RESUMEN
BACKGROUND: Allergic sensitization is associated with eczema, asthma, and rhinitis. However, it is unknown whether and how allergic sensitization is associated over time with acquisition, remission, and persistence of these diseases and their comorbidity. OBJECTIVE: To gain a better understanding of factors including allergic sensitization transitions that influence the temporal pattern of asthma, eczema, and rhinitis and their comorbidity during childhood. METHODS: In the Isle of Wight birth cohort, information on allergic sensitization to common allergens was collected at ages 4, 10, and 18 years along with asthma, rhinitis, and eczema status determined by clinical diagnosis. Logistic regressions were used to estimate subsequent and concurrent odds ratios of diseases transition with allergic sensitization transition status as the main independent variable. Two transition periods were considered, 4 to 10 years of age and 10 to 18 years of age. RESULTS: The odds of new diagnosis of allergic disease (no-yes) was increased among subjects with acquired or persistent allergic sensitization to common allergens compared to subjects with no sensitization (acquisition of sensitization odds ratio [OR]=3.22, P < .0001; persistence of sensitization, OR=6.33, P < .0001). The odds of remission of allergic diseases (yes-no) was lower among subjects with acquired or sustained allergic sensitization (acquisition, OR=0.18, P = .0001; persistence, OR=0.085, P < .0001), compared to subjects not sensitized. Subjects with acquired or persistent allergic sensitization were also had higher odds for persistence of disease (yes-yes) than subjects not sensitized (acquisition, OR=5.49, P = .0001; persistence, OR=11.79, P < .0001). CONCLUSION: Transition of allergic sensitizations to common allergens is a prognostic factor for subsequent or concurrent transition of eczema, asthma, and rhinitis. Prevention or reduction in allergic sensitization has a potential to lead to remission of these conditions.
Asunto(s)
Asma/epidemiología , Eccema/epidemiología , Hipersensibilidad/epidemiología , Rinitis/epidemiología , Adolescente , Asma/etiología , Niño , Preescolar , Comorbilidad , Eccema/etiología , Inglaterra/epidemiología , Femenino , Humanos , Hipersensibilidad/complicaciones , Estudios Longitudinales , Masculino , Rinitis/etiologíaRESUMEN
BACKGROUND: Modes of infant feeding such as direct and indirect breastfeeding, and formula feeding, and their combinations may play a role in child health. OBJECTIVE: The aim was to investigate which feeding patterns in the first 6 months pose risks of eczema/skin allergy in children up to 6 years compared to direct breastfeeding for at least 3 months. METHODS: The Infant Feeding Practices Study II in the United States and its 6-year follow-up provided data on feeding modes in infancy and doctor's diagnosed eczema/skin allergy in the first 6 years of life (1387 infants), based on parental reports. Different feeding patterns were identified. Log-linear models were used to estimate prevalence ratios (PRs) of feeding patterns for doctor's diagnosed eczema/skin allergy in the first 6 years of life, adjusting for confounders. RESULTS: Compared to "direct breastfeeding for at least 3 months" (DBF3m), the combination of "direct feeding at the breast (DBF), pumping and feeding breast milk (BM), and formula (FF) in the first months" (DBF/BM/FF) showed a statistically significant higher risk of eczema/skin allergy in the first 6 years of life (PR = 1.46), adjusting for confounders. DBF combined with BM for the first 3 months followed by mixed feeding also had an increased risk (PR = 1.26), although not statistically significant. Formula feeding introduced since birth had no effect on eczema. Among the confounders, paternal eczema and race/ethnicity (Hispanic vs White) were associated with a higher risk of eczema/skin allergy. CONCLUSIONS & CLINICAL RELEVANCE: Mixed infant feeding may carry a higher risk of eczema/skin allergy compared to direct feeding at the breast. The recent epidemic of pumping and feeding in the United States and the use of mixed infant feeding modes requires additional studies to provide appropriate and renewed assessments of the risks of feeding modes for the future development of allergies.
Asunto(s)
Eccema/epidemiología , Eccema/etiología , Conducta Alimentaria , Factores de Edad , Niño , Preescolar , Femenino , Encuestas Epidemiológicas , Humanos , Lactante , Recién Nacido , Masculino , Prevalencia , Factores de RiesgoRESUMEN
BACKGROUND: Season of birth influences allergy risk; however, the biological mechanisms underlying this observation are unclear. The environment affects DNA methylation, with potentially long-lasting effects on gene expression and disease. This study examined whether DNA methylation could underlie the association between season of birth and allergy. METHODS: In a subset of 18-year-old participants from the Isle of Wight (IoW) birth cohort (n = 367), the risks of birth season on allergic outcomes were estimated. Whole blood epigenome-wide DNA methylation was measured, and season-associated CpGs detected using a training-and-testing-based technique. Validation method examined the 8-year-old Prevention and Incidence of Asthma and Mite Allergy (PIAMA) cohort. The relationships between DNA methylation, season of birth and allergy were examined. CpGs were analysed in IoW third-generation cohort newborns. RESULTS: Autumn birth increased risk of eczema, relative to spring birth. Methylation at 92 CpGs showed association with season of birth in the epigenome-wide association study. In validation, significantly more CpGs had the same directionality than expected by chance, and four were statistically significant. Season-associated methylation was enriched among networks relating to development, the cell cycle and apoptosis. Twenty CpGs were nominally associated with allergic outcomes. Two CpGs were marginally on the causal pathway to allergy. Season-associated methylation was largely absent in newborns, suggesting it arises post-natally. CONCLUSIONS: This study demonstrates that DNA methylation in adulthood is associated with season of birth, supporting the hypothesis that DNA methylation could mechanistically underlie the effect of season of birth on allergy, although other mechanisms are also likely to be involved.
Asunto(s)
Metilación de ADN , Hipersensibilidad/epidemiología , Hipersensibilidad/etiología , Estaciones del Año , Adolescente , Niño , Preescolar , Islas de CpG , Susceptibilidad a Enfermedades , Femenino , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Lactante , Recién Nacido , Masculino , Exposición Materna , Embarazo , Efectos Tardíos de la Exposición Prenatal , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: WHO guidelines advocate breastfeeding for 6 months, and EAACI guideline recommends exclusive breastfeeding for 4-6 months. However, evidence for breastfeeding to prevent asthma and allergic disease is conflicting. We examined whether following recommended breastfeeding guidelines alters the long-term risks of asthma, eczema, rhinitis or atopy. METHODS: The effect of nonexclusive (0, >0-6, >6 months) and exclusive breastfeeding (0, >0-4, >4 months) on repeated measures of asthma (10, 18 years), eczema, rhinitis, and atopy (1-or-2, 4, 10, 18 years) risks was estimated in the IoW cohort (n = 1456) using log-linear models with generalized estimating equations. The Food Allergy and Intolerance Research (FAIR) cohort (n = 988), also from the IoW, was examined to replicate results. RESULTS: Breastfeeding (any or exclusive) had no effect on asthma and allergic disease in the IoW cohort. In the FAIR cohort, any breastfeeding for >0-6 months protected against asthma at 10 years (RR = 0.50, 95% CI = 0.32-0.79, P = 0.003), but not other outcomes, whilst exclusive breastfeeding for >4 months protected against repeated rhinitis (RR = 0.36, 95% CI = 0.18-0.71, P = 0.003). Longer breastfeeding was protective against late-onset wheeze in the IoW cohort. CONCLUSION: The protective effects of nonexclusive and exclusive breastfeeding against long-term allergic outcomes were inconsistent between these colocated cohorts, agreeing with previous observations of heterogeneous effects. Although breastfeeding should be recommended for other health benefits, following breastfeeding guidelines did not appear to afford a consistent protection against long-term asthma, eczema, rhinitis or atopy. Further research is needed into the long-term effects of breastfeeding on allergic disease.
Asunto(s)
Lactancia Materna , Hipersensibilidad/etiología , Hipersensibilidad/prevención & control , Adolescente , Niño , Preescolar , Estudios de Cohortes , Femenino , Guías como Asunto , Humanos , Hipersensibilidad/diagnóstico , Hipersensibilidad/epidemiología , Lactante , Masculino , Exposición Materna , Evaluación de Resultado en la Atención de Salud , Embarazo , Ruidos Respiratorios/etiología , Riesgo , Factores Socioeconómicos , Factores de TiempoRESUMEN
Breastfeeding has been linked with increased forced vital capacity (FVC) in children but not in older adolescents. Our aim was to investigate the effects of breastfeeding duration and infant weight gain on FVC in both developmental periods. In a birth cohort, information on breastfeeding duration was collected at 1 and 2 yrs; spirometric tests were conducted at 10 and 18 yrs. To estimate the effect of breastfeeding duration on FVC at 18 yrs of age, we used linear models; to analyse repeated FVC measurements at 10 and 18 yrs of age, we used linear mixed models. Links between breastfeeding, infant weight gain and FVC at 10 and 18 yrs of age were analysed through path analyses. Among 808 breastfed children, 49% were breastfed for ≥ 4 months. At 18 yrs of age the augmenting effect of breastfeeding on FVC was reduced with increased height. Linear mixed models identified that breastfeeding duration was associated with increased FVC. Path analysis suggested a direct effect of breastfeeding on FVC at 10 yrs of age, but an indirect effect at 18 yrs of age via FVC at 10 yrs of age. Although inversely related to breastfeeding, a higher weight gain in infants led to taller adolescents and, in turn, resulted in increased FVC. In conclusion, a longer duration of breastfeeding contributes to lung health in childhood and adolescence.