RESUMO
BACKGROUND: Childhood asthma is often characterized by recurrent wheezing, airway hyper-reactivity, atopy, and altered immune characteristics; however, our understanding of the development of these relationships from early in life remains unclear. The aim of our study was to evaluate whether atopy, cytokine production by peripheral blood mononuclear cells (PBMCs), and airway responsiveness, assessed in infants and toddlers, are associated with asthma and airway responsiveness at 4-years of age. METHODS: Infants with eczema (N = 116), enrolled prior to wheezing, were assessed at entry (mean age of 10.7 months), at 1-year follow-up (N = 112), and at 4-years of age (N = 94). Total serum IgE, specific IgE to allergens, and cytokines produced by stimulated PBMCs, were assessed at entry and 1-year follow-up. Spirometry was obtained at all 3-visits, while airway reactivity to methacholine was assessed at entry and 1-year follow-up, and bronchodilator (BD) responsiveness, as well as current asthma was assessed at 4-years of age. RESULTS: We found that pre-school children with asthma had lower spirometry and a greater BD-response. Serum IgE, particularly to egg and/or milk, and altered cytokine production by PBMCs at entry to the study were associated with asthma, lower spirometry, and greater airway responsiveness at 4-years of age. In addition, we found that airway responsiveness, as well as spirometry, tracked from infancy to 4-years of age. CONCLUSIONS: While spirometry and airway responsiveness track longitudinally from early in life, atopy and cytokine production by PBMCs are associated not only with an increased risk of pre-school asthma, but also lower spirometry and increased airway responsiveness.
Assuntos
Asma/fisiopatologia , Citocinas/sangue , Dermatite Atópica/complicações , Hipersensibilidade Alimentar/complicações , Imunoglobulina E/sangue , Sons Respiratórios , Asma/sangue , Asma/diagnóstico , Asma/etiologia , Biomarcadores/sangue , Testes de Provocação Brônquica , Pré-Escolar , Feminino , Seguimentos , Hipersensibilidade Alimentar/sangue , Hipersensibilidade Alimentar/diagnóstico , Humanos , Lactente , Modelos Logísticos , Masculino , Medição de Risco , Fatores de Risco , EspirometriaRESUMO
OBJECTIVE: To comparatively examine the effects of adiposity on the levels of plasma renin activity (PRA), plasma aldosterone concentration (PAC), and aldosterone-renin ratio (ARR) in young black and white children. STUDY DESIGN: We prospectively assessed 248 black and 345 white children and adolescents. A novel analytical technique was used to assess the concurrent influences of age and body mass index (BMI) on PRA, PAC, and ARR. The estimated effects were depicted by colored contour plots. RESULTS: In contrast to whites, blacks had lower PRA (2.76 vs 3.36 ng/mL/h; P < .001) and lower PAC (9.01 vs 14.59 ng/dL; P < .001). In blacks, BMI was negatively associated with PRA (P = .001), consistent with an association with a more expanded plasma volume; there was no association with PAC. In whites, BMI was positively associated with PAC (P = .005); we did not detect a BMI-PRA association. The effects of BMI on ARR were directionally similar in the two race groups but more pronounced in blacks. Mean systolic blood pressure was greater in blacks with lower PRA (P < .01), higher PAC (P = .015), and higher ARR (P = .49). CONCLUSIONS: An increase in adiposity was associated with a suppressed PRA in blacks and an increase in PAC in whites. The unique relationship between adiposity and renin-aldosterone axis in blacks suggests the possible existence of a population-specific mechanism characterized by volume expansion, which could in turn enhance the influences of adiposity on blood pressure in black children and adolescents.