Relationship between bone mineral density, leptin and insulin concentration in Brazilian obese adolescents.

Despite the epidemic of adolescent obesity, the effect of obesity and hormones on bone mineral accrual during growth is poorly understood. Studies using dual-energy X-ray to examine the effect of obesity on bone mass in children and adolescents have yielded conflicting results. The aim of this study was to explore the combined and independent contributions of body mass index, body composition, leptin, insulin, glucose levels and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) to bone mineral density (BMD) and bone mineral content in a group of Brazilian obese adolescents. This study included 109 post-pubescent obese adolescents. A whole-body dual-energy X-ray absorptiometry scan was performed,using a HOLOGIC QDR4200, to determine whole-body BMD and body composition. Blood samples were collected in the outpatient clinic after an overnight fast, and evaluated for fasting blood glucose and immunoreactive insulin. Leptin levels were assessed with a radioimmunoassay kit. Insulin resistance was assessed by HOMA-IR and the quantitative insulin sensitivity check index. Our results showed that insulin levels and HOMA-IR correlated negatively with BMD and a linear regression analysis showed that serum leptin is inversely associated to BMD adjusted for body mass. In conclusion, our data support the hypothesis that leptin, insulin and HOMA-IR are inversely associated with BMD and play a significant direct role in bone metabolism.

Hormonal alteration in obese adolescents with eating disorder: effects of multidisciplinary therapy.

BACKGROUND/AIMS: Ghrelin and leptin play important roles in the physiopathology of eating disorders, starting generally in infancy and adolescence. The aim of this study was to evaluate the effects of multidisciplinary short-term therapy on ghrelin and leptin concentrations, bulimia nervosa symptoms, binge eating disorder symptoms, body composition, and visceral and subcutaneous fat in obese adolescents. METHODS: Twenty obese adolescents with simple obesity (BMI >95th percentile, 36.93 +/- 4.14, CDC) were submitted to multidisciplinary (nutrition, psychology, exercise and clinical) therapy. Plasma ghrelin and leptin concentrations were measured by radioimmunoassay. Bulimic and binge eating behaviors were measured by the Bulimic Investigation Test Edinburgh and the Binge Eating Scale, respectively. Visceral and subcutaneous fat were measured by ultrasonography and body composition by plethysmography. RESULTS: Significant reductions were observed in body weight (101.04 +/- 11.18 to 94.79 +/- 10.94 kg), BMI (36.93 +/- 4.14 to 34.27 +/- 4.78), fat% (41.96 +/- 6.28 to 39.14 +/- 7.62%), visceral fat (4.34 +/- 1.53 to 3.41 +/- 1.12 cm), leptin concentration (20.12 +/- 6.47 to 16.68 +/- 8.08 ng/ml), prevalence of bulimia nervosa (100 to 67%) and binge eating disorder symptoms (40 to 17%). CONCLUSION: Short-term multidisciplinary therapy was effective in improving body composition, visceral fat, leptinemia and eating disorders in obese adolescents.

Short- and long-term beneficial effects of a multidisciplinary therapy for the control of metabolic syndrome in obese adolescents.

Visceral fat is highly correlated with metabolic syndrome in obese adolescents. The aims of this study were to determine the prevalence of metabolic syndrome and to assess the effect of a long-term (1 year) intervention with multidisciplinary therapy in predicting metabolic syndrome among obese adolescents, as well as to compare short- with long-term therapy. Eighty-three postpuberty obese adolescents were recruited, including 37 boys (body mass index [BMI], 36.19 +/- 3.85 kg/m(2)) and 46 girls (BMI, 35.73 +/- 4.42 kg/m(2)). Body composition was measured by plethysmography using the BOD POD body composition system (version 1.69, Life Measurement Instruments, Concord, CA), and visceral fat was analyzed by ultrasound. Metabolic syndrome was determined according to the World Health Organization criteria. Patients were assigned to a weight loss multidisciplinary intervention consisting of nutritional, exercise, psychological, and clinical therapy. At the beginning of therapy, we found that 27.16% of the obese adolescents presented metabolic syndrome, whereas only 8.3% did so after intervention. Indeed, in boys, BMI (36.19 +/- 3.85 to 32.06 +/- 5.85 kg/m(2)), visceral fat (4.88 +/- 1.35 to 3.63 +/- 1.71 cm), homeostasis model assessment of insulin resistance (4.77 +/- 3.41 to 3.18 +/- 2.33), and percentage of body fat (38.24% +/- 6.54% to 30.02% +/- 13.43%) presented a statistically significant reduction; and their fat-free mass percentage increased (62.14% +/- 5.78% to 69.17% +/- 12.37%). In girls, after long-term therapy, BMI (35.73 +/- 4.42 to 33.62 +/- 3.78 kg/m(2)), visceral fat (3.70 +/- 1.40 to 2.75 +/- 1.01 cm), and percentage of body fat (46.10% +/- 5.66% to 39.91% +/- 5.59%) showed a statistically significant reduction; and their fat-free mass increased (53.61% +/- 5.65% to 59.82% +/- 5.78%). In conclusion, long-term multidisciplinary therapy was effective in promoting beneficial changes in some predictors and decreasing the prevalence of metabolic syndrome in obese adolescents.

Metabolic and nutritional profile of obese adolescents with nonalcoholic fatty liver disease.

BACKGROUND: The incidence of nonalcoholic fatty liver disease (NAFLD) is increasing due to its prevalence in obesity, diabetes, and insulin-resistance syndrome. The best treatment protocol for NAFLD has not been determined. However, there is evidence that exercise and nutritional intervention can improve and prevent it. The aim of the present study was to evaluate the dietary and metabolic profiles of obese adolescents with NAFLD who participated in a multidisciplinary program. PATIENTS AND METHODS: We studied 43 adolescents ages 15 to 19 years (17.18 +/- 1.66 years) with a body mass index (BMI) > or = 30, consisting of 30 patients without NAFLD (BMI = 35.80 +/- 3.44 kg/m2) and 13 with NAFLD (BMI = 33.47 +/- 2.34 kg/m2). The NAFLD diagnosis was determined by ultrasonography. Blood samples were collected to analyze glycemia, hepatic aminotransferase levels, and lipid profiles. Insulin resistance was measured by homeostasis model assessment insulin-resistance index (HOMA-IR). The analyses of baseline and postintervention food intake were made by a 3-day inquiry. RESULTS: At baseline conditions, the patients with NAFLD showed significant differences in body mass, BMI, and visceral and subcutaneous fat. Glucose and visceral and subcutaneous fat presented a significant reduction after treatment in patients with NAFLD. Analyzing the food intake, at baseline we observed a positive correlation between the visceral obesity and lipid consumption only in patients with NAFLD. We also observed significant decrease in energy and cholesterol consumption in patients with NAFLD after the multidisciplinary therapy. CONCLUSIONS: The intervention promoted a decrease in the prevalence of NAFLD, a significant decrease in visceral obesity, and improved HOMA-IR, glycemia, and serum lipid levels that are risk factors for NAFLD. In summary, the multidisciplinary program is essential in the treatment and prevention of NAFLD.

Platelet and leptin in obese adolescents.

OBJECTIVE: To analyze the influence of obesity status on immune cell count and concentration of the hormones cortisol and leptin, in order to establish a relationship among the variables analyzed. METHODS: We recruited 27 obese [body mass index (BMI) > or = 95th percentile] and 21 non-obese (BMI < or = 75th percentile) adolescent boys and girls, aged 15-19 years at the post-pubertal stage. BMI was calculated as body weight divided by height squared, and body composition was estimated by plethysmography in the Bod Pod system. Blood samples were collected to analyze leukocytes, neutrophils, lymphocytes, monocytes, platelets, cortisol, and leptin. The Kolmogorov-Smirnov test was performed, followed by the independent Student t test in case of normal distribution. Significance values were set at p < 0.05 and expressed as means +/- standard deviation. The statistical package SPSS for Windows version 12.0 was used. RESULTS: There was no difference between obese and non-obese adolescents in terms of leukocyte, neutrophil, lymphocyte, monocyte and cortisol serum concentrations. The group of obese adolescents presented higher platelet and leptin concentrations (p < 0.01). The prevalence of hyperleptinemia was 25.92% in the obese adolescents (15.38% in boys and 35.7% in girls). CONCLUSIONS: Obese adolescents have higher platelet and leptin concentrations in comparison with non-obese adolescents. It was also found that obese girls presented a higher prevalence of hyperleptinemia than obese boys.

Obesidade e adipocinas inflamatórias: implicações práticas para a prescrição de exercício: [revisão] / Obesity and inflammatory adipokines: practical implications for exercise prescription: [review]

A obesidade é uma doença complexa de etiologia multifacetada, com sua própria fisiopatologia, comorbidades e capacidades desabilitantes. Aceitar a obesidade como uma doença é fundamental para o seu tratamento. Atualmente, o tecido adiposo é um dos principais focos das pesquisas em obesidade, devido a uma revolução no entendimento da função biológica desse tecido desde a última década. Já está muito claro que o tecido adiposo branco secreta múltiplos peptídeos bioativos, denominados adipocinas (proteínas sintetizadas e secretadas pelo tecido adiposo). Dessa forma, o objetivo deste trabalho de revisão foi investigar a relação entre obesidade e adipocinas inflamatórias, buscando discutir o papel do exercício físico no tratamento dessa patologia. Os resultados demonstram que uma das mais importantes descobertas das pesquisas recentes em obesidade é o conceito de que ela é caracterizada por uma inflamação crônica. Dentre todas as adipocinas, sem dúvida, a IL-6, o TNF-α, a leptina (pró-inflamatórias) e a adiponectina (anti-inflamatória) vêm recebendo atenção especial da literatura especializada. O aumento da concentração dessas adipocinas promove grande impacto em diversas funções corporais que estão fortemente correlacionadas com doenças cardiovasculares. Uma vez que a obesidade é considerada uma doença inflamatória e o exercício físico modula de forma direta tais processos, é essencial que tenhamos como um dos objetivos principais de nossos programas de exercícios físicos a melhora da resposta inflamatória de obesos.

Obesity is a complex disease with a multifaceted etiology with its own physiopathology, co-morbidities and disabiliting capacities. It is crucial that obesity is acknowledged as a disease in order to treat it. Nowadays, the adipose tissue is the main focus of obesity research due to the improvement in the last decade on biological function of this tissue. It is now clear that white adipose tissue release a large amount of bioactive peptides called adipokines (which are proteins synthesized and released by adipose tissue). Thus, the aim of this review was to investigate the relationship between obesity and inflammatory adipokines, trying to discuss the role of physical exercise in the treatment of this pathology. The results have shown that one of the most important recent discoveries is the concept that obesity is characterized by a chronic inflammation state. Among all adipokines, IL-6, TNF- α, leptin (pro-inflammatory) and adiponectin (anti-inflammatory), have received special attention from the specialized literature. High concentration of these adipokines promotes impact in several body functions, which is strongly linked with cardiovascular diseases. Since obesity is considered an inflammatory disease, and exercise directly modulates this process, it is essential that one of the main aims of exercise therapies is the improvement of the inflammatory response of obese individuals.

Plaqueta e leptina em adolescentes com obesidade / Platelet and leptin in obese adolescents

OBJETIVOS: Analisar a influência de obesidade na contagem de células imunológicas e na concentração dos hormônios cortisol e leptina, a fim de estabelecer uma relação entre as variáveis analisadas. MÉTODOS: Foram recrutados 27 adolescentes obesos [índice de massa corporal (IMC) ≥ percentil 95[ e 21 não-obesos (IMC ≤ percentil 75), de ambos os sexos, com idade entre 15 e 19 anos, na fase pós-púbere. O IMC foi calculado através da divisão do peso pela altura ao quadrado e a composição corporal foi estimada por pletismografia no sistema Bod PodTM. Amostras de sangue foram colhidas para análise de leucócitos, neutrófilos, linfócitos, monócitos, plaquetas, cortisol e leptina. O teste de Kolmogorov-Smirnov foi utilizado, seguido pelo teste t de Student independente supondo distribuição normal. O nível de significância estabelecido foi p < 0,05 e expresso como média ± desvio padrão. Os dados foram analisados utilizando o programa SPSS para Windows versão 12.0. RESULTADOS: Não houve diferença entre o grupo obeso e o não-obeso na concentração sérica de leucócitos, neutrófilos, linfócitos, monócitos e cortisol. O grupo de adolescentes obesos apresentou maiores concentrações de plaquetas e leptina (p < 0,01). A prevalência de hiperleptinemia foi de 25,92 por cento nos adolescentes obesos (15,38 por cento, sexo masculino e 35,7 por cento, feminino). CONCLUSÕES: Os adolescentes obesos apresentaram maiores concentrações de plaquetas e leptina em comparação aos não-obesos. Observou-se que as adolescentes obesas apresentaram maior prevalência de hiperleptinemia do que os adolescentes obesos.

OBJECTIVE: To analyze the influence of obesity status on immune cell count and concentration of the hormones cortisol and leptin, in order to establish a relationship among the variables analyzed. METHODS: We recruited 27 obese [body mass index (BMI) ≥ 95th percentile[ and 21 non-obese (BMI ≤ 75th percentile) adolescent boys and girls, aged 15-19 years at the post-pubertal stage. BMI was calculated as body weight divided by height squared, and body composition was estimated by plethysmography in the Bod PodTM system. Blood samples were collected to analyze leukocytes, neutrophils, lymphocytes, monocytes, platelets, cortisol, and leptin. The Kolmogorov-Smirnov test was performed, followed by the independent Student t test in case of normal distribution. Significance values were set at p < 0.05 and expressed as means ± standard deviation. The statistical package SPSS for Windows version 12.0 was used. RESULTS: There was no difference between obese and non-obese adolescents in terms of leukocyte, neutrophil, lymphocyte, monocyte and cortisol serum concentrations. The group of obese adolescents presented higher platelet and leptin concentrations (p < 0.01). The prevalence of hyperleptinemia was 25.92 percent in the obese adolescents (15.38 percent in boys and 35.7 percent in girls). CONCLUSIONS: Obese adolescents have higher platelet and leptin concentrations in comparison with non-obese adolescents. It was also found that obese girls presented a higher prevalence of hyperleptinemia than obese boys.