Risk Factors In Obese Adolescents Research Articles

The Effects of Different Exercise Modalities in the Treatment of Cardiometabolic Risk Factors in Obese Adolescents with Sedentary Behavior—A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Purpose: Obesity has become increasingly prevalent in adolescents due to unhealthy diet habits, sedentary behavior and a lack of physical activities. This study aims to assess the effects of different exercise modalities in the treatment of cardiometabolic risk factors (CRF) in obese adolescents with sedentary behavior. Methods: A systematic search was conducted using databases (PubMed, Embase, Cochrane library, Web of Science, CNKI and VIP database) from the earliest available date to August 2021. Nineteen randomized controlled trials (RCTs) with 704 participants were included. The included studies were evaluated for methodological quality by the Cochrane bias risk assessment tool, and a statistical analysis was performed by the Review Manage 5.3 and Stata 15.1 software. Results: The results of the meta-analysis showed that exercise could significantly improve obese adolescents’ body mass index (BMI) (MD = −1.99, 95% CI: −2.81 to −1.17, p < 0.00001), low density liptein cholesterol (LDL-C) (SMD = −0.98, 95% CI: −1.58 to −0.37, p = 0.002), triglyceride (TG) (SMD = −0.93, 95% CI: −1.72 to −0.14, p = 0.02), total cholesterol (TC) (SMD = −1.00, 95% CI: −1.73 to −0.26, p = 0.008), peak oxygen uptake (VO2peak) (MD = 3.27, 95% CI: 1.52 to 5.02, p = 0.0003) and homeostatic model assessment insulin resistance (HOMA-IR) (SMD = −2.07, 95% CI: −3.3 to −0.84, p = 0.001). However, there was no statistically significant difference in high-density liptein cholesterol (HDL-C) (SMD = 0.40, 95% CI: −0.28 to 1.08, p = 0.25). Conclusion: Exercise can effectively improve cardiometabolic risk factors in obese adolescents with sedentary behavior. For obese adolescents who want to lose weight and improve cardiorespiratory fitness, combined aerobic and resistance training and high-intensity interval training are optimal choices. For obese adolescents with high blood lipids, aerobic training can be regarded as a primary exercise modality to reduce the high risk of cardiovascular diseases; For obese adolescents with insulin resistance, combined aerobic and resistance training can be considered to reduce the high risk of diabetes. It is hoped that more high-quality studies will further expand the meta-analysis results and demonstrate the optimal exercise frequency and treatment intensity of cardiometabolic risk factors in obese adolescents with sedentary behavior in the future.

Identification of Cardiovascular Risk Factors in Obese Adolescents With Metabolic Syndrome.

Objective: There are studies that show different associations between metabolic syndrome (MS) and cardiovascular disease in adolescent. This study is aimed to identify probable cardio-vascular risk factors in obese adolescents with MS.Methods: Sixty-five obese adolescents with a body mass index (BMI) > 95 percentile were enrolled and divided into two groups with MS or without MS. Left ventricular mass (LVM), left ventricular mass index, ejection fraction, epicardial fat thickness, visceral fat thickness (VFT) and carotid intima-media thickness were measured. Anthropometric and blood chemistry parameters were estimated. Above parameters were compared based on presence or absence of MS.Results: The prevalence of MS was 23.1% in obese adolescents. LVM showed significant correlation with body mass index (BMI), hip circumference (HC), fat mass, total cholesterol (TC), LDL-cholesterol (LDL-C) and waist circumference (WC). VFT significantly correlated with WC, BMI, hip circumflex (HC), obesity index (OI), fat %, fat mass, insulin, TC, LDL-C, insulin, triglyceride (TG), glucose, homeostatic model assessment for insulin resistance (HOMA-IR) and leptin.Conclusions: Screening for the MS in overweight adolescents may help to predict risk of future cardiovascular disease. These data suggest that LVMI and VFT are significant parameters for predicting cardiovascular disease risk in obese adolescents.

Associations between Emotional Eating and Metabolic Risk Factors at Adolescents with Obesity

Purpose: This study aimed to determine whether emotional eating (EE) and uncontrolled eating (UCE) scores affect the metabolic risk factors in obese adolescents. Methods: A sample of 100 adolescents have BMI-SDS between 1.41 and 2.83 (aged 12-17 years) was selected. EE and UCE scores were estimated using the TFEQ21. The association of EE and UCE with anthropometric data, lipid profile, glucose profile, liver enzymes, and inflammation factors was assessed in boys and girls. Results: Using Spearman rank correlation, EE scores significantly correlated with uric acid (r = 0.393 and P = 0.001), CRP (r = 0.273 and P = 0.017), TG (r = 0.317 and P = 0.001), TC (r = 0.258 and P = 0.019) and VAI (r = 0.276 and P = 0.034). Also UCE scores were showed positive correlation with CRP (r = 0.257 and P = 0.024). Conclusion: In conclusion, interrelationships tend to exist between EE and triglyceride, uric acid, visceral adiposity index, and CRP levels among obese adolescents.

Is Macronutrients Intake a Challenge for Cardiometabolic Risk in Obese Adolescents?

(1) Background: Pediatric obesity is an emerging public health issue, mainly related to western diet. A cross-sectional study was conducted to explore the association between macronutrients intake and cardiometabolic risk factors in obese adolescents. (2) Methods: Ninety-three Italian obese adolescents were recruited; anthropometric parameters, body composition, glucose and lipid metabolism profiles were measured. Macronutrients intake was estimated by a software-assisted analysis of a 120-item frequency questionnaire. The association between macronutrients and cardiometabolic risk factors was assessed by bivariate correlation, and multiple regression analysis was used to adjust for confounders such as age and sex. (3) Results: By multiple regression analysis, we found that higher energy and lower carbohydrate intakes predicted higher body mass index (BMI) z-score, p = 0.005, and higher saturated fats intake and higher age predicted higher HOmeostasis Model Assessment of insulin resistance (HOMA-IR) and lower QUantitative Insulin-sensitivity ChecK (QUICK) index, p = 0.001. In addition, a saturated fats intake <7% was associated with normal HOMA-IR, and a higher total fats intake predicted a higher HOMA of percent β-cell function (HOMA-β), p = 0.011. (4) Conclusions: Higher energy intake and lower carbohydrate dietary intake predicted higher BMI z-score after adjustment for age and sex. Higher total and saturated fats dietary intakes predicted insulin resistance, even after adjustment for confounding factors. A dietary pattern including appropriate high-quality carbohydrate and reduced saturated fat intakes could result in reduced cardiometabolic risk in obese adolescents.

Anatomical risk factors in obese adolescents with obstructive sleep apnea

Anatomical risk factors in obese adolescents with obstructive sleep apnea

Thyroid Function in Obese Children with Non-Alcoholic Fatty Liver Disease

Ob­jec­ti­ve: To investigate the relationships between thyroid function and metabolic risk factors in obese adolescents with non-alcoholic fatty liver disease (NAFLD).Methods: One hundred sixty obese adolescents and 40 control subjects were enrolled in the study. The obese subjects were divided into two groups based on presence or absence of liver steatosis (NAFLD group and non-NAFLD group). Serum samples were assayed for glucose, insulin, cholesterol, alanine aminotransferase, aspartate aminotransferase, free thyroxine (fT4), free triiodothyronine (fT3) and thyroid-stimulating hormone (TSH). The ratio of fT3 to fT4 was evaluated as an indirect index of deiodinase activity. Insulin resistance was evaluated by homeostasis model assessment (HOMA-IR) from fasting samples.Results: NAFLD and non-NAFLD groups had slightly higher fasting blood glucose values than the control group. Fasting insulin levels in the NAFLD group were significantly higher than those in the non-NAFLD and control groups. The NAFLD group had significantly greater HOMA-IR values compared with the non-NAFLD group and also with the control group. The NAFLD group had significantly higher fT3/fT4 ratio values compared to both non-NAFLD and control groups. fT3/fT4 was positively correlated with serum insulin levels in the NAFLD group. Conclusion: This study showed that obese adolescents with hepatosteatosis had elevated values for fT3/fT4 ratio. This finding suggested a high conversion of T4 to T3 due to increased deiodinase activity as a compensatory mechanism for fat accumulation.

Recreational Soccer to Prevent Cardiovascular Risk Factors in Obese Adolescents

Recreational Soccer to Prevent Cardiovascular Risk Factors in Obese Adolescents

Improvements on Cardiovascular Diseases Risk Factors in Obese Adolescents: A Randomized Exercise Intervention Study.

It is unclear how different exercise intensities affect cardiovascular disease (CVD) risk factors in obese adolescents. The aim of this study was to compare the effects of high-intensity (HIT) vs. low-intensity (LIT) aerobic training on CVD risk factors in obese adolescents. Forty-three obese adolescents (age: 15.7 ± 1.3 years, BMI: 34.3 ± 4.1 kg/m(2)) participated this study either HIT (corresponding to ventilatory threshold I; N = 20) or LIT (20% below ventilatory threshold I; N = 23) for 12 weeks. All sessions were isocaloric (350 kcal). All participants received the same nutritional, psychological, and clinical counseling. Subjects were assessed in fatness, fitness, lipid profile, and glucose at baseline and after 12 weeks. The CVD risk factors assessed were waist circumference (WC), total cholesterol (TC), high-density lipoprotein (HDL), glucose, and fitness, which were single and clustered analyzed (z scores sum). Body mass, Body Mass Index, fatness, and WC were improved (P < .001) in both groups. The sum of z scores (WC + TC + glucose-fitness-HDL) improved in both HIT (12 weeks = -2.16 SD; Cohen's d = .45) and LIT (12 weeks = -2.13 SD; Cohen's d = .60) without groups differences. Changes in fitness were associated with changes in WC (r = -.48; P = .003). HIT does not promote any additional improvements in CVD risk factors than LIT in obese adolescents.

Measurement site influences abdominal subcutaneous and visceral adipose tissue in obese adolescents before and after exercise.

The objective of this study was to determine if abdominal adipose tissue (AT) measurement site influences the association between baseline and change in abdominal subcutaneous (ASAT) and visceral AT (VAT), and metabolic risk factors in obese adolescents. Fifty-five obese adolescents (14.9 ± 1.7 years; 51% male; 42% white) participated in an aerobic or resistance exercise intervention three times/week for 3 months. We compared the association between changes in abdominal AT area (spanning 5 cm below to 15 cm above L4-L5) and volume measured by magnetic resonance imaging with concomitant changes in metabolic risk. All AT areas were significantly (p < 0.05) correlated with the respective volume at baseline and follow-up. Baseline VAT areas at 5 and 10 cm above L4-L5 were more strongly associated with VAT volume than VAT area at L4-L5 (p < 0.05). After the intervention, changes in the area at 5 and 10 cm above L4-L5 were more strongly associated with changes in AT volumes than changes in L4-L5 (p < 0.05). Changes in abdominal AT volumes were more strongly associated with insulin area under the curve than any single-slice abdominal AT area. The measurement site for abdominal AT has significant influence on the relationships with total VAT or ASAT and metabolic risk factors in obese adolescents before and after an exercise intervention.

Abstract P429: Parallel Processes of Sedentary Behavior and Cardiometabolic Risk Factors in Obese Adolescents

Introduction: Sedentary time has been negatively associated with cardiometabolic health in adults. These associations are less clear in youth, may differ by sedentary measurement method, and rarely have been investigated longitudinally. Hypothesis: Greater accelerometer measured sedentary time and reported screen time will be associated with poorer status on cardiometabolic risk factors at baseline and longitudinally. Methods: Obese (BMI ≥ 95th percentile for age and gender) 11-13 year olds were enrolled in a primary care weight loss trial. Half were girls and 82% were Hispanic. Of the 106 participants enrolled, 73 completed baseline and 12-month assessments. Assessments occurred in the clinic and included a fasting blood draw. Table 1 lists the risk factor variables. The first dependent variable was reported screen time (television and computer/video games). The second was total sedentary time, calculated from waist-worn Actigraph accelerometers as percent of wear time with counts &lt; 100 per 60-second epoch. Mplus software was used to fit latent growth parallel processes models, with the intercept of the biomarker regressed on the sedentary time intercept (cross-sectional association), and the slope of the biomarker regressed on the sedentary time slope (longitudinal association). Models were adjusted for potential confounders. Full information maximum likelihood estimation was used to account for missing data. Results: Participants reported 3.2 (SD = 2.0) screen time hours. Associations between screen time and risk factors are presented in Table 1. Total sedentary time (M = 61±11% of wear time) was positively associated with BMI (β = .22; p &lt; .05) at baseline but not with other risk factors. Total sedentary time was not associated with risk factors longitudinally. Conclusion: Changes in screen time but not total sedentary time were associated with cardiometabolic risk factors, specifically BMI, blood glucose, LDL, AST, and ALT. Associations were independent of physical activity and psychosocial diet variables.

Association of nonalcoholic fatty liver disease with cardiovascular risk factors in obese adolescents: the role of interdisciplinary therapy.

Obesity is associated with several cardiovascular risk factors, including nonalcoholic fatty liver disease (NAFLD). These risk factors can induce changes in the arteries such as an increase in the carotid intima-media thickness (cIMT), which contributes to the early development of atherosclerosis. To determine whether NAFLD is associated with an atherogenic lipid profile, inflammatory markers, or cIMT in obese adolescents and to compare the effects of therapeutic lifestyle changes in NAFLD and non-NAFLD groups. A total of 79 obese adolescents were divided into two groups: 33 NAFLD and 46 non-NAFLD. They were submitted to an interdisciplinary therapy involving diet exercise and psychological support during the course of 1 year. The cIMT and estimates of fat mass (liver, intra-abdominal, and subcutaneous) were determined ultrasonographically. Body composition, glucose, lipid profile, and adipokines were analyzed before and after the therapy. At baseline, only in the NAFLD group was the homeostasis model assessment of insulin resistance positively correlated with cIMT and triglyceride/high-density lipoprotein cholesterol ratio. Therapy was associated with an increase in adiponectin concentrations and reduced visceral fat, cIMT, leptin, and plasminogen activator inhibitor-1 concentrations, as well as the ratios of total cholesterol/high-density lipoprotein cholesterol and triglycerides/high-density lipoprotein cholesterol in both groups. Only in the non-NAFLD group did therapy result in a reduction in the low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio and increased high-density lipoprotein cholesterol concentration. In obese adolescents, NAFLD is associated with cardiovascular risk factors and inflammatory markers of atherosclerosis that were positively correlated with cIMT only in the NAFLD group. Nevertheless, the strength of the present study is that the interdisciplinary therapy effectively improved cIMT and other proinflammatory adipokines in both groups.

Preperitoneal Fat Tissue May Be Associated with Arterial Stiffness in Obese Adolescents

Vascular aging is a chronic process, and many negative effects of obesity in this process have been well defined. We assessed arterial stiffness in obese adolescents and evaluated the relationship between intra-abdominal fat distribution and arterial stiffness. Arterial stiffness parameters and pulse wave velocity (PWV) were evaluated in 61 obese adolescents and 58 healthy controls. Carotid-femoral PWV was calculated by arterial tonometry. Additionally, all obese children were evaluated for metabolic syndrome and insulin resistance. Intra-abdominal fat distribution, including subcutaneous, preperitoneal and visceral fat thicknesses, was assessed by ultrasonography. PWVs of obese children were significantly higher than those of healthy controls (5.0 ± 0.7 m/s vs. 4.7 ± 0.5 m/s). Parameters affecting PWV were evaluated by regression analysis. The independent variable in the regression analysis model was PWV, and the dependent variables were age, metabolic syndrome, body mass index and Homeostasis Model Assessment—Insulin Resistance, as well as subcutaneous, preperitoneal and visceral fat tissue thicknesses measured by ultrasonography. The only parameter associated with PWV was preperitoneal fat tissue thickness. Vascular changes related to obesity may begin in adolescence, as illustrated by the increased PWV. Preperitoneal fat tissue may be related to arterial stiffness. Intra-abdominal fat distributions obtained by ultrasonography may provide clinicians with valuable information needed to determine cardiovascular disease risk factors in obese adolescents.

A Review of Randomized Controlled Trials of Aerobic Exercise Training on Fitness and Cardiometabolic Risk Factors in Obese Adolescents

Aerobic training is the most prescribed exercise modality for the management of pediatric obesity. There is strong evidence that it decreases waist circumference, percent body fat and visceral fat, increases cardiorespiratory fitness, and decreases blood pressure in obese adolescents. However, the independent effects of aerobic exercise training on other cardiometabolic risk factors (ie, insulin resistance markers, plasma lipid levels, and inflammatory markers) are limited and yield inconsistent findings. Our article reviews randomized controlled trials evaluating the effects of aerobic exercise training on body composition, fitness, lipid levels, and insulin resistance in obese adolescents (aged 13-18 years) and outlines future research directions for this population.

Association Between Insulin Resistance and Oxidative Stress Parameters in Obese Adolescents with Non-Alcoholic Fatty Liver Disease

Objective: Non-alcoholic fatty liver disease (NAFLD) has become one of the most common chronic liver diseases in children. The aim of this study was to investigate the associations of oxidative stress with insulin resistance and metabolic risk factors in obese adolescents with NAFLD.Methods: Forty-six obese adolescents (23 girls and 23 boys, mean age: 12.8±2.2 years) and 29 control subjects (15 girls and 14 boys, mean age: 12.7±2.7 years) were enrolled in the study. The obese subjects were divided into two groups (NAFLD group and non-NAFLD group) based on the elevated alanine aminotransferase levels (>30 IU/L) and the presence or absence of liver steatosis detected by ultrasonography. Insulin resistance was evaluated by homeostasis model assessment (HOMA-IR) from fasting samples. Plasma total antioxidant status (TAS) and total oxidant status (TOS) level measurements (REL Assay Diagnostics) were done in all participants. The ratio of TOS to TAS was regarded as an oxidative stress index (OSI), an indicator of the degree of OS.Results: Fasting insulin levels and HOMA-IR values in the NAFLD group were significantly higher than in the non-NAFLD and control groups. TAS measurements were decreased in both obese groups (NAFLD and non-NAFLD) in comparison with the control group. TOS and OSI measurements were higher in the NAFLD group than in the non-NAFLD and control groups. OSI was positively correlated with fasting insulin (r=0.67, p=0.01) and HOMA-IR (r=0.71, p=0.02) in the NAFLD obese group.Conclusions: In this cross-sectional study, elevated OS markers in obese adolescents with NAFLD were associated with insulin resistance. This data suggest that an antioxidant therapy might have a potential for treating NAFLD associated with insulin resistance.Conflict of interest:None declared.

Assess The Effect of Resistance Training Compared To a Weight Loss Diet Program, on Body Composition, Insulin Sensitivity and Cardio-Vascular Risk Factors In Obese Adolescents.

Purpose: To evaluate the effect of a Resistance training program (BT) versus weight loss diet (DR) on body composition, insulin sensitivity and cardiovascular risk factors in obese adolescents. Methods: Thirty obese adolescents with a BMI above the 97th percentile participated in a training program and diet for 12 weeks. They were randomized into two groups: a diet group (DR, n = 16) with a caloric restriction of 500 kcal / day and Strength training group (BT, n = 14) for all major muscle groups, three sessions / week with an intensity of 50-80% (1.RM) for 3 months. Anthropometric and biochemical measurements were performed for all of our subjects before and after the intervention program of 12 weeks. Results: Significant variations of body composition parameters were observed in both groups. The decrease of BMI, body weight, fat mass and (WC) for the group (DR) was more important than the group (BT) (p <0.01 and p <0.05 respectively). Strength training significantly increases the sensitivity to insulin (HOMA-IR of group (BT), was 4.53 ± 1.2 before and 3.47 ± 1.4 after the training program (p <0.05)), while there was no significant change for the group (DR). 12 weeks of strength training, improves the plasma concentrations of TG and HDL-C the LDL-C/HDL-C reports, TC / HDL-C and HDL-C / TG (p <0.05). The diet of weight loss induced a significant decrease only for the TC and LDL-C. (4,46 ± 0.24 before to 4.15 ± 0.37 after and 2.68 ± 0.18 before to 2.42 ± 0.14 after (p <0.05) respectively). Conclusion: Strength training improves much more the sensitivity to insulin and cardiovascular risk factors than weight loss diet program. The latter is more effective for weight loss, BMI and body fat in obese adolescent boys.

Correlation of insulin sensitivity with bone mineral status in obese adolescents with nonalcoholic fatty liver disease

The aim of this study was to investigate the relationships between bone mineral density (BMD) vs insulin resistance and metabolic risk factors in obese adolescents with nonalcoholic fatty liver disease (NAFLD). Eighty-two obese adolescents [45 girls and 37 boys, mean age: 12·3 ± 1·7 years, mean body mass index-standard deviation score (BMI-SDS): 1·9 ± 0·2] and 30 control subjects (15 girls and 15 boys, mean age: 12·3 ± 1·45 years, mean BMI-SDS: 0·5 ± 0·7) were enrolled the study. The obese subjects were divided into two groups based on the presence or absence of liver steatosis with high transaminases (NAFLD group and non-NAFLD group). Insulin resistance was evaluated by homeostasis model assessment (HOMA-IR) from fasting samples. BMD was determined by dual-energy X-ray absorptiometry. Fasting insulin levels in the NAFLD group were significantly higher than in the non-NAFLD obese (32·3 ± 24·0 vs 11·02 ± 2·95 mU/l, P < 0·001) and control groups (8·4 ± 2·4 mU/l, P< 0·001). The NAFLD group had higher values of HOMA-IR than the non-NAFLD obese (7·3 ± 0·1 vs 2·3 ± 0·7, P < 0·001) and control groups (1·8 ± 0·5, P < 0·001). BMD-SDS measurements were lower in the NAFLD group than in the non-NAFLD (0·56 ± 0·3 vs 1·02 ± 0·9, P < 0·001) and control groups (0·56 ± 0·3 vs 1·37 ± 1·04, P < 0·001). BMD-SDS was positively correlated with BMI-SDS (r = 0·530, P = 0·004) and negatively correlated with HOMA-IR (r = -0·628, P = 0·017) in the NAFLD obese group. This study reports the association between BMD-SDS and insulin resistance in obese adolescents both with and without NAFLD, although the NAFLD group had a lower BMD-SDS than the non-NAFLD group. We suggest that NAFLD has a detrimental effect on bone health in adolescents, and it is correlated with increased insulin resistance.

Hyperthyrotropinemia in relation to endothelial dysfunction in obese adolescents

It has been shown that isolated elevation of thyroid stimulating hormone (hyperthyrotropinemia) is quite frequent in obese adolescents, but it is not clear whether this condition entails an increased risk related to body mass index (BMI). The aim of the current study was to investigate the relationship between hyperthyrotropinemia and endothelial dysfunction and other cardiovascular risk factors in obese adolescents. Seventeen obese adolescents with hyperthyrotropinemia (TSH ≥ 4.2 μUI/ml) (group 1), 21 obese adolescents with normal thyroid stimulating hormone (TSH) level (group 2) and 10 age- and sex-matched healthy lean controls were included in the study. Fasting blood glucose (FBG), lipid profile, insulin resistance (HOMA-IR) and thyroid hormones were determined. All participants were subjected to ultrasound recording of brachial artery diameter at rest and after reactive hyperemia (FMD) for assessment of endothelial function. BMI and free triiodothyronine (fT3) levels were higher in obese adolescents with hyperthyrotropinemia (group 1) than in those with normal TSH (group 2) (p < 0.05), but there were no significant differences between the two groups in other metabolic parameters (lipid profile and HOMA-IR). The FMD was significantly low in obese adolescents (groups 1 and 2) relative to controls (3.4 ± 18% in group 1 and 3.6 ± 2.2% in group 2 vs. 10.4 ± 3.1% in control subjects), but there was no statistical difference between obese adolescents with hyperthyrotropinemia (group 1) and those with normal TSH (group 2). There were positive correlations between TSH and BMI (p = 0.03) and between fT3 and BMI (p = 0.04), but no correlation between TSH and lipid profile, HOMA-IR or FMD. Hyperthyrotropinemia is not related to endothelial dysfunction or metabolic risk factors in obese adolescents.

Sleep-disordered breathing in obese adolescents is associated with visceral adiposity and markers of insulin resistance

Sleep-disordered breathing is associated with obesity, insulin resistance, and the metabolic syndrome in adults. Similar data in children is limited and conflicting. This pilot study examined the relationships between sleep-disordered breathing, visceral adiposity, and cardiometabolic risk factors in obese adolescents. Twenty obese (body mass index ≥ 95(th) percentile), otherwise healthy adolescents (age 14.9 ± 2 years) underwent polysomnogram studies, fasting lipid profile and oral glucose tolerance tests, and measures of body composition (dual-energy X-ray absorptiometry) and visceral adiposity (abdominal computed tomography). The severity of sleep-disordered breathing (as measured by apnea-hypopnea index) was positively associated with visceral adipose tissue (r = 0.73, p < 0.001) but not with other measures of body composition. After controlling for body mass index, the severity of sleep-disordered breathing was positively associated with markers of insulin resistance (homeostasis model assessment and fasting insulin). Further study to allow for critical assessment of the relationships between sleep-disordered breathing and cardiometabolic risk factors in obese youth remains necessary.

Treatment of Obese Adolescents: The Influence of Periodization Models and ACE Genotype

The aims of the present study were to compare the effects of two periodization models on metabolic syndrome risk factors in obese adolescents and verify whether the angiotensin-converting enzyme (ACE) genotype is important in establishing these effects. A total of 32 postpuberty obese adolescents were submitted to aerobic training (AT) and resistance training (RT) for 14 weeks. The subjects were divided into linear periodization (LP, n = 16) or daily undulating periodization (DUP, n = 16). Body composition, visceral and subcutaneous fat, glycemia, insulinemia, homeostasis model assessment of insulin resistance (HOMA-IR), lipid profiles, blood pressure, maximal oxygen consumption (VO(2max)), resting metabolic rate (RMR), muscular endurance were analyzed at baseline and after intervention. Both groups demonstrated a significant reduction in body mass, BMI, body fat, visceral and subcutaneous fat, total and low-density lipoprotein cholesterol, blood pressure and an increase in fat-free mass, VO(2max), and muscular endurance. However, only DUP promoted a reduction in insulin concentrations and HOMA-IR. It is important to emphasize that there was no statics difference between LP and DUP groups; however, it appears that there may be bigger changes in the DUP than LP group in some of the metabolic syndrome risk factors in obese adolescents with regard to the effect size (ES). Both periodization models presented a large effect on muscular endurance. Despite the limitation of sample size, our results suggested that the ACE genotype may influence the functional and metabolic characteristics of obese adolescents and may be considered in the future strategies for massive obesity control.

Efficacy of weight loss drugs on obesity and cardiovascular risk factors in obese adolescents: a meta‐analysis of randomized controlled trials

Weight loss drugs have been developed to reduce the comorbidities associated with excess weight. We conducted a meta-analysis of the efficacy of orlistat and sibutramine on weight, body mass index, waist circumference and cardiovascular risk factors in overweight adolescents. MEDLINE and the Cochrane Library were searched for relevant articles using MESH terms and keywords. Studies were included if they had reported quantitative estimates and standard deviations of the association between each weight loss drug and weight, with information on at least one cardiovascular risk factor. A total of eight trials (three orlistat and five sibutramine) with information on 1391 individuals was included in the present analysis. The mean decrease in weight between the intervention and control groups was 5.25 kg (95% confidence interval: 3.03-7.48) after a minimum follow-up of 6 months. There was evidence of statistical heterogeneity between the studies (I(2) = 76%) that was no longer apparent after exclusion of trials of orlistat (mean weight decrease = 5.32 kg; I(2) = 38%). There was little evidence that treatment was associated with adverse effects on cardiovascular risk factors but this requires verification from future large trials with longer study follow-up.