Cut-off values of waist circumference to predict metabolic syndrome in obese adolescents / Los valores de corte de circunferencia de cintura para predecir el síndrome metabólico en adolescentes obesos

Introduction: Metabolic syndrome (MetS) is a constellation of metabolic alterations related to abdominal obesity, inflammation and insulin resistance, which increase cardiovascular disease and mortality. The aims of the present study were to identify the prevalence of comorbidities and altered parameters in obese adolescents with and without MetS, and determine cut-off points of waist circumference to predict MetS. Methods: 195 obese adolescents were recruited and divided according to MetS diagnosis based on IDF criteria. Blood analyses of glucose, lipids, liver enzymes, adiponectin and leptin were measured. Insulin resistance was assessed by HOMA-IR, QUICKI and HOMA-AD. Visceral, subcutaneous and hepatic fat were ultrasonography obtained. Body composition was estimated by BOD POD system. Results: We observed a prevalence of 25% of MetS (n=50). The MetS group presented significantly higher body mass, BMI, body fat (kg), free-fat mass (kg), waist circumference, visceral fat, glucose, insulin, insulin resistance, total-cholesterol, LDL-c, VLDL-c, triglycerides, liver enzymes, blood pressure and non-alcoholic fatty liver disease (NAFLD). Significant lower QUICKI and adiponectin were noted in MetS group. MetS girls presented significantly higher leptin/adiponectin ratio compared to Non-MetS girls. Cut-off points of 111.5 cm for boys and 104.6 cm for girls of waist circumference were suggested to predict metabolic syndrome. Moreover, waist circumference was positively correlated with visceral fat and the number of metabolic syndrome parameters Conclusion: MetS group presented significantly higher metabolic alterations and inflammation compared to Non-MetS group. Waist circumference is considered an anthropometric measure predictor of metabolic syndrome in obese adolescents, being useful in clinical practice (AU)

Introducción: El síndrome metabólico es una constelación de alteraciones metabólicas relacionadas con la obesidad abdominal, la inflamación y la resistencia a la insulina, lo que aumenta las enfermedades cardiovasculares y la mortalidad. Los objetivos del presente estudio fueron determinar la prevalencia de comorbilidades y parámetros alterados en adolescentes obesos con y sin SM, y determinar los puntos de corte de la circunferencia de cintura para predecir SM. Métodos: 195 adolescentes obesos y se los dividió según síndrome metabólico diagnóstico basado en criterios de la IDF. Los análisis de sangre se midieron de glucosa, lípidos, enzimas hepáticas, la adiponectina y leptina. Resistencia a la insulina se evaluó mediante HOMA-IR, QUICKI y HOMA-AD. Se obtuvieron ecografía visceral, subcutánea y grasa hepática. La composición corporal se calcula por el sistema BOD POD. Resultados: Se observó una prevalencia del 25% de síndrome metabólico Mets (n = 50). El grupo grupo con síndrome metabólico presentó mayor masa corporal, índice de masa corporal, grasa corporal (kg), sin grasa masa significativa (kg), circunferencia de la cintura, la grasa visceral, la glucosa, la insulina, resistencia a la insulina, colesterol total, LDL-c, VLDL-c, triglicéridos, enzimas hepáticas, enfermedad no alcohólica del hígado graso (EHNA) y la presión arterial. Se observaron QUICKI significativamente menor y la adiponectina en el grupo con síndrome metabólico. El grupo con síndrome metabólico presentaron significativa proporción de leptina / adiponectina mayor en comparación con los que no tienen síndrome metabólico. Puntos de corte de 111,5 cm para los niños y 104,6 cm para las niñas de la circunferencia de cintura se sugirieron para predecir el síndrome metabólico. Además, la circunferencia de la cintura fue positivamente correlacionada con la grasa visceral y el número de parámetros del síndrome metabólico. Conclusión: El grupo con síndrome metabólico presentan alteraciones metabólicas significativas superiores e inflamación en comparación con el grupo sin síndrome metabólico. La circunferencia de cintura se considera un predictor medida antropométrica del síndrome metabólico en adolescentes obesos, siendo útil en la práctica clínica (AU)

Cut-off values of waist circumference to predict metabolic syndrome in obese adolescents.

INTRODUCTION: Metabolic syndrome (MetS) is a constellation of metabolic alteration related to abdominal obesity, inflammation and insulin resistance, which increase cardiovascular disease and mortality. The aims of the present study were to identify the prevalence of comorbidities and altered parameters in obese adolescents with and without MetS, and determine cut-off points of waist circumference to predict MetS. METHODS: 195 obese adolescents were recruited and divided according to MetS diagnosis based on IDF criteria. Blood analyses of glucose, lipids, liver enzymes, adiponectin and leptin were measured. Insulin resistance was assessed by HOMA-IR, QUICKI and HOMA-AD. Visceral, subcutaneous and hepatic fat were ultrasonography obtained. Body composition was estimated by BOD POD system. RESULTS: We observed a prevalence of 25% of MetS (n=50). The MetS group presented significant higher body mass, BMI, body fat (kg), free-fat mass (kg), waist circumference, visceral fat, glucose, insulin, insulin resistance, total-cholesterol, LDL-c, VLDL-c, triglycerides, liver enzymes, non-alcoholic fatty liver disease (NAFLD) and blood pressure. Significant lower QUICKI and adiponectin in MetS group were noted. MetS girls presented significant higher leptin/adiponectin ratio compared to Non-MetS girls. Cut-off points of 111.5 cm for boys and 104.6 cm for girls of waist circumference were suggested to predict metabolic syndrome. Moreover, waist circumference was positive correlated with visceral fat and the number of metabolic syndrome parameters. CONCLUSION: MetS group presented significant higher metabolic alterations and inflammation compared to Non-MetS group. Waist circumference is considered an anthropometric measure predictor of metabolic syndrome in obese adolescents, being useful in clinical practice.

Introducción: El síndrome metabólico es una constelación de alteraciones metabólicas relacionadas con la obesidad abdominal, la inflamación y la resistencia a la insulina, lo que aumenta las enfermedades cardiovasculares y la mortalidad. Los objetivos del presente estudio fueron determinar la prevalencia de comorbilidades y parámetros alterados en adolescentes obesos con y sin SM, y determinar los puntos de corte de la circunferencia de cintura para predecir SM. Métodos: 195 adolescentes obesos y se los dividió según síndrome metabólico diagnóstico basado en criterios de la IDF. Los análisis de sangre se midieron de glucosa, lípidos, enzimas hepáticas, la adiponectina y leptina. Resistencia a la insulina se evaluó mediante HOMA-IR, QUICKI y HOMA-AD. Se obtuvieron ecografía visceral, subcutánea y grasa hepática. La composición corporal se calcula por el sistema BOD POD. Resultados: Se observó una prevalencia del 25% de síndrome metabólico Mets (n = 50). El grupo grupo con síndrome metabólico presentó mayor masa corporal, índice de masa corporal, grasa corporal (kg), sin grasa masa significativa (kg), circunferencia de la cintura, la grasa visceral, la glucosa, la insulina, resistencia a la insulina, colesterol total, LDL-c, VLDL-c, triglicéridos, enzimas hepáticas, enfermedad no alcohólica del hígado graso (EHNA) y la presión arterial. Se observaron QUICKI significativamente menor y la adiponectina en el grupo con síndrome metabólico. El grupo con síndrome metabólico presentaron significativa proporción de leptina / adiponectina mayor en comparación con los que no tienen síndrome metabólico. Puntos de corte de 111,5 cm para los niños y 104,6 cm para las niñas de la circunferencia de cintura se sugirieron para predecir el síndrome metabólico. Además, la circunferencia de la cintura fue positivamente correlacionada con la grasa visceral y el número de parámetros del síndrome metabólico. Conclusión: El grupo con síndrome metabólico presentan alteraciones metabólicas significativas superiores e inflamación en comparación con el grupo sin síndrome metabólico. La circunferencia de cintura se considera un predictor medida antropométrica del síndrome metabólico en adolescentes obesos, siendo útil en la práctica clínica.

Beneficial effects of a multifaceted 1-year lifestyle intervention on metabolic abnormalities in obese adolescents with and without sleep-disordered breathing.

Obesity is considered a chronic subinflammatory disease and is a risk factor for many diseases such as sleep-disordered breathing (SDB). Although the interaction between obesity and sleep has been explored, not much is known about SDB in the adolescent population. Thus, the aims of this study were, first, to verify the effect of 1 year of interdisciplinary therapy on inflammatory markers in SDB and without SDB and, second, to investigate the influence of SDB on the result of the therapy by comparing these groups. A total of 36 obese adolescents were enrolled; however, only 24 completed the therapy (SDB group, n=12; non-SDB obese group, n=12). Sleep, anthropometric, metabolic, and inflammatory profiles were evaluated at baseline and after the treatment. In both groups, the therapy was able to improve all anthropometric variables. Metabolic parameters such as insulin, homeostasis model assessment (HOMA), and quantitative insulin sensitivity check index (QUICKI) were significantly improved only in non-SDB group. In both groups, the inflammatory state was significantly improved by the reduction in the leptin/adiponectin ratio. After the intervention, both groups no longer presented the hyperleptinemic state, favoring not only the inflammatory state, but also neuroendocrine regulation. Regarding the sleep parameter, the SDB group improved significantly in all respiratory events, and after therapy only four patients remained with SDB. Furthermore, there was an increase in sleep time. The lifestyle intervention was able to improve anthropometric, metabolic, and inflammatory parameters in both groups; however, the presence of SDB impaired better results. The data supported that the inclusion of SDB in the metabolic syndrome because of the link shown between them.

The high glycemic index diet was an independent predictor to explain changes in agouti-related protein in obese adolescents / La dieta de alto índice glucémico es un predictor independiente para explicar los cambios en la proteína relacionada al agouti en adolescentes obesos

The high glycemic index diet was an independent predictor to explain changes in agouti-related protein in obese adolescents. Background & Aims: The role of diet glycemic index (GI) in the control of orexigenic and anorexigenic factors of the energy balance is still not clear. The present study aimed to assess whether the habitual diet, according to different GI foods, exerts influence on regulation of energy balance markers and the effects of interdisciplinary intervention in obese adolescents. Methods: A total of 55 obese adolescents, aged from 14 to 19 years, were submited to one year of interdisciplinary therapy and were divided in two groups, according to the predominant dietary pattern of food intake: high-GI group (H-GI; n = 29) and moderate/low-GI group (M/L-GI; n = 26). Results: The concentration of orexigenic factor AgRP (p < 0.01), visceral fat (p=0.04) and visceral/subcutaneous ratio (p = 0.03) were higher in the group of H-GI when compared with M/L-GI group. Moreover, the habitual consumption of H-GI foods was an independent predictor to explain changes in AgRP concentrations. After one year of interdisciplinary therapy, the adolescents presented significant reductions in body weight, total body fat (%), visceral and subcutaneous fat and HOMA-IR, as well as a significant increase of fat free mass (%). Conclusions: Our results may suggest that habitual H-GI diet could upregulate orexigenic pathways, contributing to vicious cycle between undesirable diets, deregulates energy balance and predispose to obesity. One the other hand, one year of interdisciplinary therapy can significant improves metabolic profile and central obesity in adolescents (AU)

La Dieta de alto índice glucémico es un predictor independiente para explicar los cambios en la proteína relacionada al agouti en adolescentes obesos. Introducción y objetivos: El papel de la dieta de índice glucémico (GI) en el control de los factores orexigénicos y anorexígenos del balance de energía todavía no está claro. El presente estudio tuvo como objetivo evaluar si la dieta habitual, de acuerdo con diferentes alimentos con IG, ejerce influencia sobre la regulación de los marcadores del balance de energía y los efectos de la intervención interdisciplinaria en adolescentes obesos. Métodos: Un total de 55 adolescentes obesos, con edades de 14 a 19 años, han sido sometidos a un año de tratamiento interdisciplinario y se dividieron en dos grupos, de acuerdo al patrón de dieta predominante de la ingesta de alimentos: el grupo IG alto (H-GI; n = 29) y GI moderada/bajo grupo (M/L-GI, n = 26). Resultados: La concentración de orexigenic factor de AgRP (p < 0,01), la grasa visceral (p = 0,04) y la relación visceral/subcutánea (p = 0,03) fueron mayores en el grupo de H-GI en comparación con el grupo M/L-GI. Por otra parte, el consumo habitual de alimentos H-GI fue un predictor independiente para explicar los cambios en las concentraciones de AgRP. Después de un año de tratamiento interdisciplinario, los adolescentes presentan una reducción significativa en el peso corporal, la grasa corporal total (%), visceral y la grasa subcutánea y el HOMA-IR, así como un aumento significativo de la masa libre de grasa (%). Conclusiones: Nuestros resultados pueden sugerir que la dieta H-GI habitual podría upregulate vías orexigénicos, contribuyendo al círculo vicioso entre las dietas indeseables, desregula el equilibrio energético y predisponen a la obesidad. Uno por otro lado, un año de tratamiento interdisciplinario puede perfil metabólico mejora significativa y la obesidad central en los adolescentes (AU)

Multidisciplinary approach to the treatment of obese adolescents: effects on cardiovascular risk factors, inflammatory profile, and neuroendocrine regulation of energy balance.

The prevention of obesity and health concerns related to body fat is a major challenge worldwide. The aim of this study was to investigate the role of a medically supervised, multidisciplinary approach, on reduction in the prevalence of obesity related comorbidities, inflammatory profile, and neuroendocrine regulation of energy balance in a sample of obese adolescents. A total of 97 postpuberty obese adolescents were enrolled in this study. Body composition, neuropeptides, and adipokines were analysed. The metabolic syndrome was defined by the International Diabetes Federation (IDF). The abdominal ultrasonography was performed to measure visceral, subcutaneous fat and hepatic steatosis. All measures were performed at baseline and after one year of therapy. The multidisciplinary management promoted the control of obesity reducing body fat mass. The prevalence of metabolic syndrome, asthma, nonalcoholic fatty liver disease (NAFLD), binge eating, and hyperleptinemia was reduced. An improvement in the inflammatory profile was demonstrated by an increase in anti-inflammatory adiponectin and reduction in proinflammatory adipokines, plasminogen activator inhibitor-1, interleukin-6 concentrations, and in the Lep/Adipo ratio. Moreover, a reduction in the AgRP and an increase in the alfa-MSH were noted. The multidisciplinary approach not only reduced obesity but also is efficacious in cardiovascular risk factors, inflammatory profile, and neuroendocrine regulation of energy balance.

Aerobic training (AT) is more effective than aerobic plus resistance training (AT+RT) to improve anorexigenic/orexigenic factors in obese adolescents.

BACKGROUND: The regulation of energy balance is influenced by physical exercise. Although some studies show a stimulation of hormones related to food intake, others show that exercise provides satiety. AIM: The aim of this study was to compare the effects of aerobic training (AT) and aerobic plus resistance training (AT+RT) on anorexigenic and orexigenic factors in obese adolescents undergoing interdisciplinary weight loss therapy. METHODS: A total of 26 obese adolescents, aged 15-19 years with BMI≥P95 were submitted to 12 months of interdisciplinary intervention (clinical support, nutrition, psychology and physical exercise) and divided into two groups, aerobic training (AT) (n=13) or aerobic plus resistance training (AT+RT) (n=13), which were matched according to gender and body mass. Blood samples were collected to analyze orexigenic factors (AgRP, NPY, MCH) and the anorexigenic factor alpha-MSH. RESULTS: The AT and AT+RT groups significantly reduced body mass, body mass index and body fat mass (kg) during the therapy. The AT group showed no significant changes in body lean mass (kg), whereas the AT+RT group showed an increase in body lean mass (kg) during the interdisciplinary intervention. There was an increase in AgRP levels (ng/ml) only in the AT+RT group after 6 months of interdisciplinary intervention compared with baseline condition. Conversely, α-MSH levels (ng/ml) increased only in the AT group after 12 months of interdisciplinary intervention compared with baseline condition. CONCLUSION: Aerobic training (AT) as part of an interdisciplinary therapy is more effective than aerobic plus resistance training (AT+RT) to improve secretion of anorexigenic/orexigenic factors in obese adolescents.

Resistência insulínica pode prejudicar a redução da espessura mediointimal em adolescentes obesos / Insulin resistance can impair reduction on carotid intima-media thickness in obese adolescents

FUNDAMENTO: O processo aterosclerótico no nível endotelial começa em idade precoce e parece estar associado com a obesidade e suas comorbidades como a resistência insulínica. OBJETIVO: O objetivo deste estudo foi verificar a influência da resistência insulínica em marcadores inflamatórios e subclínicos de aterosclerose em adolescentes obesos. MÉTODOS: Sessenta e seis adolescentes obesos pós-púberes foram divididos em dois grupos de acordo com o índice de resistência insulínica estimado pelo Modelo de Avaliação da Homeostase (HOMA-RI): com resistência insulínica (RI) n = 39 e sem resistência insulínica (NRI) n = 27, e foram submetidos a uma intervenção interdisciplinar ao longo de um ano. A espessura mediointimal da artéria carótida comum (EMIC), e o tecido adiposo visceral e subcutâneo foram determinados por ultrassonografia. A composição corporal, pressão arterial, índice HOMA-RI, perfil lipídico e as concentrações de adipocinas [leptina, adiponectina, e inibidor do ativador do plasminogênio-1 (PAI-1)] foram analisados antes e após a terapia. RESULTADOS: Ambos os grupos apresentaram melhoras significativas na composição corporal, estado inflamatório (redução da concentração de leptina e PAI 1; aumento de adiponectina plasmática) e redução da EMIC. Apenas o grupo NRI mostrou correlação positiva entre as alterações na gordura visceral (∆Visceral) e mudanças na EMIC (∆ EMIC) (r = 0,42, p < 0,05). A análise por regressão linear simples revelou o ∆Visceral ser um preditor independente para a redução da EMIC nesse grupo (R2 ajustado = 0,14, p = 0,04). Os valores finais da EIMC permaneceram significativamente maiores no grupo RI, quando comparado com grupo NRI. CONCLUSÃO: A presença de resistência insulínica pode prejudicar mudanças na EMIC levando ao desenvolvimento precoce da aterosclerose em adolescentes obesos submetidos a uma intervenção interdisciplinar.

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Insulin resistance can impair reduction on carotid intima-media thickness in obese adolescents.

BACKGROUND: The atherosclerotic process at the endothelial level begins in early ages and seems to be associated with obesity and its comorbidities as insulin resistance. OBJECTIVE: The aim of this study was to verify the influence of insulin resistance on inflammatory and subclinical markers of atherosclerosis in obese adolescents. METHODS: Sixty-six post-pubescent obese adolescents were divided in two groups according to homeostasis model assessment of insulin resistance (HOMA-IR) measurement: with insulin resistance (IR) n=39 and without insulin resistance (NIR) n=27, and submitted to an interdisciplinary intervention over the course of 1 year. Common carotid artery intima-media thickness (cIMT), visceral and subcutaneous adipose tissue was determined by ultrasound. Body composition, blood pressure, HOMA-IR, lipid profile and adipokines concentrations [leptin, adiponectin, and plasminogen activator inhibitor type (PAI-1)] were analyzed before and after the therapy. RESULTS: Both groups presented significant improvements in body composition, inflammatory state (reduction of leptin and PAI-1 concentration; increasing of plasma adiponectin) and reduction of cIMT. Only NIR group showed positive correlation between changes in visceral fat (∆Visceral) and changes in cIMT (∆ cIMT) (r = 0.42; p < 0.05). Simple linear regression analyze revealed ∆Visceral to be an independent predictor to reduction of cIMT in this group (R2 adjusted = 0.14, p = 0.04). The final values of cIMT remained significantly higher in IR group when compared to NIR group. CONCLUSION: The presence of insulin resistance can impair changes in cIMT leading to early development of atherosclerosis in obese adolescents submitted to an interdisciplinary intervention..

Obese adolescents with eating disorders: analysis of metabolic and inflammatory states.

OBJECTIVE: The purpose of the present investigation was to compare the effect of interdisciplinary therapy on the physical and metabolic profiles, including body composition, insulin resistance and sensitivity as well as adiponectin and leptin concentrations, of obese adolescents with and without eating disorder symptoms. METHODS: A total of 83 obese adolescents (28 with and 55 without eating disorder symptoms) were enrolled for 1 year of interdisciplinary weight-loss therapy (clinical, nutritional, exercise, physiotherapy and psychological). Bulimic and binge eating symptoms were measured by the Bulimic Investigatory Test, Edinburgh, and the Binge Eating Scale, respectively. Leptin and adiponectin concentrations were measured with enzyme-linked immunosorbent assay kits. Visceral and subcutaneous fat were assessed by ultrasonography. RESULTS: Both groups demonstrated improved body mass, body mass index, body fat (%), lean mass, visceral fat, subcutaneous fat, homeostasis model assessment insulin-resistance index (HOMA-IR), quantitative insulin sensitivity check index, total cholesterol, LDL-cholesterol, VLDL, triglycerides, adiponectin and leptin concentrations after therapy. We found a positive correlation between leptin concentrations and subcutaneous fat in the control group and a negative correlation between adiponectin concentrations and HOMA-IR and fat mass (%). The prevalence of obese adolescents with eating disorders was reduced by 89% after 1 year of interdisciplinary therapy. CONCLUSION: The eating disorder symptoms did not impair the metabolic state during weight loss therapy of obese adolescents. Additionally, long-term interdisciplinary therapy was effective in reducing the chances of developing several co-morbidities in both groups.

Long-term effects of aerobic plus resistance training on the metabolic syndrome and adiponectinemia in obese adolescents.

The metabolic syndrome is an emerging clinical problem and different kinds of interventions have emphasized that healthy eating and exercise are crucial to its control. The aim of this study was to identify whether aerobic training plus resistance training (AT+RT) is more effective than AT on improving features of the metabolic syndrome and adiponectinemia in obese adolescents. A total of 30 adolescents (aged 15-19 years, body mass index ≥95 percentile) were enrolled in the program. All patients were diagnosed with the metabolic syndrome and submitted to 1 year of interdisciplinary intervention. They were divided into two groups: AT (n=15) and AT+RT (n=15). Blood samples were collected to analyze glycemia and lipid profiles. Adiponectin was measured by enzyme-linked immunosorbent assay, and insulin resistance was measured by homeostasis model assessment of insulin resistance index. After short- and long-term intervention, both groups presented a significant reduction in body mass, body mass index, fat mass, and visceral fat. Indeed, the AT+RT group had significantly higher changes throughout the intervention in body composition, total cholesterol, waist circumference, glucose, and adiponectin. Although important clinical parameters were ameliorated with AT, the AT+RT group showed more effective improvements in metabolic profiles and adiponectinemia. These findings suggest a clinical role of AT+RT in the control of metabolic syndrome in pediatric populations.

Visceral fat decreased by long-term interdisciplinary lifestyle therapy correlated positively with interleukin-6 and tumor necrosis factor-α and negatively with adiponectin levels in obese adolescents.

The purpose of this study was to assess the level of cytokine expression in correlation with visceral and subcutaneous fat in obese adolescents admitted to long-term interdisciplinary weight loss therapy. The study was a longitudinal clinical intervention of interdisciplinary therapy. Adolescents (18, aged 15-19 years) with body mass indexes greater than the 95th percentile were admitted and evaluated at baseline and again after 1 year of interdisciplinary therapy. Visceral and subcutaneous fat was analyzed by ultrasonography. Blood samples were collected to analyze tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), and adiponectin concentrations that were measured by enzyme-linked immunosorbent assay. The most important finding in the present investigation is that the long-term interdisciplinary lifestyle therapy decreased visceral fat. Positive correlations between IL-6 levels and visceral fat (r = 0.42, P < .02) and TNF-α levels and visceral fat (r = 0.40, P < .05) were observed. Negative correlations between TNF-α levels and subcutaneous fat (r = -0.46, P < .01) and adiponectin levels and subcutaneous fat (r = -0.43, P < .03) were also observed. In addition, we found a positive correlation between TNF-α levels and the visceral to subcutaneous fat ratio (r = 0.42, P < .02) and a negative correlation between adiponectin level and the visceral to subcutaneous fat ratio (r = -0.69, P < .001). Despite the limitation of sample size, our results indicate that the observed massive weight loss (mainly visceral fat) was highly correlated with a decreased inflammatory state, suggesting that the interdisciplinary therapy was effective in decreasing inflammatory markers.

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.

The role of nutritional profile in the orexigenic neuropeptide secretion in nonalcoholic fatty liver disease obese adolescents.

BACKGROUND: Little progress has been made to identify the central neuroendocrine pathway involved in the energy intake control in nonalcoholic fatty liver disease (NAFLD) patients. OBJECTIVE: To assess the influence of orexigenic neuropeptides in the nutritional aspects of NAFLD obese adolescents submitted to a long-term interdisciplinary approach. METHODS: Fifty adolescents aged 15-19 years, with body mass index at least 95th percentile, consisting of 25 patients without NAFLD and 25 with NAFLD. The NAFLD diagnosis was determined by ultrasonography. Blood samples were collected to analyze glycemia, hepatic transaminases, and lipid profile. Insulin resistance was estimated by Homeostasis Model Assessment Insulin Resistance Index. Neuropeptide Y (NPY) and agouti related protein concentrations were measured by enzyme-linked immunosorbent assay. Analyses of food intake were made by 3 days recordatory inquiry. RESULTS: At baseline conditions, the patients with NAFLD had significantly higher values of body mass, body mass index, visceral fat, triglycerides, VLDL-C, and hepatic transaminases. After the long-term intervention, they presented a significant reduction in these parameters. In both the groups, it was observed a significant decrease in energy intake, macronutrients and dietetic cholesterol. Only the patients with NAFLD presented a positive correlation between the saturated fatty acids intake and the orexigenic neuropeptides NPY and agouti related protein, and carbohydrate with NPY. Indeed, it was observed a positive correlation between energy intake, lipid (%) and saturated fatty acids with visceral fat accumulation. CONCLUSION: Our findings showed an important influence of diet composition in the orexigenic system, being essential consider that the excessive saturated fatty acids intake could be a determinant factor to increase nonalcoholic fatty liver disease.