[Diagnosis of insulin resistance by indirect methods in obese school children]. / Diagnóstico de resistencia a la insulina por métodos indirectos en escolares obesos.

UNLABELLED: Obesity leads to a deterioration of glucose tolerance and the action of insulin. The purpose of this study was to determine insulin resistance (IR) by indirect methods, and its correlation with clinical, anthropometric and biochemical variables in obese normoglycemic school children. This was a descriptive-correlational study of 72 school prepubescent children, who attended the ambulatory "El Concejo" of the University of Carabobo (UC) and at the Gastroenterology and Pediatric Nutrition service of the city hospital "Enrique Tejera" (CHET), in Valencia, Venezuela, between January-April 2011. INCLUSION CRITERIA: exogenous obesity. We assessed personal and family history, presence of Acanthosis Nigricans and nutritional and biochemical status. We found a higher percentage of IR, through the use of the QUICKI method (66.7%), followed by the HOMA (55.6%) and basal insulin (45.9%). The mean (chi) indexes of body mass and waist circumference were significantly greater (p < 0.05) in patients with IR, by HOMA and QUICKI techniques. The QUICKI method detected significant differences (p < 0.05) in the values of glycemia, basal insulin and postprandial insulin, among patients with diminished and normal insulin sensitivities. While HOMA, detected these differences (p < 0.05) in the values of glycemia and basal insulin. A statistically significant relationship was observed (p < 0.05), between the presence of Acanthosis Nigricans and IR, by the HOMA, QUICKI and basal insulin methods. In conclusion, the evaluated techniques, QUICKI, HOMA and basal insulin indexes, were most effective for detecting the IR.

Diagnóstico de resistencia a la insulina por métodos indirectos en escolares obesos / Diagnosis of insulin resistance by indirect methods in obese school children

El incremento de la adiposidad, conduce a un deterioro de la tolerancia a la glucosa y de la acción de la insulina. Se determinó la resistencia a la insulina (RI) por métodos indirectos y se correlacionó con variables clínicas, antropométricas y bioquímicas en escolares obesos normoglicémicos. Estudio descriptivo-correlacional, realizado en 72 escolares, que acudieron al ambulatorio El Concejo de la Universidad de Carabobo (UC) y al servicio de Gastroenterología y Nutrición Pediátrica de la Ciudad Hospitalaria “Enrique Tejera” (CHET), de Valencia, Venezuela, entre enero y abril de 2011. Criterio de Inclusión: obesidad exógena. Se evaluaron antecedentes personales y familiares, presencia de acantosis nigricans y valoración nutricional y bioquímica. Se encontró mayor porcentaje de RI, a través de la utilización del método QUICKI (66,7%), seguido del HOMA (55,6%) y la insulina basal (45,9%). Las medias de índice de masa corporal y circunferencia de cintura, fueron significativamente mayores (p<0,05), en pacientes con RI, estimadas por los métodos HOMA y QUICKI. El método QUICKI, detectó diferencias significativas (p<0,05), entre las glicemias e insulinas basales y entre las insulinas postprandiales, de los pacientes con sensibilidades insulínica disminuida y normal; mientras que el HOMA, detectó estas diferencias (p<0,05), en las glicemias e insulinas basales. Se observó una correlación estadísticamente significativa (p<0,05), entre la presencia de acantosis nigricans y la RI, estimada por los métodos HOMA, QUICKI e insulina basal. En conclusión, de los métodos evaluados, los índices QUICKI, HOMA y la insulina basal, fueron los más eficaces para detectar la RI.

Obesity leads to a deterioration of glucose tolerance and the action of insulin. The purpose of this study was to determine insulin resistance (IR) by indirect methods, and its correlation with clinical, anthropometric and biochemical variables in obese normoglycemic school children. This was a descriptive-correlational study of 72 school prepubescent children, who attended the ambulatory “El Concejo” of the University of Carabobo (UC) and at the Gastroenterology and Pediatric Nutrition service of the city hospital “Enrique Tejera” (CHET), in Valencia, Venezuela, between January-April 2011. Inclusion criteria: exogenous obesity. We assessed personal and family history, presence of Acanthosis Nigricans and nutritional and biochemical status. We found a higher percentage of IR, through the use of the QUICKI method (66.7%), followed by the HOMA (55.6%) and basal insulin (45.9%). The mean (c) indexes of body mass and waist circumference were significantly greater (p < 0.05) in patients with IR, by HOMA and QUICKI techniques. The QUICKI method detected significant differences (p < 0.05) in the values of glycemia, basal insulin and postprandial insulin, among patients with diminished and normal insulin sensitivities. While HOMA, detected these differences (p < 0.05) in the values of glycemia and basal insulin. A statistically significant relationship was observed (p < 0.05), between the presence of Acanthosis Nigricans and IR, by the HOMA, QUICKI and basal insulin methods. In conclusion, the evaluated techniques, QUICKI, HOMA and basal insulin indexes, were most effective for detecting the IR.

Acanthosis nigricans and insulin resistance in overweight children and adolescents.

BACKGROUND: Studies have suggested an association between the presence of acanthosis nigricans (AN) and the development of diabetes. OBJECTIVE: To investigate the association between AN and insulin resistance (IR) in overweight children and adolescents receiving care at the Center for Childhood Obesity, Campina Grande, PB. METHODS: This cross-sectional study was conducted between April 2009 and April 2010 including 194 individuals of 2 to 18 years of age receiving care within the Brazilian national health network. The presence of acanthosis nigricans was verified and anthropometric measurements were taken. The following tests were performed: insulin, triglycerides, HDL-cholesterol, glucose and homeostasis model of assessment - insulin resistance (HOMA-IR). Statistical analyses were performed using the SPSS software program, version 17.0. RESULTS: There was a greater prevalence of females (66%), brown-skinned individuals (63.4%), adolescents (61.3%) and severely obese individuals (66.5%). Acanthosis nigricans was identified in 58.2% and IR in 42.7% of the participants. Acanthosis nigricans was associated with being non-white (p = 0.003), with being an adolescent (p = 0.003) and with IR (p = 0.001). Non-white individuals, adolescents and those with insulin resistance were 5.4, 2.47 and 2.66 times more likely to have acanthosis nigricans, respectively. CONCLUSION: The results of this study indicate a need to train healthcare professionals to identify acanthosis nigricans, since this condition is associated with IR. Identifying acanthosis nigricans in childhood permits the safe and timely treatment of cardiometabolic disorders through careful monitoring and appropriate treatment.

Acanthosis nigricans and insulin resistance in overweight children and adolescents / Acantose nigricans e resistência insulínica em crianças e adolescentes com excesso de peso

BACKGROUND: Studies have suggested an association between the presence of acanthosis nigricans (AN) and the development of diabetes. OBJECTIVE: To investigate the association between AN and insulin resistance (IR) in overweight children and adolescents receiving care at the Center for Childhood Obesity, Campina Grande, PB. METHODS: This cross-sectional study was conducted between April 2009 and April 2010 including 194 individuals of 2 to 18 years of age receiving care within the Brazilian national health network. The presence of acanthosis nigricans was verified and anthropometric measurements were taken. The following tests were performed: insulin, triglycerides, HDL-cholesterol, glucose and homeostasis model of assessment - insulin resistance (HOMA-IR). Statistical analyses were performed using the SPSS software program, version 17.0. RESULTS: There was a greater prevalence of females (66%), brown-skinned individuals (63.4%), adolescents (61.3%) and severely obese individuals (66.5%). Acanthosis nigricans was identified in 58.2% and IR in 42.7% of the participants. Acanthosis nigricans was associated with being non-white (p = 0.003), with being an adolescent (p = 0.003) and with IR (p = 0.001). Non-white individuals, adolescents and those with insulin resistance were 5.4, 2.47 and 2.66 times more likely to have acanthosis nigricans, respectively. CONCLUSION: The results of this study indicate a need to train healthcare professionals to identify acanthosis nigricans, since this condition is associated with IR. Identifying acanthosis nigricans in childhood permits the safe and timely treatment of cardiometabolic disorders through careful monitoring and appropriate treatment.

FUNDAMENTOS: Estudos sugerem haver associação entre a presença de Acantose Nigricans e o desenvolvimento do diabetes. OBJETIVO: Verificar a associação entre Acantose Nigricans e Resistência Insulínica (RI) em crianças e adolescentes com excesso de peso, atendidos no Centro de Obesidade Infantil, Campina Grande-PB. MÉTODOS: Estudo transversal realizado entre abril/2009 a abril/2010, com amostra de 194 pessoas entre 2 e 18 anos, usuários do Sistema Único de Saúde. Na avaliação, foi observada a presença de AN e verificadas as medidas antropométricas. Foram realizados os exames: insulina, triglicerídeos, HDL-colesterol, glicose e HOMA-IR. As análises estatísticas foram realizadas no SPSS, 17.0. RESULTADOS: Houve maior prevalência do sexo feminino (66%), pardos (63,4%), adolescentes (61,3%) e obesos graves (66,5%). Foi identificada AN em 58,2% e RI em 42,7%. A Acantose Nigricans esteve associada à cor não-branca (p=0,003), adolescentes (p=0,003) e RI (p=0,001). Os não-brancos apresentaram chance de 5,4 vezes maior de terem Acantose Nigricans, os adolescentes, de 2,47 e os com Resistência Insulínica, de 2,66. CONCLUSÃO: Os resultados na população em estudo indicam a necessidade de treinamento voltado à identificação da Acantose Nigricans para profissionais de saúde, pois este sinal esteve associado à Resistência Insulínica. Identificar a Acantose Nigricans desde a infância permite prevenir e tratar precocemente distúrbios cardiometabólicos, através de acompanhamento criterioso e tratamento adequado.

O impacto da obesidade sobre os componentes da síndrome metabólica e as adipocitoquinas em crianças pré-púberes / Impact of obesity on metabolic syndrome components and adipokines in prepubertal children

OBJETIVO: Verificar o impacto da obesidade sobre os componentes da síndrome metabólica e sobre os níveis de adipocitoquinas em crianças pré-púberes. MÉTODOS: Estudo transversal comparando 30 crianças obesas, 31 com sobrepeso e 33 eutróficas, oriundas do ambulatório de pediatria geral de um hospital universitário, quanto às médias de glicose, lipídios séricos, insulina, HOMA-IR (homeostasis model assessment-insulin resistance), relação glicose/insulina, adiponectina e leptina. Compararam-se as frequências de acantose nigricans e das alterações de cintura, pressão arterial, glicose, lipídios séricos e insulina. Avaliou-se a correlação entre escore z de índice de massa corporal (IMC) e adipocitoquinas. RESULTADOS: Houve diferença nas médias dos obesos, quanto a HDL-colesterol e adiponectina, e nas dos eutróficos, quanto a insulina, HOMA-IR, relação glicose/insulina e leptina (p < 0,001). O mesmo ocorreu em relação às frequências dos obesos quanto a acantose nigricans e alteração de cintura e HDL-colesterol (p < 0,005). O escore z de IMC se correlacionou positivamente com leptina (p < 0,001) e negativamente com adiponectina (p = 0,001). Na regressão linear múltipla, esta correlação se manteve apenas para leptina; o HDL-colesterol se correlacionou com adiponectina (p = 0,007) e o HOMA-IR com ambas (p < 0,05). CONCLUSÃO: Os achados comprovam a influência da obesidade sobre os componentes da síndrome metabólica e sobre os níveis de adipocitoquinas já nas crianças pré-púberes e apontam para a importância destas na gênese da doença cardiovascular.

OBJECTIVE: To verify the impact of obesity on metabolic syndrome components and adipokine levels in prepubertal children. METHODS: This cross-sectional study compared 30 obese, 31 overweight and 33 eutrophic children attending a university hospital-based outpatient pediatric clinic. Parameters assessed included glucose, serum lipids, insulin, homeostasis model assessment-insulin resistance (HOMA-IR), glucose/insulin relation, adiponectin, and leptin. We compared the frequency of acanthosis nigricans and changes in waist, blood pressure, glucose, serum lipids, and insulin. The correlation between body mass index (BMI) z score and adipokines was evaluated. RESULTS: Among obese children, there was a difference in the mean values of HDL cholesterol and adiponectin, whereas among the eutrophic children, there was a difference in the mean values of insulin, HOMA-IR, glucose/insulin relation, and leptin (p < 0.001). A difference was also observed regarding the frequency of acanthosis nigricans and alteration in waist and HDL cholesterol (p < 0.005) in the obese group. The BMI z score 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; HDL-cholesterol correlated with adiponectin (p = 0.007) and HOMA-IR correlated with both variables (p < 0.05). CONCLUSION: These findings provide evidence of the influence of obesity on metabolic syndrome components and on adipokine levels in prepubertal children, indicating that these components may contribute to the beginning of cardiovascular diseases.

Impact of obesity on metabolic syndrome components and adipokines in prepubertal children.

OBJECTIVES: To verify the impact of obesity on metabolic syndrome components and adipokine levels in prepubertal children. METHODS: This cross-sectional study compared 30 obese, 31 overweight and 33 eutrophic children attending a university hospital-based outpatient pediatric clinic. Parameters assessed included glucose, serum lipids, insulin, homeostasis model assessment-insulin resistance (HOMA-IR), glucose/insulin relation, adiponectin, and leptin. We compared the frequency of acanthosis nigricans and changes in waist, blood pressure, glucose, serum lipids, and insulin. The correlation between body mass index (BMI) z score and adipokines was evaluated. RESULTS: Among obese children, there was a difference in the mean values of HDL cholesterol and adiponectin, whereas among the eutrophic children, there was a difference in the mean values of insulin, HOMA-IR, glucose/insulin relation, and leptin (p < 0.001). A difference was also observed regarding the frequency of acanthosis nigricans and alteration in waist and HDL cholesterol (p < 0.005) in the obese group. The BMI z score 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; HDL-cholesterol correlated with adiponectin (p = 0.007) and HOMA-IR correlated with both variables (p < 0.05). CONCLUSIONS: These findings provide evidence of the influence of obesity on metabolic syndrome components and on adipokine levels in prepubertal children, indicating that these components may contribute to the beginning of cardiovascular diseases.

Prevalence of insulin resistance and its association with metabolic syndrome criteria among Bolivian children and adolescents with obesity.

BACKGROUND: Obesity is a one of the most common nutritional disorder worldwide, clearly associated with the metabolic syndrome, condition with implications for the development of many chronic diseases. In the poorest countries of Latin America, malnourishment is still the most prevalent nutritional problem, but obesity is emerging in alarming rates over the last 10 years without a predictable association with metabolic syndrome. The objective of our study was to determine the association between insulin-resistance and components of the metabolic syndrome in a group of Bolivian obese children and adolescents. The second objective was determining the relation of acanthosis nigricans and insulin-resistance. METHODS: We studied 61 obese children and adolescents aged between 5 and 18 years old. All children underwent an oral glucose tolerance test and fasting blood sample was also obtained to measure insulin, HDL, LDL and triglycerides serum level. The diagnosis of metabolic syndrome was defined according to National Cholesterol Education Program-Adult Treatment Panel (NCEP-ATP III) criteria adapted for children. RESULTS: Metabolic syndrome was found in 36% of the children, with a higher rate among males (40%) than females (32.2%) (p = 0.599). The prevalence of each of the components was 8.2% in impaired glucose tolerance, 42.6% for high triglyceride level, 55.7% for low levels of high-density lipoprotein cholesterol, and 24.5% for high blood pressure. Insulin resistance (HOMA-IR > 3.5) was found in 39.4% of the children, with a higher rate in males (50%) than females (29%). A strong correlation was found between insulin resistance and high blood pressure (p = 0.0148) and high triglycerides (p = 0.002). No statistical significance was found between the presence of acanthosis nigricans and insulin resistance. CONCLUSION: Metabolic syndrome has a prevalence of 36% in children and adolescent population in the study. Insulin resistance was very common among children with obesity with a significant association with high blood pressure and high triglycerides presence.

Comparison of metformin versus rosiglitazone in patients with Acanthosis nigricans: a pilot study.

BACKGROUND: Acanthosis nigricans (AN) is a skin condition commonly present on the neck of obese subjects. Obesity is often accompanied by insulin resistance and/or hyperinsulinemia. Metformin and rosiglitazone are 2 pharmacologic agents useful in conditions characterized by insulin resistance. OBJECTIVE: The aim of our study was to compare the efficacy of metformin versus rosiglitazone on AN lesions of the neck as well as their effects on metabolic and anthropometric variables. METHODS: This 12-week randomized, open-label pilot study involved overweight or obese subjects with AN treat with either metformin (n=4) or rosiglitazone (n=3). RESULTS: Only the rosiglitazone group showed a significant reduction in insulin levels. No effect on the severity of AN was observed, but modest improvements of skin texture occurred in both treatment groups. CONCLUSIONS: Metformin and rosiglitazone were well-tolerated. Although efficacy on skin lesions was very modest, their use in acanthotic subjects might be useful during longer treatment periods.

[Effect of chronic blockade of the opiodergic receptor on insulin resistance in a hyperandrogenic woman]. / Efecto del bloqueo crónico del receptor opioidergico sobre la insulino-resistencia en una mujer hiperandrogénica.

We report a woman with insulin resistance associated with hyperandrogenism and acanthosis nigricans (HAIR-AN syndrome) treated during 30 days with the prolonged action opioid antagonist Naltrexone. During its administration, decreases in basal blood glucose and serum insulin, insulin and glucose response to a glucose load and plasma testosterone were observed. These findings suggest that opioid activity could play a critical role in the physiopathology of hyperinsulinemia in hyperandrogenic women.

[Amenorrhea, insulin resistance and acanthosis nigricans. A hyperandrogenic and a normoandrogenic clinical forms]. / Amenorrea, resistencia insulínica y acantosis nigricans. Una forma clínica hiperandrogenica y otra normoandrogenica.

Two cases of HAIR-AN syndrome (hyperandrogenism, insulin resistance and acanthosis nigricans) are presented. The first case corresponds to a female with a systemic lupus erythematosus and acanthosis nigricans in which an insulin resistance was documented; the patient was in amenorrhea with severe hypoestrogenism, although she did not have clinical signs of hyperandrogenism and serum androgen levels were normal. This case corresponds to a HAIR-AN syndrome associated to autoimmune diseases or type A of Kahn. The second case is a young female with clinical signs of hyperandrogenism associated to high testosterone levels; she had acanthosis nigricans and fasting and postprandial hyperinsulinemia. Probably, this case corresponds to a type A or C HAIR-AN syndrome in which there is a decrease in the number of insulin receptors or a post receptor defect in insulin action.

Role of obesity and hyperinsulinemia in the insulin resistance of obese subjects with the clinical triad of polycystic ovaries, hirsutism and acanthosis nigricans.

The insulin resistance of 4 nonobese and 8 obese patients with polycystic ovaries, hirsutism and benign acanthosis nigricans, and of 6 'obese normal' apart from obesity and 10 normal female subjects was evaluated by means of an intravenous insulin tolerance test and by measuring basal and insulin responses to an oral glucose load. The patients with polycystic ovaries, hirsutism and acanthosis had a decreased hypoglycemic response to exogenous insulin. The subjects with polycystic ovaries presented a significantly greater mean glucose response area for the same or greater mean insulin response area than the obese or nonobese normal subjects. The insulin resistance in the patient with polycystic ovaries, hirsutism and acanthosis nigricans could not be exclusively ascribed to a reduced receptor number, but also appeared to be due to a simultaneous postbinding defect probably related to the high insulin levels in patients with polycystic ovaries be they obese or not. The elevated plasma androgens and the presence of acanthosis found in these patients are likely also related to the hyperinsulinemia. To evaluate the influence of obesity, obese and nonobese patients with acanthosis nigricans and polycystic ovaries were compared. Higher insulin levels were found in the thin subjects, which could explain their greater insulin resistance and more severe hyperandrogenism. The comparison between obese patients with and those without acanthosis nigricans and polycystic ovaries suggested that, despite similar insulin levels, the greater known duration of obesity (probably also of the hyperinsulinemia) of the former was a possible explanation for their more intense insulin resistance and higher testosterone levels.