preschool. Follow-up analyses were performed using quantile regression. Among boys, MVPA was positively associated with BMI z-score (b = 0.080, p = .04) but not with waist circumference; quantile regression showed that MVPA was positively associated with BMI z-score at the 50th percentile (b = 0.097, p < .05). Among girls, no associations were observed between sedentary behavior and MVPA in relation to mean BMI z-score and mean waist circumference. Quantile regression indicated that, among girls at the 90th waist circumference percentile, a positive association was found with sedentary behavior (b = 0.441, p < .05), and a negative association was observed with MVPA (b = -0.599, p < .05); no associations were found with BMI z-score. In conclusion, MVPA was positively associated with BMI z-score among boys, and MVPA was negatively associated and sedentary behavior was positively associated with waist circumference among girls at the 90th percentile.

The association between socioeconomic status and obesity in Peruvian women

Historically in developing countries, the prevalence of obesity has been greater in more advantaged socioeconomic groups. However, in recent years the association between socioeconomic status (SES) and obesity has changed and varies depending on the country's development stage. This study examines the relationship between SES and obesity using two indicators of SES: education or possession assets. Using the cross-sectional 2008 National Demographic and Family Health Survey of Peru (ENDES 2008), we investigated this relationship in women aged 15-49 years living in rural and urban settings. Descriptive, linear and logistic regressions analyses were conducted accounting for the multistage nature of the sampling design. The overall prevalence of obesity in this study was 14.1% (95% confidence interval (CI): 13.3-14.8); 8.4% (95% CI: 7.5-9.3) in rural areas and 16.2% (95% CI: 15.2-17.2) in urban areas. Wealthier women were more likely to be obese, and this association was stronger in rural areas. Conversely, more educated women were less likely to be obese, especially in urban areas. The distribution of obesity in Peruvian women is strongly related to socioeconomic position, and differs whether measured as possession assets or by level of education. These findings could have important implications for policy development in Peru.

Oxidative stress as pathogenesis of cardiovascular risk associated with metabolic syndrome

Metabolic syndrome (MetS) is characterized by accumulation of visceral fat associated with the clustering of metabolic and pathophysiological cardiovascular risk factors: impaired glucose tolerance, dyslipidemia, and hypertension. Although the definition of MetS is different among countries, visceral obesity is an indispensable component of MetS. A growing body of evidence suggests that increased oxidative stress to adipocytes is central to the pathogenesis of cardiovascular disease in MetS. Increased oxidative stress to adipocytes causes dysregulated expression of inflammation-related adipocytokines in MetS, which contributes to obesity-associated vasculopathy and cardiovascular risk primarily through endothelial dysfunction. The purpose of present review is to unravel the mechanistic link between oxidative stress and cardiovascular risk in MetS, focusing on insulin resistance, hypertension, and atherosclerosis. Then, therapeutic opportunities translated from the bench to bedside will be provided to develop novel strategies to cardiovascular risk factors in MetS.

Effects of resistance training and aerobic exercise on insulin sensitivity in overweight korean adolescents: a controlled randomized trial

BACKGROUND

Data on the impact of resistance training on insulin resistance in overweight or obese children are inconclusive.

METHODS

Thirty overweight South Korean adolescents (mean age of 13.10 years) were divided by sex, and then randomly assigned to one of three treatment groups, which were the diet only (DO), diet with aerobic exercise (AE), or diet with resistance training (RT) group. Physiologic and metabolic parameters were assessed at baseline and after 12 weeks of exercise training and diet modification.

RESULTS

Both exercise groups (aerobic and resistance) showed significant improvements in their insulin area under the curve and insulin sensitivity index values when compared to their baseline values while the DO group showed no significant changes in these variables. Age-, sex-, and body mass index (BMI)-adjusted intergroup comparison analyses showed a marked reduction in BMI and a significant reduction in muscle mass in the AE group when compared to the RT group and the DO group, respectively.

CONCLUSION

A 12-week exercise training program of either resistance or aerobic activity improved insulin sensitivity in overweight adolescents, although it failed to show superiority over a DO program. Aerobic exercise decreased both body weight and BMI, and it was noted that this group also had a significant reduction in muscle mass when compared to the DO group.

Management of metabolic syndrome in children and adolescents

Concomitantly with the increasing prevalence of childhood obesity, the prevalence of metabolic syndrome (MS) is rising among children and adolescents, leading to fears for future epidemics of type 2 diabetes mellitus and cardiovascular disease in the young. This makes the accurate identification and the appropriate treatment of children and adolescents with MS an important priority for health care systems. This review will focus on the management of each component of MS, including the nonalcoholic fatty liver disease (NAFLD), which is currently considered as the hepatic component of the syndrome. The most relevant target of treatment of MS in children and adolescents is the abdominal obesity. To this end, we will discuss the efficacy of dietary approaches, possibly coupled with regular physical activity, on eliciting visceral fat reduction. We will also highlight several aspects of the treatment of the high triglyceride/low high-density lipoprotein cholesterol phenotype, including the use of non-pharmacological measures, and indications for instituting drug therapies. Part of this review will address treatment of glucose abnormalities, including the benefits of lifestyle modification alone, and the potential adjunctive role of hypoglycemic drugs. The treatment of hypertension in children with MS also requires a multifaceted approach and the available data of this topic will be examined. The remainder of this review will address treatment to reverse NAFLD and prevent progression to end-stage disease.

Physically active academic lessons in elementary children

BACKGROUND

Although schools are an ideal location to conduct interventions that target children, the emphasis on standardized testing makes it difficult to implement interventions that do not directly support academic instruction. In response, physically active academic lessons have been developed as a strategy to increase physical activity while also addressing core educational goals. Texas I-CAN! is one incarnation of this approach.

METHODS

We will review the on-going research on the impact of these active lessons on: teacher implementation, child step count, child attention control, and academic performance.

RESULTS

The collected studies support the impact of physically active academic lessons on each area of interest.

CONCLUSIONS

If these data can be replicated, it suggests that teachers might find these lessons of benefit to their primary role as educators, which should ease dissemination of these and other physically active lessons in elementary schools.

Moving beyond the stigma: systematic review of video games and their potential to combat obesity

Increasing epidemic proportions of overweight children in the United States presents formidable challenges for education and healthcare. Given the popularity and pervasiveness of video gaming culture in North American children, the perfect opportunity arises to investigate the potential of video games to promote healthful behaviour. Our objective was to systematically review the literature for possible benefits of active and educational video games targeting diet and physical activity in children. A review of English-language journal articles from 1998 to 2011 using EMBASE and PubMed was conducted. Thirty-four studies concerned with children, video games, physical, and/or nutritional outcomes were included. Results of these studies that showed some benefit (increased physical activity and nutritional knowledge as a result of gaming) demonstrate the possibility of video games to combat childhood obesity—looking beyond the stigma attached to gaming.

Heart disease and stroke statistics--2011 update: a report from the American Heart Association

Each year, the American Heart Association (AHA), in conjunction with the Centers for Disease Control and Prevention, the National Institutes of Health, and other government agencies, brings together the most up-to-date statistics on heart disease, stroke, other vascular diseases, and their risk factors and presents them in its Heart Disease and Stroke Statistical Update. The Statistical Update is a valuable resource for researchers, clinicians, healthcare policy makers, media professionals, the lay public, and many others who seek the best national data available on disease morbidity and mortality and the risks, quality of care, medical procedures and operations, and costs associated with the management of these diseases in a single document. Indeed, since 1999, the Statistical Update has been cited more than 8700 times in the literature (including citations of all annual versions). In 2009 alone, the various Statistical Updates were cited ≈1600 times (data from ISI Web of Science). In recent years, the Statistical Update has undergone some major changes with the addition of new chapters and major updates across multiple areas. For this year’s edition, the Statistics Committee, which produces the document for the AHA, updated all of the current chapters with the most recent nationally representative data and inclusion of relevant articles from the literature over the past year and added a new chapter detailing how family history and genetics play a role in cardiovascular disease (CVD) risk. Also, the 2011 Statistical Update is a major source for monitoring both cardiovascular health and disease in the population, with a focus on progress toward achievement of the AHA’s 2020 Impact Goals. Below are a few highlights from this year’s Update.

Epidemiology of abdominal obesity among adolescents from a Brazilian State Capital

The objective of this study was to investigate the effects of socioeconomic, demographic and lifestyle factors on abdominal obesity in adolescents from a Brazilian state capital. In this cross-sectional study, 656 high school students (423 girls and 233 boys) from public schools, ranging in age from 14 to 19 yr, were evaluated. Abdominal obesity was identified based on waist circumference. Socioeconomic data (socioeconomic status, household head's education, and school grade), demographic data (gender and age), and information regarding lifestyle (physical activity, eating habits, aerobic fitness, and nutritional status) were collected. Logistic regression was used for multivariate analysis. The prevalence of abdominal obesity was 6.6% (95% confidence interval [CI]: 4.6-8.4). Being in the second (odds ratio [OR] = 0.41; 95% CI: 0.19-0.88) or third year (OR = 0.18; 95% CI: 0.06-0.59) of high school was a protective factor against abdominal obesity. In addition, students presenting low aerobic fitness (OR = 4.10; 95% CI: 1.62-10.4) and those with excess weight (OR = 208.6; 95% CI: 47.7-911.7) had a higher probability of abdominal obesity. In conclusion, demographic factors such as school grade, lifestyle habits, low aerobic fitness and excess weight are associated with central obesity.

The role of anorexigenic and orexigenic neuropeptides and peripheral signals on quartiles of weight loss in obese adolescents

Obesity is characterized as an inflammatory state associated with a modification in the pattern of adipokine secretion. The present study aimed to assess the role of anorexigenic and orexigenic neuropeptides and peripheral signals in obese adolescents submitted to 1 year of weight loss interdisciplinary therapy and grouped according to quartiles of weight loss. A total of 111 post-puberty adolescents, with a BMI >95th percentile, were included. Glycemia and lipid profiles were analyzed. Insulin resistance was estimated by HOMA-IR. Cytokine concentrations were measured by ELISA. The results are presented according to quartiles of weight loss: 1st (<2.5 kg)=low; 2nd (2.5-8 kg)=low to moderate; 3rd (8-14 kg)=moderate; and 4th (>14 kg)=massive. The most important finding was that the NPY concentration increased significantly only in the first phase of weight loss. Moreover, α-MSH variation was an independent factor in explaining the NPY changes during the intervention, confirming the role of the α-MSH concentration in the peripheral control of energy balance in obese adolescents. Indeed, BMI reduction was correlated with increased α-MSH (p<0.05). Massive weight loss promoted a significant increase in α-MSH concentration, and hyperleptinemia was reduced after intervention. All together, our findings, which contribute to our understanding of how orexigenic and anorexigenic systems are regulated by weight loss, will provide insight into the pathogenesis and treatment of obesity and other metabolic diseases, especially in obese adolescents.