Relations between asthma and obesity: an analysis of multiple factors / Relações entre asma e obesidade: análise de múltiplos fatores

ABSTRACT Objective: Asthma and obesity are prevalent and interrelated diseases. In the pediatric population, the effect of systemic inflammation associated to obesity, leading to inflammation of the airways, is currently controversial. Our aim was to compare inflammatory, clinical and spirometric patterns between children with asthma and obesity and those within the normal weight status range. Methods: A total of 79 boys and girls from 6 to 10 years old were selected and divided into four groups: obese asthmatics, non-obese asthmatics, obese non-asthmatics, and non-obese non-asthmatics. In addition to collecting clinical and anthropometric data, all children underwent spirometry and skin prick tests for inhalant allergens. Blood samples for measurement of cytokines and adipokines were also collected. Results: Obese asthmatics had significantly worse control of asthma than non-obese asthmatics (OR 4.9; 95%CI 1.1‒22.1), regardless of sex, physical activity and atopy. No differences in spirometry, Th1 and Th2 cytokines and adipokines levels were observed among the four groups. The prick tests were positive in 81.8 and 80% of non-obese asthmatics and obese asthmatics, respectively. Conclusions: The degree of control of asthma was significantly lower in the obese group, regardless of the findings of no differences in spirometry. Extra-pulmonary factors could be responsible for this symptomatic profile. High positivity of skin test in both groups, which is considered a good marker of atopy, shows a preponderant atopic component in the genesis of asthma, both in children with obesity and in those within the normal weight status.

RESUMO Objetivo: A asma e a obesidade são doenças prevalentes e inter-relacionadas. Na população pediátrica, o efeito da inflamação sistêmica associada à obesidade, levando à inflamação das vias aéreas, é controverso. Nosso objetivo foi comparar padrões inflamatórios, clínicos e espirométricos entre crianças obesas e aquelas com peso normal. Métodos: Setenta e nove meninos e meninas de 6‒10 anos de idade foram selecionados e divididos em quatro grupos: asmáticos obesos, asmáticos não obesos, não asmáticos obesos e não asmáticos não obesos. Além de dados clínicos e antropométricos, todas as crianças foram submetidas a espirometria e testes cutâneos para alérgenos inalantes. Também foram coletadas amostras de sangue para dosagem de citocinas e adipocinas. Resultados: Obesos asmáticos tiveram um controle significativamente pior da asma do que os não obesos (RP 4,9; IC95% 1,1‒22,1), independentemente do sexo, atividade física e atopia. Não foram observadas diferenças nos níveis de espirometria, citocinas Th1 e Th2 e adipocinas entre os quatro grupos. Os testes cutâneos foram positivos em 81,8 e 80% dos não obesos asmáticos e obesos asmáticos, respectivamente. Conclusões: O grau de controle da asma foi significativamente menor no grupo obeso, apesar de não ter havido diferenças nos achados espirométricos. Esse resultado sugere que fatores extrapulmonares podem ser responsáveis por esse perfil sintomático. A alta positividade do teste cutâneo nos dois grupos, considerado um bom marcador de atopia, demonstrou o componente atópico como preponderante na gênese da asma, tanto em crianças com obesidade quanto naquelas com peso normal.

RELATIONS BETWEEN ASTHMA AND OBESITY: AN ANALYSIS OF MULTIPLE FACTORS.

OBJECTIVE: Asthma and obesity are prevalent and interrelated diseases. In the pediatric population, the effect of systemic inflammation associated to obesity, leading to inflammation of the airways, is currently controversial. Our aim was to compare inflammatory, clinical and spirometric patterns between children with asthma and obesity and those within the normal weight status range. METHODS: A total of 79 boys and girls from 6 to 10 years old were selected and divided into four groups: obese asthmatics, non-obese asthmatics, obese non-asthmatics, and non-obese non-asthmatics. In addition to collecting clinical and anthropometric data, all children underwent spirometry and skin prick tests for inhalant allergens. Blood samples for measurement of cytokines and adipokines were also collected. RESULTS: Obese asthmatics had significantly worse control of asthma than non-obese asthmatics (OR 4.9; 95%CI 1.1‒22.1), regardless of sex, physical activity and atopy. No differences in spirometry, Th1 and Th2 cytokines and adipokines levels were observed among the four groups. The prick tests were positive in 81.8 and 80% of non-obese asthmatics and obese asthmatics, respectively. CONCLUSIONS: The degree of control of asthma was significantly lower in the obese group, regardless of the findings of no differences in spirometry. Extra-pulmonary factors could be responsible for this symptomatic profile. High positivity of skin test in both groups, which is considered a good marker of atopy, shows a preponderant atopic component in the genesis of asthma, both in children with obesity and in those within the normal weight status.

Microcirculation, Adiposity, and Traditional and Emerging Cardiovascular Risk Factors in Prepubertal Children.

PURPOSE: Previous studies have shown that microvascular dysfunction (MD) is associated with a number of cardiovascular risk factors, including obesity. Few studies have assessed microvascular reactivity in children, and in most of these, results were confounded by the effects of puberty. Our aim was to establish whether MD is already present in obese prepubertal children. METHODS: This cross-sectional study included 52 obese, 18 overweight, and 28 eutrophic children, with a mean ± standard deviation age of 7.44 ± 1.22 years. We evaluated cardiovascular risk factors and nutritive microvascular function by using nailfold dynamic videocapillaroscopy and determined functional capillary density (FCD), red blood cell velocity at resting conditions (RBCV) and at peak (RBCVmax), and time to reach peak velocity during the post-occlusive reactive hyperemic response following 1 minute ischemia. RESULTS: On univariate analysis, differences in microvascular reactivity were not observed among the groups. Obese and overweight children had significantly higher scores than eutrophic children for the following parameters: body mass index, waist circumference, waist-to-height ratio, mean arterial pressure, homeostasis model assessment for insulin resistance, levels of insulin, leptin, glucose, triglycerides, total cholesterol, uric acid, and C-reactive protein. Multivariate analysis demonstrated the association between metabolic, anthropometric, and microvascular variables, stratified according to the degree of adiposity and body fat distribution. CONCLUSIONS: Univariate analysis did not show any difference in microvascular reactivity between groups but, by testing these variables by multivariate means, we noticed a common and direct variation between cardiovascular/metabolic risk factors and microvascular reactivity occurring early in life.

Association between cardiovascular risk factors and carotid intima-media thickness in prepubertal Brazilian children.

BACKGROUND: Early exposure to cardiovascular risk factors creates a chronic inflammatory state that could damage the endothelium followed by thickening of the carotid intima-media. OBJECTIVE: To investigate the association of cardiovascular risk factors and thickening of the carotid intima. SUBJECTS/METHODS: Media in prepubertal children. In this cross-sectional study, carotid intima-media thickness (cIMT) and cardiovascular risk factors were assessed in 129 prepubertal children aged from 5 to 10 year. Association was assessed by simple and multivariate logistic regression analyses. RESULTS: In simple logistic regression analyses, body mass index (BMI) z-score, waist circumference, and systolic blood pressure (SBP) were positively associated with increased left, right, and average cIMT, whereas diastolic blood pressure was positively associated only with increased left and average cIMT (p<0.05). In multivariate logistic regression analyses increased left cIMT was positively associated to BMI z-score and SBP, and increased average cIMT was only positively associated to SBP (p<0.05). CONCLUSIONS: BMI z-score and SBP were the strongest risk factors for increased cIMT.

Nonobese Young Females with Polycystic Ovary Syndrome have Nutritive Microvascular Dysfunction: A Pilot Study.

OBJECTIVE: To investigate nutritive microvascular function in young nonobese females with polycystic ovary syndrome (PCOS) and to correlate microvascular reactivity with sex steroids, inflammatory markers, and metabolic variables. METHODS: Fourteen nonobese females with PCOS (24.6 ± 2.7 years, body mass index [BMI] 23.7 ± 3.1 kg/m2) and 13 age- and BMI-matched controls (22.8 ± 2.3 years, 22.5 ± 3.4kg/m2) underwent anthropometric, hormonal, and microvascular evaluations. The main outcome measures were capillary density, red blood cell velocity (RBCV) at resting and peak during postocclusive reactive hyperemia (RBCVmax), and time taken to reach RBCVmax (TRBCVmax). RESULTS: Subjects with PCOS had lower RBCV and higher TRBCVmax compared to controls, respectively (0.237 [0.220-0.324] vs. 0.362 [0.297-0.382] mm/s, P<.01) and (5 [5-6] vs. 4 [3-5] s, P<.05]. The free androgen index (FAI) and sex hormone-binding globulin (SHBG) level were different between groups. FAI correlated to RBCVmax (ρ = -0.49, P<.05) and to TRBCVmax (ρ = 0.41, P<.05). SHBG correlated with RBCVmax (ρ = 0.52, P<.01) while estradiol (E2) levels correlated with RBCV (ρ = 0.80, P<.001) and RBCVmax (ρ = 0.46, P<.05). CONCLUSION: Microvascular dysfunction characterized by reduced RBCVmax and prolonged TRBCVmax was present in young, nonobese PCOS subjects. FAI was associated with observed impairments, suggesting a possible common mechanism linking sex hormones and microvascular dysfunction.

The role of metabolic syndrome components and adipokines in insulin resistance in prepubertal children.

OBJECTIVE: Insulin resistance has a central role in the pathophysiology of cardiovascular atherosclerotic disease. Adipose tissue is of capital importance in view of its production of adipokines. The present study aims to determine the association of metabolic syndrome components, which constitute risk factors for cardiovascular atherosclerotic disease, and leptin and adiponectin with insulin resistance in prepubertal children. METHODS: We conducted a cross-sectional study involving 197 children. Of these, 112 children were obese, 36 were overweight and 49 had normal weight. The association of sex, waist circumference, Acanthosis nigricans, age, BMI Z-score, serum lipids, leptin and adipocytokines with insulin resistance [defined as the homeostatic model assessment for insulin resistance (HOMA-IR) index higher than or equal to 2.5] was investigated using logistic regression. RESULTS: There was positive association of sex (female), age, BMI Z-score, triglycerides and leptin with insulin resistance (p<0.05). CONCLUSION: Among the conventional components of metabolic syndrome, the role of BMI Z-score and triglycerides stands out in insulin resistance of prepubertal children. Sex (female), age and leptin also showed to be of major importance.

Ponto de corte do índice Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) avaliado pela curva Receiver Operating Characteristic (ROC) na detecção de síndrome metabólica em crianças pré-púberes com excesso de peso / Cut-off point for Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index established from Receiver Operating Characteristic (ROC) curve in the detection of metabolic syndrome in overweight pre-pubertal children

OBJETIVO: Estabelecer, entre os pontos de corte do índice homeostatic model assessment for insulin resistance (HOMA-IR), citados na literatura, o melhor em identificar a síndrome metabólica (SM) em crianças com obesidade e sobrepeso. MÉTODOS: Foram estudadas 140 crianças pré-púberes. A definição de SM foi adaptada da International Diabetes Federation. Para cada ponto de corte de HOMA-IR foram estimados sensibilidade e especificidade, tomandose como desfecho a SM. Uma curva receiver operating characteristic (ROC) foi construída com estes valores. RESULTADOS: O grupo estudado constituiu-se de 106 crianças com obesidade (37 meninas e 69 meninos) e 34 com sobrepeso (19 meninas e 15 meninos), média de idade 6,5 ± 2,3 anos. A acurácia da curva ROC foi 72 por cento, e o melhor ponto de corte foi 2,5, com sensibilidade 61 por cento e especificidade 74 por cento. CONCLUSÃO: O índice HOMA-IR pode ser útil para detectar a SM, e o ponto de corte 2,5 mostrou-se o melhor para crianças pré-púberes com obesidade e sobrepeso.

OBJECTIVE: To establish, among the cut-off values for the homeostatic model assessment for insulin resistance index (HOMA-IR) cited in the literature, the best in identifying metabolic syndrome (MS) in obese and overweight children. METHODS: A total of 106 pre-pubertal children were studied. The definition of MS was adapted from that of the International Diabetes Federation. For each cut-off values for HOMA-IR, it was estimated sensibility and specificity for MS. A receiver operating characteristic (ROC) curve was generated using these values. RESULTS: The study included 106 obese (37 girls and 69 boys) and 34 overweight (19 girls and 15 boys) children aged 6,5 ± 2,3 years. The accuracy of the ROC curve was 72 percent, and the best cut-off value for HOMAIR was 2,5, with sensitivity of 61 percent and specificity of 74 percent. CONCLUSIONS: HOMA-IR may be useful to detect MS and the cut-off 2,5 seems to be the best in obese and overweight pre-pubertal children.

[Cut-off point for Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index established from Receiver Operating Characteristic (ROC) curve in the detection of metabolic syndrome in overweight pre-pubertal children]. / Ponto de corte do índice Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) avaliado pela curva Receiver Operating Characteristic (ROC) na detecção de síndrome metabólica em crianças pré-púberes com excesso de peso.

OBJECTIVE: To establish, among the cut-off values for the homeostatic model assessment for insulin resistance index (HOMA-IR) cited in the literature, the best in identifying metabolic syndrome (MS) in obese and overweight children. METHODS: A total of 106 pre-pubertal children were studied. The definition of MS was adapted from that of the International Diabetes Federation. For each cut-off values for HOMA-IR, it was estimated sensibility and specificity for MS. A receiver operating characteristic (ROC) curve was generated using these values. RESULTS: The study included 106 obese (37 girls and 69 boys) and 34 overweight (19 girls and 15 boys) children aged 6,5 +/- 2,3 years. The accuracy of the ROC curve was 72%, and the best cut-off value for HOMAIR was 2,5, with sensitivity of 61% and specificity of 74%. CONCLUSIONS: HOMA-IR may be useful to detect MS and the cut-off 2,5 seems to be the best in obese and overweight pre-pubertal children.