Immune diseases such as asthma, allergy, inflammatory bowel disease, and type 1 diabetes have shown a parallel increase in prevalence during recent decades in westernized countries. The rate of ...cesarean delivery has also increased in this period and has been associated with the development of some of these diseases.
Mature children born by cesarean delivery were analyzed for risk of hospital contact for chronic immune diseases recorded in the Danish national registries in the 35-year period 1977-2012. Two million term children participated in the primary analysis. We studied childhood diseases with a suspected relation to a deviant immune-maturation and a debut at young age. The effect of cesarean delivery on childhood disease incidences were estimated by means of confounder-adjusted incidence rate ratios with 95% confidence intervals obtained in Poisson regression analyses.
Children delivered by cesarean delivery had significantly increased risk of asthma, systemic connective tissue disorders, juvenile arthritis, inflammatory bowel disease, immune deficiencies, and leukemia. No associations were found between cesarean delivery and type 1 diabetes, psoriasis, or celiac disease.
Cesarean delivery exemplifies a shared environmental risk factor in early life associating with several chronic immune diseases. Understanding commonalities in the underlying mechanisms behind chronic diseases may give novel insight into their origin and allow prevention.
Background Lower respiratory tract infections in the first years of life are associated with later asthma, and this observation has led to a focus on the potential causal role of specific respiratory ...viruses, such as rhinoviruses and respiratory syncytial virus, in asthma development. However, many respiratory viruses and bacteria trigger similar respiratory symptoms and it is possible that the important risk factors for asthma are the underlying susceptibility to infection and the exaggerated reaction to such triggers rather than the particular triggering agent. Objective We sought to study the association between specific infections in early life and development of asthma later in childhood. Methods Three hundred thirteen children were followed prospectively in the Copenhagen Prospective Studies of Asthma in Childhood2000 high-risk birth cohort. Nine respiratory virus types (respiratory syncytial virus, rhinoviruses, other picornaviruses, coronaviruses 229E and OC43, parainfluenza viruses 1-3, influenza viruses AH1, AH3, and B, human metapneumovirus, adenoviruses, and bocavirus) and 3 pathogenic airway bacteria ( Streptococcus pneumoniae , Haemophilus influenzae , and Moraxella catarrhalis ) were identified in airway secretions sampled during episodes of troublesome lung symptoms in the first 3 years of life. Asthma was determined by age 7 years. Results In unadjusted analyses, all viruses and pathogenic bacteria identified during episodes of troublesome lung symptoms were associated with increased risk of asthma by age 7 years with similar odds ratios for all viruses and pathogenic bacteria. After adjustment for the frequency of respiratory episodes, the particular triggers were no longer associated with asthma. Conclusion The number of respiratory episodes in the first years of life, but not the particular viral trigger, was associated with later asthma development. This suggests that future research should focus on the susceptibility and exaggerated response to lower respiratory tract infections in general rather than on the specific triggering agent.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Maternal use of antibiotics during pregnancy has been associated with the development of asthmatic disorders in the offspring. The human microbiome has been suggested to act as an intermediary in ...this process. To provide clarification on this theory, we studied the temporal relation between maternal use of antibiotics and the risk of childhood asthma.
According to national registries, during the observation period (1997-2010), 910,301 children were born in Denmark and were included in the analysis. From these registries, data for cases of childhood asthma were obtained based on hospital admissions, outpatient attendance at a hospital, or use of inhaled corticosteroids. The effect of timing of maternal antibiotic use on the risk of asthma in the offspring was studied by analysis of maternal antibiotic use in the 80 weeks before pregnancy, during pregnancy, and the 80 weeks after pregnancy. Results were adjusted for age and calendar year, birthweight, gestational age, sex, mode of delivery, parity, multiple births, season of birth, and several maternal factors (age, smoking during pregnancy, employment status, and asthma).
In this study, we replicated our previous finding that maternal use of antibiotics in pregnancy was associated with an increased risk of childhood asthma: the adjusted incidence rate ratio (aIRR) was 1·24 (95% CI 1·18-1·30) for inpatient admission, 1·22 (1·18-1·26) for outpatient attendance, and 1·18 (1·15-1·20) for inhaled corticosteroid use. A similar and independent association was also recorded for maternal antibiotic use in the 80 weeks before and after the pregnancy. A dose-related association occurred between the risk of childhood asthma and the number of maternal antibiotic treatments and was recorded separately for antibiotic treatment for respiratory tract infections and for other types of infections.
Maternal use of antibiotics has a dose-related association with the risk of asthma in the offspring, but this association is independent of the temporal relationship with the pregnancy period. This finding suggests that maternal antibiotic use is a surrogate marker of a mother's general propensity for infections as the underlying link between a mother's use of antibiotics and risk of asthma in the offspring.
The Danish Council for Strategic Research, The Lundbeck Foundation, The Pharmacy Foundation of 1991, the Danish Medical Research Council, and National Finance Act.
Chronic immune diseases are often reported to be on the rise and are speculated to share early life risk factors. Here, we investigated year of birth as a common denominator for time trends using the ...consistent data source of the Danish National Patient Registry with 35 years nationwide coverage. Observational nationwide birth cohort registry study, where persons born in Denmark since 1953 were investigated for chronic immune diseases per person years at risk. Outcomes were defined by inpatient hospitalizations in pre-chosen age bins by year of birth in 5 year bins. A population of 3.8 million persons born in Denmark since 1953 was investigated for a total sum of 68 million person years in the ages 5–34 years. We found increasing trends by year of birth for juvenile arthritis age 10–14, adult asthma age 20–24, inflammatory bowel diseases age 20–24, and multiple sclerosis age 25–29, whereas type 1 diabetes age 15–19 was declining until birth year mid 1980s followed by a subsequent increase. Childhood asthma age 5–9 inpatient hospitalizations were relatively stable over time. Nationwide introduction of measles, mumps, rubella vaccine in 1987 did not alter the trends. Hospitalization for the chronic immune diseases adult asthma, juvenile arthritis, inflammatory bowel diseases and multiple sclerosis showed a general increasing trend by birth year in recent 35 years while diabetes 1 and childhood asthma seemed stable in this period. These results were not affected by the introduction of vaccinations against the major childhood viral infections.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Objective To assess our prospective mother-child cohort and the national registry data to analyze the risk of asthma by delivery mode and whether cesarean delivery before or after membrane rupture ...affects this risk differently. Study design The Copenhagen Prospective Studies on Asthma in Childhood2000 is a high-risk birth cohort of 411 Danish children. Asthma was diagnosed prospectively by physicians at the research site, and associations with cesarean delivery were investigated using Cox proportional hazard models. From the Danish national prospective registry we included data from 1997-2010. Childhood asthma was defined from recurrent use of inhaled corticosteroids filled at pharmacies. Cesarean delivery was classified as either before or after rupture of membranes, and the risk of asthma was compared with vaginal delivery. Results were adjusted stepwise for age and calendar year, sex, birth weight, gestational age, multiple births, parity, and maternal factors (age, smoking/antibiotics during pregnancy, employment status, and asthma). Results In the Copenhagen Prospective Studies on Asthma in Childhood2000 cohort, the adjusted hazard ratio for asthma was increased by cesarean delivery relative to vaginal birth 2.18 (1.27-3.73). Registry data replicated these findings. Cesarean delivery performed before rupture of membranes carried significantly higher risk of asthma, (incidence rate ratio to vaginal delivery 1.20 1.16-1.23) than cesarean delivery after rupture of membranes (incidence rate ratio to vaginal delivery 1.12 1.09-1.16). Conclusions We confirmed cesarean delivery to be a risk factor for childhood asthma. This effect was more pronounced for cesarean delivery performed before rupture of membranes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Rationale: Infants and young children might be particularly likely to experience the potential clinical side effects of inhaled corticosteroids (ICSs) on body mass index (BMI), adiposity rebound ...(AR), and body composition, but this has rarely been studied in long-term studies in this age group. Objectives: To determine the association between ICS exposure in the first 6 years of life and the BMI, AR, body composition, and blood lipid concentrations. Methods: Children from the two mother-child cohorts of the COPSAC (Copenhagen Prospective Studies on Asthma in Childhood) were included. ICS use was registered prospectively to age 6 years, and the cumulative dose was calculated. Multiple linear regression models were used for analysis. Measurements and Main Results: A total of 932 (84%) of the 1,111 children from the COPSAC cohorts had BMI data, 786 (71%) had dual-energy X-ray absorptiometry scan data at the age of 6 years, and 815 (73%) had an AR age calculated. Two hundred ninety-one children (31%) received a cumulative ICS dose higher than that from 10 weeks of standard treatment before the age of 6. ICS treatment during 0-6 years of age was associated with an increased BMI z-score (0.05 95% confidence interval, 0.005 to 0.09 SDs per each year of standard treatment; P = 0.03) an earlier age at AR (-0.18 95% confidence interval, -0.28 to -0.08 yr; P = 0.0006), and a 2% increased geometric mean android fat percentage (P = 0.05). ICS exposure and dual-energy X-ray absorptiometry scan data were not associated. Conclusions: ICS use in early childhood was associated with an increased BMI z-score at age 6, an earlier AR, and a trend of association with an increased android body fat percentage.
Asthma and autoimmune disorders might be affected by opposing immune mechanisms, T helper cells type 2 (Th2) and T helper cells type 1 (Th1) immunity, respectively. Knowledge on comorbidity can ...increase understanding of the underlying etiologies. We aim to examine the association between childhood asthma and subsequent risk of type 1 diabetes (T1D) and inflammatory bowel diseases (IBD) in Danish children. Children of Danish origin born during 1991-1996 were included and childhood asthma, defined as a minimum of two collected prescriptions of inhalation corticosteroids age 5-7 years, was linked to hospitalisations with either T1D or IBD after age 8. Associations between childhood asthma and incidence of T1D and IBD were analysed using sex- and year stratified Cox regression. A total of 366,200 children were included in the study, 4.9% had asthma, which increased the risk of both T1D and IBD, hazard ratios of 1.32 (1.08-1.61) and 1.27 (1.09-1.48). In this large nationwide Danish study, we found that children with asthma have increased risk of developing immune diseases T1D and IBD. This contradicts the Th1 vs Th2 paradigm and points towards shared disease mechanisms and risk factors.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Background Wheezy episodes in young children are often triggered by viral and bacterial respiratory tract infections, but there is little evidence supporting the hypothesis that symptom duration ...depends on the specific microbial trigger. Objective We sought to investigate whether the duration of wheezy episodes in young children depends on the microbial trigger. Methods Two hundred eighty-three children from the Copenhagen Prospective Study on Asthma in Childhood2000 at-risk birth cohort were prospectively examined for common airway pathogenic bacteria and viruses during acute wheezy episodes in the first 3 years of life. Findings were related to symptomatic duration of episodes, as monitored in daily diary cards from birth. Results Eight hundred thirty-seven samples were investigated for viruses, bacteria, or both. Both viruses and bacteria were identified in 55% of episodes, bacteria were identified exclusively in 31% of episodes, and viruses were identified exclusively in 10% of episodes. The median duration of acute symptoms was 9 days (interquartile range, 5-16 days), and duration was independent of bacterial or viral species. Conclusions The duration of wheezy episodes was independent of pathogenic airway bacterial or viral species. This suggests that symptom burden from infections is dependent on other factors, such as environmental exposures or host factors. The common term viral wheeze seems inappropriate in view of the finding of pathogenic bacteria in 86% of wheezy episodes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Randomized trials have reported that supplementation with n–3 long-chain polyunsaturated fatty acids (LCPUFAs) in pregnancy can prolong pregnancy and thereby increase birth weight.
We aimed to ...examine the relations of n–3 LCPUFA supplementation in pregnancy with duration of pregnancy, birth weight, and size for gestational age (GA).
This was a double-blind randomized controlled trial conducted in 736 pregnant women and their offspring, from the Copenhagen Prospective Studies on Asthma in Childhood2010cohort. They were recruited between weeks 22 and 26 in pregnancy and randomly assigned to either of 2.4 g n–3 LCPUFA or control (olive oil) daily until 1 wk after birth. Exclusion criteria were endocrine, cardiovascular, or nephrologic disorders and vitamin D supplementation intake >600 IU/d. In this study we analyzed secondary outcomes, and further excluded twin pregnancies and extrauterine death. The primary outcome for the trial was persistent wheeze or asthma.
The random assignment ran between 2008 and 2010. Six hundred and ninety-nine mother-infant pairs were included in the analysis. n–3 LCPUFA compared with control was associated with a 2-d prolongation of pregnancy median (IQR): 282 (275–288) d compared with 280 (273–286) d, P = 0.02, a 97-g higher birth weight (mean ± SD: 3601 ± 534 g compared with 3504 ± 528 g, P = 0.02), and an increased size for GA according to the Norwegian population-based growth curves-Skjærven (mean ± SD: 49.9 ± 28.3 percentiles compared with 44.5 ± 27.6 percentiles, P = 0.01).
Supplementing pregnant women with n–3 LCPUFAs during the third trimester is associated with prolonged gestation and increased size for GA, leading to a higher birth weight in this randomized controlled trial. This trial was registered at clinicaltrials.gov as NCT00798226.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Childhood asthma is consistently reported to have increased in recent decades in most westernized countries, but it is unknown if this increase is similar across severities. We aimed to study the ...time-trend of acute hospital admission and readmission for asthma of schoolaged children in the recent 35 years in Denmark. We analyzed time-trends in the national incidence rate of hospitalization for acute severe asthma in children aged 5-15 in Denmark during the 35-year period 1977-2012 in the Danish national registry. Only in-patient admissions with a principal diagnosis of asthma (ICD-8: 493** or ICD-10: J45** or J46**) were included. Among children with asthma hospitalizations, we investigated the risk of readmission beyond 1 month of first admission. Admissions were summarized as rates per thousand person years at risk. The overall time-trend is stable with a rate of one admission per year per thousand children at risk and a peryear incidence rate ratio 0.999 95 % CI 0.997-1.001. The rate of any readmission decreased from approximately 20 per thousand children in the eighties to less than 10 in the early nineties before stabilizing at around 10 per thousand children from mid-nineties and onwards. During 35 years of nation-wide follow-up, we find a highly stable incidence rate of first hospital admission for acute severe asthma in children. Moreover, rates of readmission halved during the seventies and stabilized in the last twenty years. In conclusion, our data suggest that the reported increase in childhood asthma is mainly due to less severe cases.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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