Function In Obese Adolescents Research Articles

An assessment of renal function by neutrophil lipocalin and cystatin C in obese adolescents with or without obesity-induced hypertension

Introduction: Obesity and hypertension are associated with organ complications, including kidney diseases. It is necessary to search for the methods of early detection of these complications. Aim: The aim of the study was to assess renal function in obese adolescents, based on lipocalin-2 and cystatin C levels in relation to creatinine, estimated glomerular filtration rate and leptin levels. Materials and methods: The study included 76 children aged 11–17 years, with obesity or with obesity and obesity- induced hypertension or normosthenic children with tension headaches (control group). Renal function was assessed based on serum creatinine and estimated glomerular filtration rate (Schwartz equation). Plasma and urine lipocalin-2, serum cystatin C and leptin levels were determined by ELISA. Results: Renal function assessed by creatinine level and estimated glomerular filtration rate was normal in all patients, but mean creatinine levels were significantly higher and estimated glomerular filtration rate was significantly lower in the study groups compared to controls. No significant differences were found in plasma and urine lipocalin-2 levels. Mean cystatin C level was significantly higher in the obese group. We have found a weak positive correlation between plasma lipocalin-2 and creatinine levels and its weak negative correlation with estimated glomerular filtration rate, as well as a positive correlation for leptin and cystatin C levels in the obese group. Conclusion: The role of plasma and urine lipocalin-2 and serum cystatin C in the assessment of renal function in obese adolescents with or without obesity-induced hypertension is ambiguous. The relationship between cystatin C and leptin levels in obese children also requires further research.

High-Intensity Interval Exercise with Blood Flow Restriction Improves Vascular Function in Obese Male Adolescents

Study purpose. Obesity, a chronic metabolic disease is on the rise among children and adolescents and is a leading cause of mortality in adults worldwide. It is imperative to prevent obesity in children to lower the risk of adult obesity and cardiovascular diseases. Considering the effectiveness of exercise program, high-intensity interval exercise with blood flow restriction (HIIE-BFR) may have potential beneficial effects on the vascular functions of obese individuals. This study aimed to compare the acute effects of supramaximal high-intensity interval exercise (HIIE-SUPRA) and HIIE-BFR on the vascular function in obese adolescents. Materials and methods. The subjects were adolescent males aged 13 to 15. The crossover study was divided into two trials. The first trial was a pilot study involving five obese adolescent males whose heart rates were evaluated under four conditions of exercise: 1) HIIE-SUPRA at 170% (VO₂peak), 2) HIIE-BFR at 85% VO₂peak with 40% arterial occlusion pressure (AOP), 3) 60% AOP, and 4) 80% AOP. The second trial was conducted on ten obese adolescent males who performed HIIE-SUPRA and HIIE-BFR exercises separately, each for at least three days. Data collection was done to analyze the vascular function parameters before and after exercising (immediately, 10 min, 30 min, and 60 min after). Results. The results of the first trial showed that the mean heart rate of HIIE-BFR at 40% AOP was similar to that of HIIE-SUPRA (p>0.05). In the second trial, both types of exercises showed similar outcomes, with increased flow-mediated dilatation (FMD), while brachial-ankle pulse wave velocity (baPWV) decreased after exercise as compared to the baseline values (before exercise) (p<0.05). However, HIIE-BFR at 40% AOP demonstrated a lower rate of perceived exertion (RPE) as compared to HIIE-SUPRA (p<0.05). Conclusions. HIIE-BFR at 40% AOP was effective in regulating the RPE and acutely increasing the vascular function after exercise in obese adolescents, similar to HIIE-SUPRA.

Circadian Rhythm of Salivary Cortisol in Obese Adolescents With and Without Apnea: A Pilot Study.

Background and ObjectiveObstructive sleep apnea (OSA) and obesity are associated with stress system activation involving the hypothalamic-pituitary-adrenal (HPA) axis in adults, but these effects in childhood and adolescence remain unclear. We examined diurnal salivary cortisol as a measurement of the HPA axis function in obese adolescents with and without OSA and the relationships between cortisol levels, body weight, and parameters of polysomnography (PSG).MethodsAfter PSG, saliva samples were collected from obese participants (with and without OSA) and lean participants four times over a 24-h period, namely, at 7:00 h (m-sCort), 13:00 h (a-sCort), 19:00 h (e-sCort), and 23:00 h (n-sCort). An enzyme-linked immunosorbent assay (ELISA) was used to measure salivary cortisol levels. The mean values of cortisol levels and fixed-time point diurnal cortisol slope (DCS) were calculated and compared among the three study groups. Correlations between parameters were analyzed using Spearman's correlation coefficients.ResultsObese OSA participants had significantly higher e-sCort and n-sCort levels than both obese non-OSA participants and lean controls. However, m-sCort and a-sCort in these patients had a pronounced upward trend. M-sCort was significantly correlated with both the lowest oxygen saturation (SpO2) and time with SpO2 <90%. Moreover, in the obese OSA group, DCS was significantly flatter than in the other two groups. The a-sCort in obese non-OSA participants was significantly higher than that in the lean control group and, surprisingly, was positively correlated with the apnea/hypopnea index. Additionally, m-sCort was related to body weight.ConclusionThis study provided further evidence for alterations in diurnal cortisol production in obese adolescents, which may indicate a chronically stressed HPA axis. However, there were significant differences in salivary cortisol parameters between participants with and without OSA. Furthermore, patients with OSA had more associations between time-point cortisol levels and OSA-related indices. Nonetheless, this research is a pilot study, and further investigations are necessary.

Критерии прогрессирования стеатогепатоза у подростков с ожирением и признаками метаболического синдрома

Актуальность. На сегодняшний день ожирение у подростков — актуальная проблема, обусловленная как распространенностью данной патологии, прежде всего в развитых странах, так и возможными последствиями в будущем, в частности развитием метаболического синдрома. Считалось, что метаболический синдром диагностируется у людей среднего и пожилого возраста, но современные исследования свидетельствуют о том, что эта патология все чаще проявляется у подростков, и ключевым органом патогенеза всех метаболических расстройств является печень. Цель: создание критериев ранней диагностики фиброгенеза при стеатогепатозе у подростков с ожирением. Материалы и методы. Обследованы 226 больных ожирением в возрасте 12–18 лет. Для оценки функционального состояния печени использованы клинико-лабораторные и инструментальные методы исследования. В качестве критерия инсулинорезистентности применялась гомеостатическая модель НОМА-IR (Homeostasis model assessment). Также методом иммуноферментного анализа определялись в сыворотке крови уровни фибронектина, коллагена IV типа, N-терминальных пропептидов и С-терминальных телопептидов коллагена I типа. Для определения критериев диагностики стеатогепатоза у подростков была использована неоднородная последовательная процедура Вальда — Генкина. Результаты. Полученные результаты основных исследований (лабораторных и инструментальных) у подростков с ожирением демонстрируют наличие нарушений функционального состояния печени, проявляющихся в форме стеатогепатоза. Выявленные нарушения липидного спектра крови атерогенного характера, инсулинорезистентность, абдоминальный тип ожирения позволили выделить группы риска по развитию метаболического синдрома у этих подростков. Изучено диагностическое значение биохимических маркеров фиброза при неалкогольной жировой болезни печени. Разработанные критерии прогрессирования стеатогепатоза у подростков с ожирением и признаками метаболического синдрома подтвердили диагностическую значимость и надежность, что будет способствовать своевременному лечению и профилактике осложнений. Выводы. В перспективе использование разработанного алгоритма позволит повысить эффективность ранней диагностики жировой болезни печени и усовершенствовать лечебно-профилактические мероприятия.

Acute coordinative exercise ameliorates general and food-cue related cognitive function in obese adolescents

ABSTRACTWhether the acute coordinative exercise could affect the inhibitory control and food-cue related attention in obese adolescents remains understudied. Therefore, this study used the Stroop test and the food-cue related Stroop test to explore the impacts of 20 min of acute coordinative exercise on the cognitive tests involving inhibitory control and attentional bias towards food-cue related stimuli, respectively, in obese adolescents. Thirty-eight obese adolescents (mean age = 14.63 ± 0.69 years) were equally divided into exercise and control groups. The cognitive tests (i.e., the Stroop test and the food-cue related Stroop test) and hunger scores were conducted and assessed before and after an intervention. The exercise group had significantly larger negative pre-post response time difference in the congruent (−1.04 ± 0.29 ms) and incongruent (−5.76 ± 1.66 ms) conditions of the Stroop test than the control group (ps < 0.01), and a smaller post-interference (1.13 ± 0.14) than the pre-interference (1.31 ± 0.14, p = 0.04). Moreover, a significantly larger negative pre-post response time difference on the food-cue related Stroop test was observed in the exercise group (−4.42 ± 7.20 ms) than the control group (1.76 ± 8.37 ms, p = 0.02). Collectively, an acute coordinative exercise session could induce superior inhibitory control and less attentional bias towards food-cue related stimuli in obese adolescents.

Exceptional reported effects and data anomalies merit explanation from “A randomized controlled trial of coordination exercise on cognitive function in obese adolescents” by Liu et al. (2018)

We read the article in Psychology of Sport and Exercise by Liu et al. (“A randomized controlled trial of coordination exercise on cognitive function in obese adolescents”) with great interest. Our interest in the article stemmed from the extraordinary differences in obesity-related outcomes reported in response to a rope-jumping intervention. We requested the raw data from the authors to confirm the results and, after the journal editors reinforced our request, the authors graciously provided us with their data. We share our evaluation of the original data herein, which includes concerns that weight and BMI loss by the intervention appears extraordinary in both magnitude and aspects of the distributions. We request that the authors address our findings by providing explanations of the extraordinary data or correcting any errors that may have occurred in the original report, as appropriate.

Conducting exercise trials for obese adolescents within the effectiveness setting: A response with commentary to Ejima et al. (2019)

We appreciate Ejima et al.‘s interest in and comments towards our article describing a 12-week randomized controlled trial of a coordination exercise program on cognitive function in obese adolescents that was conducted at a junior high school in Taipei City, Taiwan (Liu et al., 2018). Ejima et al. mentioned the apparent extraordinary effects of the interv ention on body mass index (BMI) both in the magnitude of the effects and distribution of the weight loss. On several points, we agree with Ejima et al. and in the spirit of transparency and reproducibility, we appreciate the opportunity to set the record straight about our study. We also genuinely appreciate Ejima et al.‘s time and efforts in reviewing our study and analyzing the data, and helping to uncover these mistakes. We hope this commentary aids in better understanding the findings from Liu et al. (2018) and in encouraging future effectiveness trials aimed at improving cognitive function, fitness, and BMI among obese adolescents.

Cardiac function in adolescents with obesity: cardiometabolic risk factors and impact on physical fitness.

To gain greater insights in the etiology and clinical consequences of altered cardiac function in obese adolescents. Therefore,we aimed to examine cardiac structure and function in obese adolescents, and to examine associations between altered cardiac function/structure and cardiometabolic disease risk factors or cardiopulmonary exercise capacity. In 29 obese (BMI 31.6 ± 4.2 kg/m², age 13.4 ± 1.1 years) and 29 lean (BMI 19.5 ± 2.4 kg/m², age 14.0 ± 1.5 years) adolescents, fasted blood samples were collected to study hematology, biochemistry, liver function, glycemic control, lipid profile, and hormones, followed by a transthoracic echocardiography to assess cardiac structure/function, and a cardiopulmonary exercise test (CPET) to assess cardiopulmonary exercise parameters. Regression analyses were applied to examine relations between altered echocardiographic parameters and blood parameters or CPET parameters in the entire group. In obese adolescents, left ventricular septum thickness, left atrial diameter, mitral A-wave velocity, E/e' ratio were significantly elevated (p < 0.05), as opposed to lean controls, while mitral e'-wave velocity was significantly lowered (p < 0.01). Elevated homeostatic model assessment of insulin resistance and blood insulin, c-reactive protein, and uric acid concentrations (all significantly elevated in obese adolescents) were independent risk factors for an altered cardiac diastolic function (p < 0.01). An altered cardiac diastolic function was not related to exercise tolerance but to a delayed heart rate recovery (HRR; p < 0.01). In obese adolescents, an altered cardiac diastolic function was independently related to hyperinsulinemia and whole-body insulin resistance, and only revealed by a delayed HRR during CPET. This indicates that both hyperinsulinemia, whole-body insulin resistance, and delayed HRR could be regarded as clinically relevant outcome parameters.

Effects of Exercise Intensity on Microvascular Function in Obese Adolescents.

The optimal exercise modality for the improvement of health-related parameters and microvascular function in obese adolescents is not yet fully understood. Therefore, this study aimed to 1) compare the microvascular phenotype of obese and normal-weight adolescents; and 2) to determine the effects of a lifestyle intervention including three months of moderate continuous training (MCT) or high-intensity interval training (HIIT) on health-related parameters and microvascular function in 29 obese adolescents. Body composition, metabolic profile, aerobic fitness and cutaneous blood flow, measured using laser Doppler flowmetry at rest and during post-occlusive reactive hyperemia, were assessed prior to and following lifestyle intervention. Sixteen normal-weight adolescents were included as reference controls for baseline microvascular parameters. At baseline, obese adolescents had higher peak blood flow, peak vascular conductance and area under the curve for post-occlusive reactive hyperemia than normal-weight adolescents. Conversely, peak blood flow, peak vascular conductance and area under the curve data remained unchanged after MCT and HIIT without intergroup differences. However, the peak/basal blood flow ratio decreased in both MCT and HIIT groups without any interaction between groups due to basal CBF increase (tendency p=0.074). Exercise training, whatever the modality, does not improve peak microcirculatory function.

Health behavior associated with liver enzymes among obese Korean adolescents, 2009-2014.

AimsObesity is major risk factor for liver health. This study aimed to clarify whether specific health behaviors were associated with liver function in obese adolescents in Korea.MethodsBased on national school health examination data from 2009 to 2014, 25,142 obese or overweight students were examined for aspartate transaminase and alanine transaminase levels, and health behaviors. Multiple logistic regression was used to calculate the odds ratio for liver enzyme elevation.ResultsSubjects who thought of themselves as “very fat” had a 1.6 times higher odds ratio for liver enzyme elevations than those who thought of themselves as “normal.” Those who consumed fast food 3 to 5 times weekly had 1.3 times higher odds ratio (OR = 1.27, 95% confidence interval = 1.05–1.54) for the elevation of ALT than those who did not consume fast food. Those who took sugar-sweetened beverage 3 to 5 times weekly had 1.2 times higher odds ratio (OR = 1.24, 95% confidence interval = 1.07–1.42) for the elevation of ALT than those who did not take it. Those who played computer game more than 2 hours a day showed 1.1 times higher odds ratio (OR = 1.10, 95% confidence interval = 1.01–1.21) for the elevation of ALT than those who did not.ConclusionsSpecific food item and its frequency of consumption were identified for the positive and negative association with the elevation of liver enzymes. Self-image of body shape, sleeping time and need of help for alcohol or smoking problems also showed substantial association with the elevation.

Aerobic exercise improves endothelial function and serum adropin levels in obese adolescents independent of body weight loss

Adropin is a secreted protein that regulates endothelial function. However, adropin levels in obese adolescent patients are currently uncertain. Therefore, we evaluated the association between plasma adropin levels and vascular endothelial function and investigated the effect of aerobic exercise in obese adolescents. A total of 45 obese adolescents and 20 controls (age 16–19 years) were included in our study. The obese adolescents received 12 weeks of aerobic exercise training. Serum adropin was detected using enzyme-linked immunosorbent assay. Vascular reactive hyperemia indexes (RHIs) were obtained using Endo-PAT2000. Adropin levels and RHI were significantly lower in obese adolescents than in normal-weight adolescents. Adropin levels and RHI increased significantly independently of changes in body weight after an exercise intervention (P < 0.01). Pearson correlation analysis revealed that adropin levels positively correlated with HDL-C levels (r = 0.389, P < 0.01) and RHI (r = 0.32, P < 0.01). Multiple linear stepwise regression analysis showed that the insulin resistance index (t = −3.301, P < 0.01) and HDL-C level (t = 2.620, P = 0.011) were independent risk factors of adropin levels. In addition, Δadropin (t = 3.261, P < 0.01) was an independent influencing factor of ΔRHI. Our findings suggest that adropin plays an important role in vascular endothelial function in obese adolescents.

Upper Gastrointestinal Function in Morbidly Obese Adolescents Before and 6Months After Gastric Banding.

The effects of laparoscopic adjustable gastric band (LAGB) placement on upper gastrointestinal tract function in obese adolescents are unknown. Therefore, our aim was to determine the short-term effects of LAGB on esophageal motility, gastroesophageal reflux, gastric emptying, appetite-regulatory hormones, and perceptions of post-prandial hunger and fullness. This study was part of a prospective cohort study (March 2009-December 2015) in one tertiary referral hospital. The study included obese adolescents (14-18years) with a body mass index (BMI)>40 (or ≥35 with comorbidities). Gastric emptying was assessed by 13C-octanoic acid breath test, pharyngeal, and esophageal motor function by high-resolution manometry with impedance (HRIM), and appetite and other perceptions using 100-mm visual analogue scales. Dysphagia symptoms were scored using a Dakkak questionnaire. Data were compared pre- and post-LAGB placement and at a 6-month follow-up. Based upon analysis of 15 adolescents, at the 6-month follow-up, LAGB placement: (i) led to a significant reduction in weight and BMI; (ii) increased fullness and decreased hunger post-meal; (iii) increased symptoms of dysphagia after solid food; and, despite these effects, (iv) caused little or no changes to appetite hormones, while (v) effects on gastric emptying, esophageal motility, esophageal bolus transport, and esophageal emptying were not significant. In adolescents, LAGB improved BMI and altered the sensitivity to nutrients without significant effects on upper gastrointestinal tract physiology at the 6-month follow-up.

A randomized controlled trial of coordination exercise on cognitive function in obese adolescents

ObjectiveWhether the beneficial effect of coordination exercise on executive function extends to obese adolescents remains understudied and no study to date has examined the effect of exercise on food-cue related executive function. The aim of this randomized controlled trial was to investigate the effects of a coordination exercise program on executive function in obese adolescents. DesignA randomized controlled trial. MethodsEighty obese adolescents were randomly assigned to a 12-week coordination exercise program or a waitlist control group and data from 70 participants (n = 35 for each group) were analyzed. The after-school exercise program involving a multifaceted moderate-intensity jump rope program performed twice weekly for 75 min per session. The primary outcome of normal and food-cue related Stroop task performance was assessed prior to and following the intervention. Secondary outcomes included physical fitness and body mass index (BMI). ResultsThe coordination exercise intervention improved both normal and food-cue related cognitive function. Similar beneficial effects were also found for physical fitness and BMI. However, pre-to-post intervention change in physical fitness and BMI did not significantly mediate enhanced cognitive and executive function performance. ConclusionIn obese adolescents, a coordination exercise intervention is an effective approach to improve multiple aspects of cognitive function while enhancing physical fitness and reducing obesity. These findings also suggest a possible role of cognitive inhibition in exercise-associated weight loss among obese adolescents.

High sensitivity C-reactive protein, left ventricular mass, and systolic function in obese adolescents

Background Obesity has been associated with structural and functional cardiac muscle defects. High sensitivity C-reactive protein (hs-CRP) has been utilized as an independent predictor of future cardiovascular disease.Objective To assess for correlations between hs-CRP, left ventricular mass, and systolic function in obese adolescents.Methods This cross-sectional study was conducted from August 2013 to February 2014. Subjects were obese adolescents aged 13-18 years with a body mass index (BMI) &gt;95th percentile, according to the 2000 Centers for Disease Control and Prevention Growth Chart. Subjects underwent laboratory testing of serum hs-CRP levels, as well as left ventricular mass and function measurements by echocardiography. Descriptive analysis was performed on patients’ characteristics and correlation analysis was done by Pearson’s test with a significance level of P&lt;0.05.Results Subjects were 40 obese adolescents. There was no statistically significant correlation between hs-CRP and left ventricular mass (r=0.083; P=0.305). There was a moderate correlation between hs-CRP with ejection fraction (EF) (r=0.372 and P=0.009 ) and fractional shortening (FS) of the left ventricle (r=0.420 and P=0.003).Conclusion In obese adolescents, we find no correlation between hs-CRP and left ventricular mass. However, hs-CRP is moderately correlated with left ventricular EF and FS.

Health markers in obese adolescents improved by a 12-week recreational soccer program: a randomised controlled trial

The effects of a recreational soccer program (RSP) upon body composition, heart rate variability (HRV), biochemical markers, cardio-respiratory fitness, and endothelial function in obese adolescents were investigated. A randomised controlled clinical trial was conducted with 30 adolescents aged 12–17 years and body mass index (BMI) >2 standard deviations of WHO reference values, which were assigned to RSP (n = 10, 2 girls) and obese control (n = 10, 4 girls) groups. The 12-week RSP included 60-min sessions performed 3 times/week. BMI, waist circumference, blood pressure, blood glucose, lipid profile, insulin, C-reactive protein, HRV, and maximal oxygen consumption (VO2peak) were evaluated following standardised procedures. Body composition was determined by dual-energy X-ray absorptiometry and endothelial function by venous occlusion plethysmography. After intervention, RSP exhibited significant reductions in BMI (−0.7 ± 0.2 kg · m–2), waist circumference (−8.2 ± 1.4 cm), %body fat (−2.2 ± 0.4%), systolic blood pressure (−5.0 ± 2.3 mmHg), total cholesterol (−16.2 ± 5.8 mg · dL−1), triglycerides (−20.5 ± 12.9 mg · dL−1), C-reactive protein (−0.06 ± 0.01 mg · dL−1), insulin resistance (HOMA-IR, −1.4 ± 0.6), and sympathetic activity (LF, −13.9 ± 6.6 un) vs. controls (P < 0.05). Significant increase was observed in parasympathetic activity (HF, 13.9 ± 6.6 un), VO2peak (7.9 ± 2.8 ml · kg−1 · min−1), and high-density lipoprotein cholesterol (11.0 ± 6.3 mg · dL−1) (P < 0.05). Vascular conductance (19.5 ± 8.1 ml · min−1 · 100 ml, P = 0.005) increased and vascular resistance (−5.9 ± 2.4 ml · min−1 · 100 ml, P = 0.041) decreased in RSP, but not in controls. A 12-week recreational soccer intervention was effective to improve biochemical, cardiovascular, and fitness health markers in obese adolescents.

Cholecalciferol Supplementation Does Not Influence β-Cell Function and Insulin Action in Obese Adolescents: A Prospective Double-Blind Randomized Trial ,

There is increasing interest in the extraskeletal effects of vitamin D, particularly in the obese state with regard to the development of insulin resistance and diabetes. The objective of the study was to determine the effect of 2 doses of cholecalciferol (vitamin D3) supplementation on insulin action (Si) and pancreatic β-cell function in obese adolescents. We performed a 12-wk double-blind, randomized comparison of the effect of vitamin D3 supplementation on Si and β-cell function in obese Caucasian adolescents (body mass index > 95(th) percentile). The subjects were randomly assigned to receive either 400 IU/d (n = 25) or 2000 IU/d (n = 26) of vitamin D3. Each subject underwent a 7-sample 75 g oral glucose tolerance test, with glucose, insulin, and C-peptide measurements, to calculate Si and β-cell function as assessed by the disposition index (DI), with use of the oral minimal model before and after supplementation. A total of 51 subjects aged 15.0 ± 1.9 y were enrolled. Included for analysis at follow-up were a total of 46 subjects (20 male and 26 female adolescents), 23 in each group. Initial serum 25-hydroxyvitamin D [25(OH)D] was 24.0 ± 8.1 μg/L. There was no correlation between 25(OH)D concentrations and Si or DI. There was a modest but significant increase in 25(OH)D concentration in the 2000 IU/d group (3.1 ± 6.5 μg/L, P = 0.04) but not in the 400 IU/d group (P = 0.39). There was no change in Si or DI following vitamin D3 supplementation in either of the treatment groups (all P > 0.10). The current study shows no effect from vitamin D3 supplementation, irrespective of its dose, on β-cell function or insulin action in obese nondiabetic adolescents with relatively good vitamin D status. Whether obese adolescents with vitamin D deficiency and impaired glucose metabolism would respond differently to vitamin D3 supplementation remains unclear and warrants further studies. This trial was registered at clinicaltrials.gov as NCT00858247.

Hepatic function in obese adolescents and the relationship with hepatic steatosis

Introduction : The prevalence of obesity has increased at an impressive rate over the past years, especially among children and adolescents. Many are the alterations that may be found in obese individuals; hepatic steatosis is one of them. The aim of this study was to analyze biochemical and radiographic parameters in overweight and obese adolescents and relate these parameters to anthropometric data so that the hepatic dysfunction could be characterized. Methods : Anthropometric and laboratory data, as well as the nutritional status of the patients, were evaluated. Besides laboratory exams, a liver ultrasound scan was performed to confirm hepatic alterations. Results : A total of 41 patients were recruited and 6 out of that total were excluded due to the fact they were eutrophic. The remaining group was compared with a control group of 12 patients. The overweight/obese group had higher values of AST and ALT in relation to the control group. There were no alterations associated with biochemical parameters regarding anthropometric variables. A significant difference between the BMI of patients with and without steatosis could be observed. Conclusions : There was a predominance of hepatic steatosis in the overweight/obese group, which was associated with the increase in GGT and ALT levels.

The Feasibility of High-Intensity Interval Exercise in Obese Adolescents

Exercise is a critical component in the management of pediatric obesity. Currently, continuous aerobic exercise (AE) is the standard of care for pediatric weight management programs. The 2008 Physical Activity Guidelines for Americans primarily promote aerobic activity for children, and aerobic-based exercise at a steady intensity (AE) is typically prescribed in pediatric weight management programs1. Several studies in adults, however, show advantages of high-intensity interval exercise (HIIE) over continuous A Eat improving fitness and health in both healthy and obese people2–4. These benefits of HIIE compared to AE have also been demonstrated in some limited studies in children. In a sample of healthy prepubescent children, Borel et al showed the immediate effects on oxygen uptake (VO2) of HIIE to be comparable to continuous AE by continuously monitoring gas exchange of subjects at various points in an exercise protocol Farpour et al showed improved health and fitness measures in healthy children as a result of HIIE5,6. Some of this work in children extends into the obese population. Ingul et al showed that impaired cardiac function in obese adolescents can be improved by 3 months of HIIE training on a treadmill twice a week for 13 weeks7. Tjonna et al studied obese adolescents in twice weekly HIIE intervention for 12 weeks compared to subjects receiving bimonthly education from multidisciplinary health professionals8. HIIE was superior to educational classes at improving subject BMI, body fat, blood pressure, blood glucose, and endothelial function. A study from the Sao Paulo School of Medicine compared HIIE and AE in obese 8–12 year old children with treadmill training protocols twice a week for 12 weeks. Both were found to be equally effective in improving aerobic fitness, insulin sensitivity, and BMI in obese children but the study may have had too few enrolled to show a difference between modes of exercise9. While these few studies of HIIE in obese children have shown benefits on fitness and cardiovascular risk factors, the acceptability and enjoyment of this protocol in children is not clear. Enjoyment of the exercise is a crucial component if our goal is long-term adherence. Another limitation of many HIIE studies in children is restriction of the interval training to treadmill protocols; a more varied exercise protocol would be more comparable to the current standard of care, which includes group games and more variable equipment choices. The purpose of this HIIE study was to measure the enjoyment and acceptability of HIIE as well as the feasibility of a multimodal protocol in obese teenagers enrolled in a multi-disciplinary pediatric weight management program as a precursor for a larger, definitive study.

Fat cell size and adipokine expression in relation to gender, depot, and metabolic risk factors in morbidly obese adolescents

ObjectiveTo understand the regulation of adipocyte size and adipokine expression in relation to gender, anatomic location, adiposity, and metabolic risk factors in adolescents with morbid obesity.Design and MethodsAdipocyte size and adipokine expression in paired abdominal subcutaneous (SAT) and omental (VAT) surgical adipose tissues were related to gender, anatomic location, adiposity, and metabolic risk factors in a group of morbidly obese adolescents.ResultsSignificant depot- and/or gender-related differences in adipocyte size and adipokine expression were detected. Adjusted for BMI, adipocyte size in both depots was larger in males than in females and was a major predictor of mRNA levels of leptin, PAI-1, and adiponectin. Gender, but not adipocyte size, was significantly correlated with pro-inflammatory cytokine expression. BMI and waist circumference were correlated positively with VAT adipocyte size and negatively with SAT adipocyte size. VAT adiponectin and IL-6 expression levels were major predictors of HDL cholesterol concentrations, independent of gender, adiposity, and insulin sensitivity.ConclusionsAdipose tissue morphology and function in obese adolescents are influenced by gender and anatomic location; the pattern of gender- and depot-related differences in adipocyte size and adipokine expression suggests that adolescent males, relative to the females, are at increased risk for obesity-related metabolic co-morbidities.

Impaired HDL function in obese adolescents: Impact of lifestyle intervention and bariatric surgery

HDL regulates endothelial function via stimulation of nitric oxide production. It is documented that endothelial function is impaired in obese adolescents, and improved by lifestyle interventions (LI). HDL function in obese adolescents and the impact of LI or Roux-en-Y gastric bypass surgery (RYGB) was assessed. HDL was isolated from 14 adolescents with normal body mass index (HDLcontrol ), 10 obese (HDLobese ) before and after 6 month LI, and five severe obese adolescents before and one year after RYGB. HDL-mediated phosphorylation of endothelial nitric oxide synthase (eNOS)-Ser(1177) , eNOS-Thr(495) , and PKC-ßII was evaluated. In addition the HDL proteome was analyzed. HDLobese -mediated eNOS-Ser(1177) phosphorylation was reduced, whereas eNOS-Thr(495) phosphorylation increased significantly when compared to HDLcontrol . No impact of obesity was observed on PKC-ßII phosphorylation. LI and RYGB had no impact on HDL-mediated phosphorylation of eNOS and PKC-ßII. A principle component plot analysis of the HDL particle separated controls and severe obese, whereas the interventions did not trigger sufficient differences to the HDL proteome to permit distinction. These results demonstrated that HDL-function is impaired in obese adolescents, and that LI or RYGB did not correct this dysfunction. This might be an argument for developing earlier prevention strategies in obese adolescents to avoid HDL dysfunction.