Leptina, adiponectina, resistência insulínica e componentes da Síndrome Metabólica em crianças pré-púberes com excesso de peso

• Autor(a) principal: Madeira, Isabel Rey
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/8616
• topic: Adiponectin; Children; Cardiovascular diseases; Leptin; Obesity; Insulin resistance; Adiponectina; Criança; Doenças cardiovasculares; Leptina; Obesidade; Resistência à insulina; CNPQ::CIENCIAS DA SAUDE::MEDICINA::CLINICA MEDICA::PEDIATRIA

Obesity, hypertension, dyslipidemia and impaired glucose metabolism are cardiovascular risk factors, congregated under the title metabolic syndrome (MS), were insulin resistance has central role. The aims of this work are: to establish, among the cut-off values for HOMA-IR cited in the literature, the best in identifying MS in obese and overweight prepubertal children; to verify the obesity impact on MS components, leptin and adiponectin levels in prepubertal children; to verify the role of MS components, leptin and adiponectin in insulin resistance among these children. The cross-sectional work studied 112 obese, 36 overweight and 49 eutrophic prepubertal children attending the HUPE-UERJ outpatient pediatric clinic. For the first objective, it was estimated sensibility and specificity for MS of each cut off-point of HOMA-IR. A receiver operating characteristic curve was generated using these values. For the second objective, it was compared: the means of glucose (G), lipids, insulin (I), HOMA-IR, G/I relation, leptin and adiponectin from 30 obese, 31 overweight and 33 eutrophic children; the frequencies of acantosis nigricans and changes in waist, blood pressure, glucose, lipids and insulin; the correlation between body mass index z score (BMIz) and adipokines was evaluated. For the third objective, it was compared: the means of age, BMIz, lipids, leptin and adiponectin among children with and without insulin resistance; the frequencies of sex, increased waist circumference, hypertension and acantose nígricans; the correlation between those variables with HOMA-IR (multiple linear regression) and the association of them with insulin resistance (logistic regression) were evaluated. The best cut-off value of HOMA-IR for MS was 2.5 (sensibility=61%; specificity=74%). In the comparison between obese, overweight and eutrophic children, the obese differed from the others in the mean values of HDL-cholesterol and adiponectina (smaller mean values), whereas the eutrophic children differed in the mean values of I, HOMA-IR, G/I relation, and leptin (smaller mean values) (p<0.001); it was observed the same regarding the frequencies of acantose nigricans and alteration in waist and HDL-cholesterol in the obese (higher frequencies) (p<0.005); the BMIz showed a positive correlation with leptin (p<0.001) and a negative correlation with adiponectin (p=0.001); in multiple linear regression, this correlation was maintained only for leptin. In the comparison between children with and without insulin resistance, there was difference regarding the mean values of age, BMIz, HDL-cholesterol, triglycerides, leptin and adiponectina (p<0.01), and regarding the frequencies of acantose nigricans and increased waist circumference (p<0.005); in multiple linear regression age, triglycerides, leptin, sex (feminine) and acantose nigricans showed positive correlation with HOMA-IR (p<0.05), and in logistic regression, age, triglycerides, leptin and sex (feminine) showed positive association with insulin resistance (p<0.05). HOMA-IR may be useful to detect MS and the cut-off 2.5 seems to be the best. The finds provide evidence of the influence of obesity on MS components and on adipokine levels in prepbertal children, indicating that these components may contribute to the beginning of cardiovascular disease. Among the MS components, the lipids had prominent place in insulin resistance. Acantose nigricans, leptin and adiponectin also showed importance.