OBJECTIVE: To evaluate the correlation between neck circumference and insulin resistance and components of metabolic syndrome in adolescents with different adiposity levels and pubertal stages, as well as to determine the usefulness of neck circumference to predict insulin resistance in adolescents. METHODS:Cross-sectional study with 388 adolescents of both genders from ten to 19 years old. The adolescents underwent anthropometric and body composition assessment, including neck and waist circumferences, and biochemical evaluation. The pubertal stage was obtained by self-assessment, and the blood pressure, by auscultation. Insulin resistance was evaluated by the Homeostasis Model Assessment-Insulin Resistance. The correlation between two variables was evaluated by partial correlation coefficient adjusted for the percentage of body fat and pubertal stage. The performance of neck circumference to identify insulin resistance was tested by Receiver Operating Characteristic Curve. RESULTS: After the adjustment for percentage body fat and pubertal stage, neck circumference correlated with waist circumference, blood pressure, triglycerides and markers of insulin resistance in both genders. CONCLUSIONS: The results showed that the neck circumference is a useful tool for the detection of insulin resistance and changes in the indicators of metabolic syndrome in adolescents. The easiness of application and low cost of this measure may allow its use in Public Health services.

Objective: To verify the prevalence of metabolic syndrome and insulin resistance in obese adolescents and its relationship with different body composition indicators. Methods: A cross-sectional study comprising 79 adolescents aged ten to 18 years old. The assessed body composition indicators were: body mass index (BMI), body fat percentage, abdominal circumference, and subcutaneous fat. The metabolic syndrome was diagnosed according to the criteria proposed by Cook et al. The insulin resistance was determined by the Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) index for values above 3.16. The analysis of ROC curves was used to assess the BMI and the abdominal circumference, aiming to identify the subjects with metabolic syndrome and insulin resistance. The cutoff point corresponded to the percentage above the reference value used to diagnose obesity. Results: The metabolic syndrome was diagnosed in 45.5% of the patients and insulin resistance, in 29.1%. Insulin resistance showed association with HDL-cholesterol (p=0.032) and with metabolic syndrome (p=0.006). All body composition indicators were correlated with insulin resistance (p<0.01). In relation to the cutoff point evaluation, the values of 23.5 and 36.3% above the BMI reference point allowed the identification of insulin resistance and metabolic syndrome. The best cutoff point for abdominal circumference to identify insulin resistance was 40%. Conclusions: All body composition indicators, HDL-cholesterol and metabolic syndrome showed correlation with insulin resistance. The BMI was the most effective anthropometric indicator to identify insulin resistance.

Summary Objective In adults, hypothalamic gliosis has been documented using quantitative T2 neuroimaging, whereas functional magnetic resonance imaging (fMRI) has shown a defective hypothalamic response to nutrients. No studies have yet evaluated these hypothalamic abnormalities in children with obesity. Methods Children with obesity and lean controls underwent quantitative MRI measuring T2 relaxation time, along with continuous hypothalamic fMRI acquisition to evaluate early response to glucose ingestion. Results Children with obesity (N = 11) had longer T2 relaxation times, consistent with gliosis, in the mediobasal hypothalamus (MBH) compared to controls (N = 9; P = 0.004). Moreover, there was a highly significant group*region interaction (P = 0.002), demonstrating that signs of gliosis were specific to MBH and not to reference regions. Longer T2 relaxation times correlated with measures of higher adiposity, including visceral fat percentage (P = 0.01). Mean glucose‐induced hypothalamic blood oxygen‐level dependent signal change did not differ between groups (P = 0.11). However, mean left MBH T2 relaxation time negatively correlated with glucose‐induced hypothalamic signal change (P < 0.05). Conclusion Imaging signs of hypothalamic gliosis were present in children with obesity and positively associated with more severe adiposity. Children with the strongest evidence for gliosis showed the least activation after glucose ingestion. These initial findings suggest that the hypothalamus is both structurally and functionally affected in childhood obesity.

Although this study does not reflect reality, it can be used as a warning to pediatricians.

BackgroundThere is no consensus regarding obesity repercussions for lung function in children and adolescents. Therefore, the aim of the study was to determine whether obesity is associated with poor physical conditioning and damaged lung function in children and adolescents, and to correlate lung function with six-minute walk test (6MWT) results.MethodsThis cross-sectional study included 38 obese subjects of both sexes, ranging between 5 and 17 years of age, as well as 56 control subjects paired by sex and age for the 6MWT, and 39 subjects for spirometry. Subjects performed spirometry according to the guidelines of the American Thoracic Society (ATS) and the European Respiratory Society. The obese group repeated spirometry after receiving bronchodilator (BD) treatments. Physical performance was evaluated via the 6MWT according to ATS guidelines.ResultsThe obese group demonstrated lower forced expiratory volumes in the first second compared with the control group based on forced vital capacity indices (p < 0.01), findings consistent with airway obstruction in 36.8% of patients in the obese group. Walking distances were shorter in the obese group than in the control group. Changes in lung function did not correlate directly with performance on the 6MWT among obese patients. However, there was a correlation between lung function and variables indicative of effort during exercise.ConclusionIn the present study, the obese group walked shorter distances and demonstrated lower values in some markers of lung function. However, there is no relationship between their physical conditions and these test results. Therefore, we cannot conclusively state that poor physical performance results from damaged pulmonary function.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2466-14-199) contains supplementary material, which is available to authorized users.

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; for the Brazilian Metabolic Syndrome Study (BRAMS) Investigators IMPORTANCE The association between short sleep duration and decreased insulin sensitivity in adolescents has been described. However, to our knowledge, no studies have investigated this association measuring insulin sensitivity by the hyperglycemic clamp technique. OBJECTIVES To compare the distributions of parameters of insulin resistance in adolescents with sleep deprivation vs adequate sleep, and to investigate the association between sleep deprivation and insulin sensitivity. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional multicenter study using data from the Brazilian Metabolic Syndrome Study conducted from June 29, 2011, to December 3, 2014, at an obesity outpatient clinic at the University of Campinas and public schools, with a convenience sample of 615 adolescents aged 10 to 19.9 years with a body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) for age and sex at the fifth percentile or higher. A subsample of 81 adolescents underwent the hyperglycemic clamp technique. MAIN OUTCOMES AND MEASURES The self-reported sleep duration was used to classify the population into 2 groups: adolescents with sleep deprivation (<8 hours/night) and adolescents with adequate sleep (Ն8 hours/night). Insulin sensitivity was assessed using the hyperglycemic clamp technique. RESULTS Among the 615 adolescents (56.3% female; median age, 15.9 years [interquartile range, 12.9-17.8 years]) included in the sample, the mean (SD) sleep duration was 7.9 (1.7) hours/night. The adolescents with sleep deprivation (n = 257) compared with those with adequate sleep (n = 358) had a higher median (interquartile range) age (17.

OBJECTIVE To analyze the reasons for non-adherence to follow-up at a specialized outpatient clinic for obese children and adolescents. METHODS Descriptive study of 41 patients, including information from medical records and phone recorded questionnaires which included two open questions and eight closed ones: reason for abandonment, financial and structural difficulties (distance and transport costs), relationship with professionals, obesity evolution, treatment continuity, knowledge of difficulties and obesity complications. RESULTS Among the interviewees, 29.3% reported that adherence to the program spent too much time and it was difficult to adjust consultations to patientsâ€(tm) and parentsâ€(tm) schedules. Other reasons were: childrenâ€(tm)s refusal to follow treatment (29.3%), dissatisfaction with the result (17.0%), treatment in another health service (12.2%), difficulty in schedule return (7.3%) and delay in attendance (4.9%). All denied any relationship problems with professionals. Among the respondents, 85.4% said they are still overweight. They reported hurdles to appropriate nutrition and physical activity (financial difficulty, lack of parentsâ€(tm) time, physical limitation and insecure neighborhood). Among the 33 respondents that reported difficulties with obesity, 78.8% had emotional disorders such as bullying, anxiety and irritability; 24.2% presented fatigue, 15.1% had difficulty in dressing up and 15.1% referred pain. The knowledge of the following complications prevailed: cardicac (97.6%), aesthetic (90.2%), psychological (90.2%), presence of obesity in adulthood (90.2%), diabetes (85.4%) and cancer (31.4%). CONCLUSIONS According to the results, it is possible to create weight control public programs that are easier to access, encouraging appropriate nutrition and physical activities in order to achieve obesity prevention.