A meta-analysis of the association between childhood type 1 diabetes and atopic disease

No associations between type 1 diabetes and atopic dermatitis, allergic rhinitis, or asthma in childhood: a nationwide Danish case-cohort study

Studies examining the association between type 1 diabetes (T1D) and atopic diseases, i.e., atopic dermatitis, allergic rhinitis and asthma have yielded conflicting results due to different algorithms for classification, sample size issues and risk of referral bias of exposed cohorts with frequent contact to health care professionals. Using Danish national registries and well-established disease algorithms, we examined the bidirectional association between T1D and atopic diseases in childhood and adolescence using Cox Proportional Hazard regression compared to two different unexposed cohorts from a population of 1.5 million Danish children born from 1997 to 2018. We found no associations between T1D and atopic dermatitis, allergic rhinitis, or asthma (defined after age five). However, in multivariable analysis we found an increased risk of persistent wheezing (defined as asthma medication before age five) after T1D with an adjusted hazard ratio (aHR) of 1.70 [1.17-2.45]. We also identified an increased risk of developing T1D after persistent wheezing with aHR of 1.24 [1.13-1.36]. This study highlights similar risks of atopic diseases in children with T1D and of T1D in children with atopic disease after age of five years versus healthy controls. However, more research is needed to understand the possible early immunological effects of the link between persistent wheezing and T1D.

Environmental Risk Factors, Protective Factors, and Biomarkers for Allergic Rhinitis: A Systematic Umbrella Review of the Evidence

Many potential environmental risk factors, protective factors, and biomarkers of AR have been published, but so far, the strength and consistency of their evidence are unclear. We conducted a comprehensive review of environmental risk, protective factors, and biomarkers for AR to establish the evidence hierarchy. We systematically searched Embase, PubMed, Cochrane Library, and Web of Science electronic database from inception to December 31, 2022. We calculated summary effect estimate (odds ratio (OR), relative risk (RR), hazard ratio (HR), and standardized mean difference (SMD)), 95% confidence interval, random effects p value, I2 statistic, 95% prediction interval, small study effects, and excess significance biases, and stratification of the level of evidence. Methodological quality was assessed by AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews 2). We retrieved 4478 articles, of which 43 met the inclusion criteria. The 43 eligible articles identified 31 potential environmental risk factors (10,806,206 total population, two study not reported), 11 potential environmental protective factors (823,883 total population), and 34 potential biomarkers (158,716 total population) for meta-analyses. The credibility of evidence was convincing (class I) for tic disorders (OR = 2.89, 95% CI 2.11-3.95); and highly suggestive (class II) for early-life antibiotic use (OR = 3.73, 95% CI 3.06-4.55), exposure to indoor dampness (OR = 1.49, 95% CI 1.27-1.75), acetaminophen exposure (OR = 1.54, 95% CI 1.41-1.69), childhood acid suppressant use (OR = 1.40, 95% CI 1.23-1.59), exposure to indoor mold (OR = 1.66, 95% CI 1.26-2.18), coronavirus disease 2019 (OR = 0.11, 95% CI 0.06-0.22), and prolonged breastfeeding (OR = 0.72, 95% CI 0.65-0.79). This study is registered in PROSPERO (CRD42022384320).

The Association Between Insulin Use and Asthma: An Epidemiological Observational Analysis and Mendelian Randomization Study

BACKGROUND

Asthma is a common respiratory disease caused by genetic and environmental factors, but the contribution of insulin use to the risk of asthma remains unclear. This study aimed to investigate the association between insulin use and asthma in a large population-based cohort, and further explore their causal relationship by Mendelian randomization (MR) analysis.

METHODS

An epidemiological study including 85,887 participants from the National Health and Nutrition Examination Survey (NHANES) 2001-2018 was performed to evaluate the association between insulin use and asthma. Based on the inverse-variance weighted approach, MR analysis were conducted to estimate the causal effect of insulin use on asthma from the UKB and FinnGen datasets, respectively.

RESULTS

In the NHANES cohort, we found that insulin use was associated with an increased risk of asthma [odd ratio (OR) 1.38; 95% CI 1.16-1.64; p < 0.001]. For the MR analysis, we found a causal relationship between insulin use and a higher risk of asthma in both Finn (OR 1.10; p < 0.001) and UK Biobank cohorts (OR 1.18; p < 0.001). Meanwhile, there was no causal association between diabetes and asthma. After multivariable adjustment for diabetes in UKB cohort, the insulin use remained significantly associated with an increased risk of asthma (OR 1.17, p < 0.001).

CONCLUSIONS

An association between insulin use and an increased risk of asthma was found via the real-world data from the NHANES. In addition, the current study identified a causal effect and provided a genetic evidence of insulin use and asthma. More studies are needed to elucidate the mechanisms underlying the association between insulin use and asthma.

Is Atopic Dermatitis Only a Skin Disease?

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory dermatosis that imposes significant patient and population burdens. In addition to the cutaneous signs and symptoms, growing evidence suggests that AD is systemic in nature. Certain diseases can possibly co-occur with AD as a result of coincidental exposure to similar environmental factors. However, it is also suspected that they are linked to the pathogenesis of AD through more complex genetic and immunological mechanisms, but these correlations remain less understood. It is of great need to seek explanations for the higher frequency of the number of cardiovascular, autoimmune, neurological, psychiatric, and metabolic disorders that have been observed in epidemiologic investigations among AD patients. Moreover, analysing the immunology of chronic inflammation and its correction, activation, or suppression may prevent the development of a variety of comorbidities. As comorbid diseases in patients diagnosed with AD may potentially go undetected, physicians should be aware of them.

Childhood asthma and type 1 diabetes mellitus: A meta-analysis and bidirectional Mendelian randomization study

BACKGROUND

Worldwide incidence and prevalence of both asthma and type 1 diabetes mellitus (T1DM) in children have been increasing in past decades. Association between the two diseases has been found in some but not in other studies.

OBJECTIVE

We conducted a meta-analysis to verify such an association, and bidirectional Mendelian randomization analysis to examine the potential cause-effect relationships.

METHODS

Three databases (PubMed, Embase, and Web of Science) were searched from their inception to February 1, 2021. Pooled hazard ratios (HR) or odds ratios (OR), and 95% confidence intervals, were calculated. Associations between single-nucleotide polymorphisms with childhood asthma and T1DM were selected based on genome-wide association studies. The outcome datasets were obtained from FinnGen study. We used the inverse-variance-weighted (IVW), weighted median and MR-Egger methods to estimate causal effects. To assess robustness and horizontal pleiotropy, MR-Egger regression and MR pleiotropy residual sum and outlier test were conducted.

RESULTS

In meta-analysis, childhood asthma was associated with an increased risk of T1DM (HR = 1.30, 95% CI 1.05-1.61, P = .014), whereas T1DM was not associated with the risk of asthma (HR = 0.98, 95% CI 0.64-1.51, P = .941; OR = 0.84, 95% CI 0.65-1.08, P = .168). MR analysis indicated increased genetic risk of T1DM in children with asthma (OR = 1.308; 95% CI 1.030-1.661; P = .028). Analysis using the IVW method indicated no association between T1DM and genetic risk of asthma (OR = 1.027, 95%CI 0.970-1.089, P = .358).

CONCLUSION

Both meta-analysis and MR study suggested that childhood asthma was a risk factor for T1DM. No epidemiological or genetic evidence was found for an association of T1DM with asthma incidence. Further studies could be carried out to leverage this newfound insight into better clinical and experimental research in asthma and T1DM.

Paediatric asthma and non-allergic comorbidities: A review of current risk and proposed mechanisms

It is increasingly recognized that children with asthma are at a higher risk of other non-allergic concurrent diseases than the non-asthma population. A plethora of recent research has reported on these comorbidities and progress has been made in understanding the mechanisms for comorbidity. The goal of this review was to assess the most recent evidence (2016-2021) on the extent of common comorbidities (obesity, depression and anxiety, neurodevelopmental disorders, sleep disorders and autoimmune diseases) and the latest mechanistic research, highlighting knowledge gaps requiring further investigation. We found that the majority of recent studies from around the world demonstrate that children with asthma are at an increased risk of having at least one of the studied comorbidities. A range of potential mechanisms were identified including common early life risk factors, common genetic factors, causal relationships, asthma medication and embryologic origins. Studies varied in their selection of population, asthma definition and outcome definitions. Next, steps in future studies should include using objective measures of asthma, such as lung function and immunological data, as well as investigating asthma phenotypes and endotypes. Larger complex genetic analyses are needed, including genome-wide association studies, gene expression-functional as well as pathway analyses or Mendelian randomization techniques; and identification of gene-environment interactions, such as epi-genetic studies or twin analyses, including omics and early life exposure data. Importantly, research should have relevance to clinical and public health translation including clinical practice, asthma management guidelines and intervention studies aimed at reducing comorbidities.

Hormonal Effects on Asthma, Rhinitis, and Eczema

Hormones significantly influence the pathogenesis of asthma, rhinitis, and eczema. This review aims to summarize relevant clinical considerations for practicing allergists and immunologists. The first section reviews the effects of sex hormones: estrogen, progesterone, and testosterone. The second concerns insulin production in the context of type 1 and type 2 diabetes. The third concludes with a discussion of thyroid and adrenal pathology in relationship to asthma, rhinitis, and eczema.

Epidemiologic Implication of the Association between Herpes Simplex Virus Infection and the Risk of Type 1 Diabetes Mellitus: A Nationwide Case-Control Study in Taiwan

Enterovirus infection is a known risk factor for type 1 diabetes (T1DM). Whether infection with other viruses induces T1DM remains undetermined. This study investigated the association between human herpesvirus (HHV) infection and the development of T1DM, using the data from Taiwan’s National Health Insurance Research Database. Patients with T1DM and age- and sex-matched controls were included. Subjects with HHV infection were subgrouped into those with histories of varicella-zoster virus, herpes simplex virus (HSV), Epstein-Barr virus, and human cytomegalovirus infections. The odds ratio of the risk of T1DM was calculated using a multivariable conditional logistic regression model. Atopic diseases, autoimmune thyroid diseases, and history of enterovirus infection served as adjusted comorbidities. Our findings suggested a significant association between HSV infection and the risk of T1DM (adjusted odds ratio: 1.21; 95% CI: 1.01–1.47, p = 0.048), while infection with other HHVs was not. The result of HSV infection remained significant when subjects were restricted to age ≤ 18 years (adjusted odds ratio: 1.35; 95% CI: 1.08–1.70, p = 0.010). We found a history of HSV infection might be an independent predictive risk factor for T1DM. This could be potentially helpful to the practice in public health.

Diabetes, insulin resistance, and asthma: a review of potential links

PURPOSE OF REVIEW

Disorders of glucose metabolism, including insulin resistance, prediabetes, and diabetes, have been identified as risk factors for worsened asthma. This review summarizes emerging evidence for their role as modifiable risk factors in asthma, including the potential benefit of diabetes medications on asthma outcomes.

RECENT FINDINGS

Experimental studies show that hyperinsulinemia associated with insulin resistance is associated with airway smooth muscle proliferation and promotes contractility. Epidemiologic studies have identified a higher prevalence of glycemic dysfunction among those with severe and uncontrolled asthma, and longitudinal studies have associated prediabetes and diabetes with higher risk of asthma exacerbations. The potential benefits of thiazolidinediones (TZDs), glucagon-like peptide-1 agonists, and metformin being investigated in asthma, but thus far interventional studies of TZDs have reported null results. On the contrary, observational studies have inconsistently controlled for relevant confounders which leaves conclusions vulnerable to misattribution of relationships due to corelated metabolic disorders, including dyslipidemia.

SUMMARY

Developing evidence suggests that disorders of glucose metabolism may be associated with worsening asthma. However, these conditions arise within a network of obesity-related metabolic diseases that may themselves worsen asthma. Few interventional trials have not identified a benefit, but data have been limited. Additional research is needed to define the potential independent impact of disorders of glucose metabolism in asthma.

Coaggregation of Asthma and Type 1 Diabetes in Children: A Narrative Review

Asthma and type 1 diabetes mellitus (T1DM) are two of the most frequent chronic diseases in children, representing a model of the atopic and autoimmune diseases respectively. These two groups of disorders are mediated by different immunological pathways, T helper (Th)1 for diabetes and Th2 for asthma. For many years, these two groups were thought to be mutually exclusive according to the Th1/Th2 paradigm. In children, the incidence of both diseases is steadily increasing worldwide. In this narrative review, we report the evidence of the potential link between asthma and T1DM in childhood. We discuss which molecular mechanisms could be involved in the link between asthma and T1DM, such as genetic predisposition, cytokine patterns, and environmental influences. Cytokine profile of children with asthma and T1DM shows an activation of both Th1 and Th2 pathways, suggesting a complex genetic-epigenetic interaction. In conclusion, in children, the potential link between asthma and T1DM needs further investigation to improve the diagnostic and therapeutic approach to these patients. The aim of this review is to invite the pediatricians to consider the potential copresence of these two disorders in clinical practice.

Cow's milk allergy in infancy and later development of type 1 diabetes-nationwide case-cohort study

BAKGROUND

It is suggested that early intake of cow's milk could be a risk factor for type 1 diabetes (T1DM). Further, the different immunological background, gives a suggestion of an inverse relationship for the occurrence of these diseases. The aim of this study was to explore the association between cow's milk allergy (CMA) and the risk of T1DM in a register-based case-cohort study.

METHODS

Data were obtained from Finnish nationwide health registers. The study included all children born in Finland between January 01, 1986 and December 31, 2008 and diagnosed with T1DM before the age of 16 years (n = 7754). A 10% random sample from each birth year cohort was selected as a reference cohort (n = 137,798). T1DM, CMA, and asthma were defined based on valid special reimbursements for the costs of drugs/special formulas needed in the treatment of the diseases. Child's sex, birth decade, asthma, maternal diabetes and asthma, smoking during pregnancy, and previous deliveries were considered as confounding factors. Time-dependent, weighted Cox regression was applied for statistical analyses.

RESULTS

Children with CMA had an increased risk of developing T1DM in fully adjusted model (HR = 1.17; 95% CI 1.02-1.34), but the association was no longer observed when including the use of special infant formulas in the definition of CMA in the sensitivity analysis (HR = 1.11; 95% CI 0.92-1.32). CMA was associated with an increased risk of T1DM in children without asthma (HR = 1.27; 95%CI 1.10-1.47), but not in children with asthma (HR = 0.80; 95% CI 0.92-1.27).

CONCLUSION

Children with CMA may have an increased risk of T1DM.

The Diabetic Lung: Insights into Pulmonary Changes in Children and Adolescents with Type 1 Diabetes

Historically, the lung was not listed and recognized as a major target organ of diabetic injury. The first evidence of diabetic lung involvement was published fifty years ago, with a study conducted in a population of young adults affected by type 1 diabetes (T1D). In recent years, there has been mounting evidence showing that the lung is a target organ of diabetic injury since the beginning of the disease—at the pediatric age. The deeply branched vascularization of the lungs and the abundance of connective tissue, indeed, make them vulnerable to the effects of hyperglycemia, in a way similar to other organs affected by microvascular complications. In this review, we focus on pulmonary function impairment in children and adolescents affected by T1D. We also cover controversial aspects regarding available studies and future perspectives in this field.

Why is the Incidence of Type 1 Diabetes Increasing?

Type 1 diabetes is a condition that can lead to serious long-term complications and can have significant psychological and quality of life implications. Its incidence is increasing in all parts of the world, but the reasons for this are incompletely understood. Genetic factors alone cannot explain such a rapid increase in incidence; therefore, environmental factors must be implicated. Lifestyle factors have been classically associated with type 2 diabetes. However, there are data implicating obesity and insulin resistance to type 1 diabetes as well (accelerator hypothesis). Cholesterol has also been shown to be correlated with the incidence of type 1 diabetes; this may be mediated by immunomodulatory effects of cholesterol. There is considerable interest in early life factors, including maternal diet, mode of delivery, infant feeding, childhood diet, microbial exposure (hygiene hypothesis), and use of anti-microbials in early childhood. Distance from the sea has recently been shown to be negatively correlated with the incidence of type 1 diabetes. This may contribute to the increasing incidence of type 1 diabetes since people are increasingly living closer to the sea. Postulated mediating mechanisms include hours of sunshine (and possibly vitamin D levels), mean temperature, dietary habits, and pollution. Ozone, polychlorinated biphenyls, phthalates, trichloroethylene, dioxin, heavy metals, bisphenol, nitrates/nitrites, and mercury are amongst the chemicals which may increase the risk of type 1 diabetes. Another area of research concerns the role of the skin and gut microbiome. The microbiome is affected by many of the factors mentioned above, including the mode of delivery, infant feeding, exposure to microbes, antibiotic use, and dietary habits. Research on the reasons why the incidence of type 1 diabetes is increasing not only sheds light on its pathogenesis but also offers insights into ways we can prevent type 1 diabetes.

Decreased frequency of allergy in juvenile idiopathic arthritis: Results of a case-control study

OBJECTIVES

To determine the frequency of Th2-mediated allergic diseases (AD) in mainly Th1-driven juvenile idiopathic arthritis (JIA) subtypes.

METHODS

Ninety-nine JIA patients and 128 control subjects were enrolled in a prospective case-control study. All subjects were assessed with standard allergy questionnaire, complete blood cell count, and total serum immunoglobulin (sIg) E. sIgs G, A, M, Juvenile Arthritis Disease Activity Score-27 (JADAS27), and serum acute phase reactants (sAPR) were obtained in JIA. In the presence of allergic symptoms, skin prick (SPT) and pulmonary function tests (PFT) were performed.

RESULTS

Despite similar allergy risk factors, the frequencies of asthma and allergic rhinitis were lower in JIA group (all p ≤ .02). Allergic patients with JIA performed lower FEV₁/FVC ratio, PEF, and FEF25-75 compared to the control group (all p ≤ .04). JADAS27 and sAPR were similar among JIA patients with and without AD. Two JIA patients were found to have hypogammaglobulinemia.

CONCLUSION

The frequencies of AD, asthma, and allergic rhinitis may decrease in Th1-mediated JIA subtypes although the coexistence does not appear to affect the severity of arthritis whereas allergic symptoms may resolve after immunosuppressive treatment. PFTs should be obtained periodically in JIA. JIA patients may have an underlying primary immunodeficiency (ID) or immunosuppressive drugs may cause secondary ID.KEY POINTSCompared to the population, the frequency of Th2-mediated allergic diseases is lower in oligoarthritis and RF-negative polyarthritis that are primarily driven by a Th1 activity.The coexistence of allergic diseases in juvenile idiopathic arthritis does not affect the severity of arthritis.Pulmonary function tests can be thought to be obtained periodically in juvenile idiopathic arthritis.Immunological workup should be considered in atypically or severely presented patients with juvenile idiopathic arthritis before the initiation of immunosuppressive therapy to differentiate primary and secondary immunodeficiency.

Association of diabetes-related autoantibodies with the incidence of asthma, eczema and allergic rhinitis in the TRIGR randomised clinical trial

AIMS/HYPOTHESIS

This paper presents the relationship between islet autoantibodies, precursors of type 1 diabetes, and the development of persistent asthma, allergic rhinitis and atopic eczema.

METHODS

A total of 2159 newborns who had a first-degree relative with type 1 diabetes and selected HLA genotypes were followed until the youngest participant reached 10 years of age. Islet cell antibodies (ICA) were detected using indirect immunofluorescence. Autoantibodies to insulin (IAA), GAD (GADA), the tyrosine phosphatase-related insulinoma-associated 2 molecule (IA-2A) and zinc transporter 8 (ZnT8A) were quantified with the use of specific radiobinding assays. As an ancillary study, the incidence of asthma, allergic rhinitis and eczema was assessed in 1106 of these children using the International Study of Asthma and Allergies in Childhood (ISAAC) core questionnaire when the children were 9-11 years old. HRs with 95% CIs were calculated to depict the incidence of these diseases following seroconversion to autoantibody positivity.

RESULTS

The cumulative incidence of atopic eczema, allergic rhinitis and persistent asthma were 22%, 9% and 7.5%, respectively, by 9-11 years of age. The occurrence of diabetes-related autoantibodies showed a protective association with subsequently reported incidence of asthma and eczema. The incidence of rhinitis was not significantly related to the occurrence of IAA or GADA (statistical power was limited), but demonstrated the same inverse relationship as did the other diseases with ICA or when multiple autoantibodies first appeared together.

CONCLUSIONS/INTERPRETATION

The findings add evidence to the relationships between these atopic diseases and diabetes-related autoimmunity and also suggest that, for eczema, the interaction depends upon which autoantibody appeared first.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00179777 Graphical abstract.

Use of Antiasthmatic Drugs and the Risk of Type 1 Diabetes in Children: A Nationwide Case-Cohort Study

Asthma has been reported to be associated with an increased risk of type 1 diabetes mellitus in childhood, but the reasons are unclear. We examined whether the use of antiasthmatic drugs was associated with the development of type 1 diabetes in childhood in a nationwide, register-based case-cohort study. We identified all children who were born January 1, 1995, through December 31, 2008, in Finland and diagnosed with type 1 diabetes by 2010 (n = 3,342). A 10% random sample from each birth-year cohort was selected as a reference cohort (n = 80,909). Information on all dispensed antiasthmatic drugs (Anatomical Therapeutic Chemical classification system code R03) during 1995-2009 was obtained, and associations between the use of antiasthmatic drugs and the development of type 1 diabetes were investigated using time-dependent and time-sequential Cox regression models. Dispensed inhaled corticosteroids and inhaled β-agonists were associated with an increased risk of type 1 diabetes after adjusting for other antiasthmatic drugs, asthma, sex, and birth decade (hazard ratio = 1.29, 95% confidence interval: 1.09, 1.52, and hazard ratio = 1.22, 95% confidence interval: 1.07, 1.41, respectively). These findings suggest that children using inhaled corticosteroids or inhaled β-agonists might be at increased risk of type 1 diabetes.

Familial Coaggregation of Asthma and Type 1 Diabetes in Children

IMPORTANCE

The association between atopic and autoimmune disease, particularly asthma and type 1 diabetes, has been debated. Further understanding of the underlying factors associated with the comorbidity in children is warranted.

OBJECTIVES

To assess the bidirectional association between asthma and type 1 diabetes and examine the possibility of a shared risk for the diseases by studying their pattern of familial coaggregation.

DESIGN, SETTING, AND PARTICIPANTS

A birth cohort study of children born from January 1, 2001, and followed up until December 31, 2015, was performed. Population data were obtained from multiple national Swedish registers. A total of 1 347 901 singleton children, live-born in Sweden between January 1, 2001, and December 31, 2013, were identified, and children with incomplete data were excluded. The remaining 1 284 748 children were linked to their biological full siblings, maternal and paternal half-siblings, cousins, and half-cousins. Data analysis was conducted from April 1, 2019, to January 17, 2020.

MAIN OUTCOMES AND MEASURES

Cases of asthma and type 1 diabetes were defined using a combination of diagnoses and medication prescriptions found in the registers.

RESULTS

In the cohort of 1 284 748 children, 660 738 children (51.4%) were boys; 121 809 children (9.5%) had asthma, 3812 children (0.3%) had type 1 diabetes, and 494 children had both asthma and type 1 diabetes, representing 0.4% of all asthma or 13% of all type 1 diabetes. Mean (SD) age at diagnosis was 3.0 (2.8) years for children with asthma, and 5.9 (3.3) years for those with type 1 diabetes. Asthma and type 1 diabetes were associated within individuals (odds ratio, 1.15; 95% CI, 1.05-1.27). Children with asthma had an increased risk of subsequent type 1 diabetes (hazard ratio, 1.16; 95% CI, 1.06-1.27); however, subsequent asthma risk did not differ substantially among children with type 1 diabetes (hazard ratio, 0.92; 95% CI, 0.75-1.12). Siblings of individuals with asthma were at an increased risk of type 1 diabetes (odds ratio, 1.27; 95% CI, 1.13-1.42) and vice versa. The results remained positive after controlling for the direct association of one disease with the other.

CONCLUSIONS AND RELEVANCE

This study appears to provide evidence for co-occurrence, importance of sequential appearance, and coaggregation of asthma and type 1 diabetes in children and their siblings. The findings may suggest shared familial factors contributing to the associations. Knowledge of the nature of the association could be of importance in future clinical practice.

Diabetic lung disease: fact or fiction?

Diabetes mellitus is a chronic, progressive, incompletely understood metabolic disorder whose prevalence has been increasing steadily worldwide. Even though little attention has been paid to lung disorders in the context of diabetes, its prevalence has recently been challenged by newer studies of disease development. In this review, we summarize and discuss the role of diabetes mellitus involved in the progression of pulmonary diseases, with the main focus on pulmonary fibrosis, which represents a chronic and progressive disease with high mortality and limited therapeutic options.

Reduced mortality from lower respiratory tract disease in adult diabetic patients treated with metformin

BACKGROUND AND OBJECTIVE

Chronic lower respiratory diseases (CLRD) increase the risk of type 2 diabetes, which in turn may worsen lung function. Metformin, a common antidiabetic with anti-inflammatory and antioxidant properties, may improve respiratory outcomes. Therefore, we examined the association of metformin use with the risk of mortality from CLRD.

METHODS

We analysed data from the National Health and Nutrition Examination Survey during 1988-1994 and 1999-2010 for participants aged 40 years or older who had diabetes and were followed up for mortality through 2011. Information on prescription medicine was collected at baseline and CLRD-related mortality during follow-up was defined using the 10th Revision of the International Classification of Diseases (ICD-10). Cox proportional hazards modelling was used to determine the mortality hazard ratio (HR) associated with metformin use, adjusting for relevant covariates.

RESULTS

A total of 5266 participants with a median follow-up of 6.1 years were included. The prevalence of metformin use was 31.9% and 1869 participants died during follow-up, including 72 of CLRD. In the adjusted Cox proportional regression analysis, metformin was associated with a decreased risk of CLRD mortality in the overall population (HR: 0.39, 95% CI: 0.15-0.99) and among participants with baseline CLRD (HR: 0.30, 95% CI: 0.10-0.93), after adjusting for age, gender, race/ethnicity, cigarette smoking, body mass index, current asthma and chronic obstructive pulmonary disease (COPD), insulin and other diabetic medications, and glycohaemoglobin level. We found no association between other antidiabetic medications and CLRD mortality.

CONCLUSION

In this sample representative of the U.S. population, metformin was associated with lower CLRD mortality in adults with diabetes.

Atopic eczema and major cardiovascular outcomes: A systematic review and meta-analysis of population-based studies

BACKGROUND

Atopic eczema is a common inflammatory skin disease. Various inflammatory conditions have been linked to cardiovascular disease, a major cause of global mortality and morbidity.

OBJECTIVE

We sought to systematically review and meta-analyze population-based studies assessing associations between atopic eczema and specific cardiovascular outcomes.

METHODS

MEDLINE, Embase, and Global Health were searched from inception to December 2017. We obtained pooled estimates using random-effects meta-analyses. We used a multivariate Bayesian meta-regression model to estimate the slope of effect of increasing atopic eczema severity on cardiovascular outcomes.

RESULTS

Nineteen relevant studies were included. The effects of atopic eczema reported in cross-sectional studies were heterogeneous, with no evidence for pooled associations with angina, myocardial infarction, heart failure, or stroke. In cohort studies atopic eczema was associated with increased risk of myocardial infarction (n = 4; relative risk [RR], 1.12; 95% CI, 1.00-1.25), stroke (n = 4; RR, 1.10; 95% CI, 1.03-1.17), ischemic stroke n = 4; RR, 1.17; 95% CI, 1.14-1.20), angina (n = 2; RR, 1.18; 95% CI, 1.13-1.24), and heart failure (n = 2; RR, 1.26; 95% CI, 1.05-1.51). Prediction intervals were wide for myocardial infarction and stroke. The risk of cardiovascular outcomes appeared to increase with increasing severity (mean RR increase between severity categories, 1.15; 95% credibility interval, 1.09-1.21; uncertainty interval, 1.04-1.28).

CONCLUSION

Significant associations with cardiovascular outcomes were more common in cohort studies but with considerable between-study heterogeneity. Increasing atopic eczema severity was associated with increased risk of cardiovascular outcomes. Improved awareness among stakeholders regarding this small but significant association is warranted.

The association between asthma and type 1 diabetes: a paediatric case-cohort study in Finland, years 1981-2009

Background

The association between asthma and type 1 diabetes, two chronic, immune-mediated diseases, has been of longstanding interest, but the evidence is still conflicting. We examined this association in a large, nationwide case-cohort study among Finnish children, using a novel statistical approach.

Methods

Among the initial cohort of all children born between 1 January 1981 and 31 December 2008, those who were diagnosed with asthma (n = 81 473) or type 1 diabetes (n = 9541) up to age 16 years by the end of 2009 were identified from the Central Drug Register maintained by the Social Insurance Institution of Finland. A 10% random sample from each initial birth year cohort was selected as a reference cohort (n = 171 138). The association between asthma and type 1 diabetes was studied using a multistate modelling approach to estimate transition rates between healthy and disease states since birth. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to represent the change in the transition rate between the disease states.

Results

After adjusting for sex and birth decade, previous diagnosis of asthma increased the risk of subsequent type 1 diabetes by 41% (95% CI: 1.28, 1.54), whereas previous diagnosis of type 1 diabetes decreased the risk of subsequent asthma by 18% (95% CI: 0.69, 0.98).

Conclusions

The findings of the present study imply that the association between the diseases is more complex than previously thought, and its direction depends on the sequential appearance of the diseases.

Association between parental autoimmune disease and atopic dermatitis in their offspring: a matched case-control study

BACKGROUND

Atopic dermatitis (AD) is associated with many autoimmune diseases, in part due to overlapping genetic risk loci. While parental atopic disease is an important risk for AD in the offspring, little is known on the putative associations between parental autoimmune disease and AD in their children.

MATERIALS AND METHODS

All children born between 1996 and 2011 who received a diagnosis of AD in the hospital system before their fifth birthday were matched 1 : 10 with children from the general population. Maternal and paternal autoimmune diseases were assessed using registry-based data. Conditional logistic regression was performed on the relationships between parental autoimmune diseases and AD in their children.

RESULTS

A total of 8589 children with AD were matched with controls. One or more autoimmune disease was identified in 5.89% (506/8589) of mothers to AD children and 3.67% (315/8589) of fathers to AD children compared to 4.85% (4163/85 890) and 3.28% (2816/85 890) in parents of control children. Maternal autoimmune disease but not paternal autoimmune disease was associated with AD in the offspring (odds ratio [OR] 1.20 [95% confidence interval (CI) 1.20-1.32] and OR 1.08 [0.96-1.22], respectively), Two or more maternal autoimmune diseases, maternal dermatologic autoimmune disease and maternal digestive autoimmune disease were all also associated with AD development in her children (1.96 [95% CI 1.36-2.84], OR 1.60 [95% CI 1.24-2.07] and OR 1.24 [95% CI 1.06-1.45], respectively).

CONCLUSIONS

The risk of AD is influenced by many factors including atopy status and filaggrin gene mutations. In this matched case-control study, maternal autoimmune disease was associated with AD diagnosis in the offspring. Maternal dermatologic and digestive autoimmune diseases were most closely associated with subsequent AD diagnosis in the offspring.

Asthma in children and adolescents with type 1 diabetes in Germany and Austria: Frequency and metabolic control

OBJECTIVE

To investigate the prevalence of asthma in young patients with type 1 diabetes mellitus (T1D) from Austria and Germany and its influence on their metabolic control.

METHODS

This prospective, multicenter observational cohort study was based on the DPV-registry (German/Austrian DPV initiative) including 51 926 patients with T1D (<20 years). All clinical data were documented prospectively. To identify patients with additional asthma, the entry of the diagnosis asthma as well as asthma medication was used for classification.

RESULTS

1755 patients (3.4%) of the cohort had the diagnosis asthma or received asthma-specific drugs. Patients with asthma needed higher insulin doses (0.88 ± 0.3 vs 0.84 ± 0.3 U/kg, P < .01) and had decreased height-standard deviation score (SDS) (-0.002 ± 1.04 vs 0.085 ± 1.02, P < .01); they were more often males (61% vs 52%, P < .01), had an increased body mass index (BMI)-SDS (0.31 ± 0.89 vs 0.28 ± 0.89, P = .04) and experienced more severe hypoglycemia (4.5 [4.2; 4.8] vs 3.2 [3.2; 3.3] events/100 pts. years, P < .01). Glycated hemoglobin A1c (HbA1c) did not differ between patients with and without asthma overall, only sub groups (corticosteroids vs leukotriene antagonist and corticosteroids vs sympatomimetics) revealed differences. No influence of asthma medication on metabolic control or BMI-SDS could be found.

CONCLUSION

In our DPV-database, frequency of asthma and T1D seems similar to the prevalence of asthma in the healthy German background population. The concomitant diagnosis of asthma and T1D had minor influence on metabolic control and diabetes complication rate, although there was no difference in HbA1c overall. Patients with both diseases seem to be slightly growth restricted and require slightly higher insulin doses.

Skin diseases associated with atopic dermatitis

Atopic dermatitis is a common chronic pruritic inflammatory skin disorder, characterized by an abnormal skin barrier, immune dysfunction, and an altered skin microbiome. Atopic dermatitis may be seen in conjunction with a variety of other skin disorders due to the complex pathogenesis of atopic dermatitis, involving genetic and environmental factors that are associated with immune dysfunction, barrier defects, and altered skin microbiomes. Skin disorders associated with atopic dermatitis include diseases sharing similar genetic origins like ichthyosis vulgaris, infectious diseases such as impetigo, and eczema herpeticum, in addition to the cutaneous autoimmune diseases, alopecia areata, and vitiligo. Atopic dermatitis is also often linked to such benign conditions as pityriasis alba and keratosis pilaris. This review discusses the cutaneous comorbidities of atopic dermatitis and their relationship via their occurrence in conjunction with atopic dermatitis.

Pleiotropic effects of hypoglycemic agents: implications in asthma and COPD

Diabetes mellitus (DM) is a complex multifactorial disease due to the interaction between environmental noxae and genetic predisposition. Furthermore, an increased association between DM, especially Type 2 diabetes mellitus (T2DM), and the onset of pulmonary function impairment with a bronchial hyperresponsiveness has been documented. DM is a risk factor for accelerated decline in FEV₁ and the development of asthma and COPD. The increased blood glucose concentrations along with higher levels of oxidative stress and inflammation can influence the pulmonary function and, since hypoglycemic drugs can act on these different defects we can hypothesize their direct effect on obstructive pulmonary diseases. Metformin, a biguanide, is the molecule having several evidences of its action on asthma and COPD in patients with T2DM. In this population, Metformin can ameliorate pulmonary outcomes reducing high glucose concentrations, inflammation through the activation of the AMP-activated protein kinase, leading to the decreased production of pro-inflammatory cytokines and blunting allergic eosinophilic airway inflammation. There are evidences of Pioglitazone role on asthma, since the activation of PPARγ Pioglitazone might inhibit the synthesis and release of pro-inflammatory cytokines. Indeed, Pioglitazone can improve symptoms associated with asthma reducing episodes of exacerbation and oral steroid prescription. Finally, randomized clinical trials using hypoglycemic agents on patients with asthma and COPD with and without DM should be proposed as well as the implementation of a new formulation of hypoglycemic agents to make it possible to administer it via aerosol.

Transcriptional and Functional Plasticity Induced by Chronic Insulin Exposure in a Mast Cell-Like Basophilic Leukemia Cell Model

Objective

Secretory granules (SG) and lipid bodies (LB) are the primary organelles that mediate functional responses in mast cells. SG contains histamine and matrix-active proteases, while LB are reservoirs of arachidonic acid and its metabolites, precursors for rapid synthesis of eicosanoids such as LTC₄. Both of these compartments can be dynamically or ontologically regulated, with metabolic and immunological stimuli altering lipid body content and granule numbers responding to contextual signals from tissue. We previously described that chronic in vitro or in vivo hyperinsulinemia expands the LB compartment with a concomitant loss of SG capacity, suggesting that this ratio is dynamically regulated. The objective of the current study is to determine if chronic insulin exposure initiates a transcriptional program that biases model mast cells towards a lipogenic state with accompanying loss of secretory granule biogenesis.

Methods

We used a basophilic leukemic cell line with mucosal mast cell-like features as a model system. We tested the hypothesis that chronic insulin exposure initiates a transcriptional program that biases these model mast cells towards a lipogenic state with accompanying loss of secretory granule biogenesis. Transcriptional arrays were used to map gene expression patterns. Biochemical, immunocytochemical and mediator release assays were used to evaluate organelle numbers and functional responses.

Results

In a mucosal mast cell model, the rat basophilic leukemia line RBL2H3, mast cell granularity and SG numbers are inversely correlated with LB numbers. Chronic insulin exposure appears to modulate gene networks involved in both lipid body biogenesis and secretory granule formation. Western blot analysis confirms upregulation of protein levels for LB proteins, and decreases in proteins that are markers for SG cargo.

Conclusions

The levels of insulin in the extracellular milieu may modify the phenotype of mast cell-like cells in vitro.

Type 1 diabetes in children and adolescents is not associated with a reduced prevalence of atopy and allergic diseases

BACKGROUND

Type 1 diabetes mellitus (T1D) as well as allergies in childhood have increased worldwide during the last 2 decades. The reasons for this increase are still unknown but early life origins are being discussed, such as dietary and hygiene factors that may play a role in the development of both diseases. The aim of this study was to compare the prevalence of allergies in children with and without T1D and to define potential influencing factors.

MATERIALS AND METHODS

Data were collected from 104 patients with T1D (n = 104; mean age 11.4 ± 4.4 years; m/f: 77/27) and 104 healthy controls (CG) (n = 104; mean age 11.4 ± 4.3 years; m/f: 77/27). A questionnaire on allergic symptoms was obtained from each individual. In parallel, ImmunoCAP tests to detect specific allergen sensitization were performed.

RESULTS

Allergen sensitization rates were not significantly different between both groups (T1D: 42% vs CG 38%; P = 0.625). In both groups, a comparable number of patients reported allergic symptoms in the questionnaire (T1D: 20% vs CG 26%; P = 0.43). Allergen sensitization and allergic symptoms were independent of breastfeeding, pets at home or diabetes duration. However, in T1D, fewer family members smoked (T1D: 10% vs CG 56%; P < 0.001).

CONCLUSIONS

The present cohort study shows the same prevalence of allergy and atopy in a pediatric diabetes population compared to healthy controls. Diabetes per se does not seem to influence the development of allergies.

Association between eczema and major cardiovascular outcomes in population-based studies: a systematic review protocol

INTRODUCTION

Chronic inflammatory diseases such as eczema (also known as atopic dermatitis) have been inconsistently linked to cardiovascular disease and stroke in both mechanistic and epidemiological studies. There is a need to review the existing epidemiological data examining the association between eczema and major cardiovascular outcomes, including angina, myocardial infarction, coronary revascularisation, heart failure, cardiac arrhythmias, stroke and cardiovascular death, in order to improve our understanding of the comorbidities of eczema.

METHODS AND ANALYSIS

We will systematically review population-based studies, including cohort, case-control and cross-sectional studies, reporting on the association between eczema and cardiovascular outcomes. We will search Medline, Embase and Global Health, from their date of inception to April 2017, using a comprehensive search strategy formulated with the help of a librarian. Two reviewers will independently screen titles and abstracts in duplicate, followed by independent data extraction and quality assessment. We will group studies by the cardiovascular outcome under study and synthesise them narratively. If sufficient numbers of homogeneous studies are returned, we will perform meta-analyses to obtain pooled effect estimates. Preferred Reporting Items for Systematic Review and Meta-Analysis will be used to inform the reporting of this study.

TRIAL REGISTRATION NUMBER

CRD42017060359.

Filaggrin loss-of-function mutations as risk factors for ischemic stroke in the general population

Essentials FLG mutations cause atopic dermatitis, previously found to be associated with ischemic stroke. Association between FLG mutations and ischemic stroke was examined in 97 174 Danish individuals. FLG mutations were associated with increased ischemic stroke risk in the general population. The association was most pronounced in younger individuals, and in current and former smokers.

SUMMARY

Background Heritability studies have shown a considerable genetic component to ischemic stroke risk; however, much is unknown as to which genes are responsible. Also, previous studies have found an association between atopic dermatitis and increased ischemic stroke risk. Objective To test the hypothesis that FLG loss-of-function mutations, known to be associated with atopic dermatitis, were also associated with ischemic stroke. Methods A total of 97 174 individuals, with 3597 cases of ischemic stroke, from the Copenhagen General Population Study, the Copenhagen City Heart Study and the Copenhagen Carotid Stroke Study were genotyped for the two most common filaggrin mutations, FLG R501X and FLG 2282del4. Results FLG mutation carriers had an odds ratio for ischemic stroke of 1.15 (95% confidence interval [CI], 1.02-1.30) compared with non-carriers. Risk of ischemic stroke for FLG mutation carriers was higher among individuals aged < 50 years, with an odds ratio of 1.72 (1.11-2.67), compared with non-carriers. When stratified for smoking, ischemic stroke risk was primarily seen in current and former smokers, with an odds ratio of 1.25 (1.08-1.44). FLG mutations were not associated with conventional cardiovascular risk factors except for slightly more pack-years smoked among mutation carriers, but were associated with increased risk of self-reported eczema, with an odds ratio of 1.42 (1.32-1.52). Finally, self-reported eczema was associated with increased ischemic stroke risk, with an age and sex adjusted hazard ratio of 1.24 (1.01-1.52); however, the association was not statistically significant after multifactorial adjustment. Conclusion In this study of 97 174 individuals from the Danish general population, FLG loss-of-function mutations were associated with increased ischemic stroke risk; however, residual confounding is a possibility.

Diabetes mellitus in childhood: an emerging condition in the 21st century

The International Diabetes Federation (IDF-2015) estimates the existence of 30,900 children under 15 years old with type 1 diabetes mellitus (DM1) in Brazil, and an increase of 3.0% per year is expected. This review focused on meta-analysis and pediatric diabetes update articles in order to draw attention to the need of planning coping strategies to support this serious public health problem in coming years. DM1 is considered an immuno-mediated disease with a complex transmission influenced by genetic and environmental factors responsible for a gradual destruction of the insulin producing pancreatic beta cells. Seroconversion to DM1-associated autoantibodies and abnormalities in metabolic tests that assess insulin secretion and glucose tolerance can be used as predictive criteria of beta cells functional reserve and the onset of the clinical disease. Symptomatic DM1 treatment is complex and the maintenance of good metabolic control is still the only effective strategy for preserving beta cell function. Disease duration and hyperglycemia are both risk factors for the onset of chronic vascular complications that negatively affect the quality of life and survival of these patients. In this regard, health teams must be trained to provide the best possible information on pediatric diabetes, through continuing education programs focused on enabling these young people and their families to diabetes self-management.

Comorbidities of Atopic Dermatitis: Beyond Rhinitis and Asthma

PURPOSE OF REVIEW

In this review article, we summarize the current evidence about atopic dermatitis (AD)-associated comorbidities, beyond the traditional atopic and allergic conditions.

RECENT FINDINGS

Patients with AD may have an increased risk of cardiovascular diseases, certain malignancies, autoimmune diseases, and neuropsychiatric diseases. The causes of these associations are likely multifactorial and may include genetic predispositions, systemic low-grade inflammation, environmental exposures, medication, and lifestyle and behavioral risk factors. There appears to be geographical variations in prevalence of comorbidities in patients with AD, indicating that differences in ethnicity and lifestyle factors may significantly influence the risk of certain comorbidities.

SUMMARY

The reported comorbidities in recent literature emphasize the burden of disease in patients with AD. Early appropriate AD therapy, in combination with reduction of risk factors, may help prevention of certain comorbidities. The reported observations may generate hypotheses for future investigations in underlying risk factors for AD-associated comorbidities.

Asthma related medication use and exacerbations in children and adolescents with type 1 diabetes

OBJECTIVES

To investigate the use of asthma medication and occurrence of asthma exacerbations up to 5 years before and after the onset of type 1 diabetes mellitus (T1DM) in children and adolescents.

METHODS

Children and adolescents younger than 19 years with at least 2 insulin prescriptions between 1999 and 2009 classified as T1DM cohort (n = 915) and a 4 times larger reference cohort (n = 3,590) with the same age and gender were identified from the Dutch PHARMO Record Linkage System. The date of first insulin dispensing was selected as the index date.

RESULTS

The 5-year prevalence rate of asthma medication use in the T1DM cohort (23.2%) was significantly higher than the reference cohort (18.3%) after the onset of diabetes. No statistically significant difference between the two cohorts was observed in the use of specific types of asthma medication except for short acting muscarinic antagonists that were significantly more used in the T1DM cohort (5.5%) compared with the reference cohort (0.62%) after the onset of diabetes. The incidence rate of asthma medication use declined over time with a peak in the T1DM cohort the 1st year after the onset of diabetes. Furthermore, 1 year after the index date there was a peak in incidence rate of asthma exacerbations in both T1DM (7.8 per 1,000 person year) and reference (6.8 per 1,000 person year) cohorts.

CONCLUSIONS

T1DM is associated with statistically significantly higher asthma medication use after the onset of T1DM, especially in the 1st year after the onset of diabetes. Pediatr Pulmonol. 2016;51:1113-1121. © 2016 Wiley Periodicals, Inc.

Bacillus Calmette-Guérin (BCG) Vaccination in Infancy and Risk of Childhood Diabetes

BACKGROUND

A narrow time window in infancy may be relevant for the aetiology of immune-mediated type 1 diabetes. We investigated whether a non-specific immune stimulation in the first year of life, as resulting from Bacillus Calmette-Guérin (BCG) vaccination, was associated with childhood diabetes.

METHODS

Using data from a birth cohort assembled through linkage of administrative databases, 78,492 subjects born in 1974 were the object of the present analysis. Information was extracted from the birth, death, and BCG vaccination registries. Diabetes-related health services were obtained from administrative health databases (physician billing claims and hospitalisation data) until 1994. Subjects were classified as having diabetes according to two validated definitions: (1) ≥2 diabetes-related medical visits within 2 years or ≥1 hospitalisation for diabetes; and 2) ≥4 diabetes-related medical visits within 2 years. Cox proportional hazards regression was used to estimate adjusted hazard ratios (HR) and 95% confidence interval (CI), adjusted for potential confounders.

RESULTS

Forty-four per cent of subjects were BCG vaccinated in the first year of life. According to the first and second definition, respectively, 293 (0.37%) and 230 (0.29%) subjects were classified as having diabetes. There was no association between BCG vaccination in the first year of life and risk of diabetes with either definition (HR(def1)  = 0.92, 95% CI 0.73, 1.17; HR(def2)  = 1.04, 95% CI 0.80, 1.37), and results did not differ by sex.

CONCLUSIONS

Given the potentially critical importance of the exposure window and paucity of studies addressing BCG vaccination timing in relation to diabetes risk, this question deserves further investigation.

[Nonallergic comorbidities of atopic dermatitis]

BACKGROUND

Recognizing the whole spectrum of comorbidities related to atopic dermatitis (AD) is prerequisite for adequate, patient-centered care.

OBJECTIVES

Based on systematic reviews (SRs) and published case-control studies, the current evidence on nonallergic comorbidities of AD is summarized.

MATERIALS AND METHODS

A comprehensive systematic literature search was performed in Medline and Embase (Search period: through 15 November 2014).

RESULTS

In total, nine systematic reviews were included. Six reviews investigating the association between AD and cancer suggested a decreased risk of glioma, meningioma, and acute lymphoblastic leukemia in patients with current or previous AD. One SR reported a consistent positive association of AD with attention deficit hyperactivity disorder. In comparison, two SRs focusing on the relationship between AD and diabetes mellitus type 1 and multiple sclerosis showed that there is no evidence supporting an association. A further screening of individual observational studies concerning immunological and psychiatric diseases pointed out that AD seems to be a significant risk factor for Crohn's disease, affective, schizophrenic, and behavior disorders.

CONCLUSION

Further longitudinal studies are needed to verify the existence of causal relationships. Interdisciplinary working groups are desirable to investigate explanations for genetic and physiologic mechanisms of described associations between AD and nonallergic comorbidities.

Meta-analysis derived atopic dermatitis (MADAD) transcriptome defines a robust AD signature highlighting the involvement of atherosclerosis and lipid metabolism pathways

Background

Atopic dermatitis (AD) is a common inflammatory skin disease with limited treatment options. Several microarray experiments have been conducted on lesional/LS and non-lesional/NL AD skin to develop a genomic disease phenotype. Although these experiments have shed light on disease pathology, inter-study comparisons reveal large differences in resulting sets of differentially expressed genes (DEGs), limiting the utility of direct comparisons across studies.

Methods

We carried out a meta-analysis combining 4 published AD datasets to define a robust disease profile, termed meta-analysis derived AD (MADAD) transcriptome.

Results

This transcriptome enriches key AD pathways more than the individual studies, and associates AD with novel pathways, such as atherosclerosis signaling (IL-37, selectin E/SELE). We identified wide lipid abnormalities and, for the first time in vivo, correlated Th2 immune activation with downregulation of key epidermal lipids (FA2H, FAR2, ELOVL3), emphasizing the role of cytokines on the barrier disruption in AD. Key AD “classifier genes” discriminate lesional from nonlesional skin, and may evaluate therapeutic responses.

Conclusions

Our meta-analysis provides novel and powerful insights into AD disease pathology, and reinforces the concept of AD as a systemic disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12920-015-0133-x) contains supplementary material, which is available to authorized users.

The contribution of twin studies to the understanding of the aetiology of asthma and atopic diseases

The prevalence of asthma and other atopic diseases has increased markedly during the past decades and the reasons for this are not fully understood. Asthma is still increasing in many parts of the world, notably in developing countries, and this emphasizes the importance of continuing research aimed at studying the aetiological factors of the disease and the causes of its increase in prevalence. Twin studies enable investigations into the genetic and environmental causes of individual variation in multifactorial diseases such as asthma. Thorough insight into these causes is important as this will ultimately guide the development of preventive strategies and targeted therapies. This review explores the contribution of twin studies to the understanding of the aetiology of asthma and atopic diseases.

Type 1 Diabetes and Increased Risk of Subsequent Asthma: A Nationwide Population-Based Cohort Study

The association between type 1 diabetes mellitus (T1DM) and asthma remains controversial and has led to new interest in these 2 disorders. The purpose of this study was to examine the associations among young people with T1DM and asthma and offer a clinical demonstration of the balance between Th1 and Th2 responses.We conducted a retrospective cohort study by using data from the National Health Insurance (NHI) system of Taiwan. The cohort consisted of 3545 T1DM cases and 14,180 controls established during the 1998 to 2011 period. Of the 3545 T1DM patients, 55.1% were girls and 26.5% were in the age group <8 years.The overall incidence of asthma was 47% higher in the T1DM cohort than in the control cohort (6.49 vs 4.42 per 1000 person-y), with an adjusted hazard ratio (HR) of 1.34 (95% confidence interval [CI] = 1.11-1.62). Moreover, T1DM patients who visited the emergency room (ER) more than twice for diabetes had a higher adjusted HR of 17.4 (95% CI = 12.9-23.6) of developing asthma. The adjusted HR of asthma was 38.6 (95% CI = 28.5-52.2) in T1DM patients who had been hospitalized more than twice for diabetes.We observed a significantly higher incidence of asthma in young patients with T1DM than in the general population. Among young people of T1DM with more ER visits or frequent hospitalization because of diabetes mellitus were associated with risk of asthma, may indicate that poor glycemic control significantly contributes to asthma risk.

Prevalence of allergic diseases and/or allergic sensitisation in children and adolescents with type 1 diabetes mellitus

BACKGROUND

The prevalence of atopic diseases in children with type 1 diabetes mellitus (DM1) has been reported as lower. The aim of this study was to evaluate the prevalence of allergic diseases and allergic sensitisation in Brazilian children and adolescents with DM1.

PATIENTS AND METHODS

96 patients with DM1 (aged 4-18 years, 45 boys) followed for at least one year were evaluated for allergic disease through a detailed allergological anamnesis and skin prick tests (SPT) to inhalant allergens (Dermatophagoides pteronyssinus, D. farinae, Blomia tropicalis, Blattella germanica, Periplaneta americana, dog epithelium, cat epithelium, mix fungi), foods (cow's milk, egg-white, yolk, soy, wheat, corn), and positive (histamine 1 mg/ml) and negative (saline) controls. Wheals with a mean diameter of induration equal to or greater than 3mm identified a positive SPT.

RESULTS

The prevalence values of rhinitis, asthma and atopic eczema (isolated or associated) were 68.0%, 59.1% and 44.4%, respectively. 20.6% of the patients had no allergic disease. 46.8% of the patients had been diagnosed with DM1 for at least four years and there was no relationship between the period of DM1 and the presence of allergic disease, nor of the gender. 48.0% patients were sensitised with predominance of D. pteronyssinus, B. topicalis and D. farinae. The frequency of positive SPT was significantly higher among patients with history of allergic disease (OR=6.98, 95%CI: 2.60-18.74, p<0.001).

CONCLUSION

The prevalence of allergic diseases and sensitisation in patients with DM1 was higher than usually expected and deserves further investigation to identify possible causes for these findings and to evaluate their importance and influence on the metabolic control.

Exploring the origins of asthma: Lessons from twin studies

This thesis explores the contribution of twin studies, particularly those studies originating from the Danish Twin Registry, to the understanding of the aetiology of asthma. First, it is explored how twin studies have established the contribution of genetic and environmental factors to the variation in the susceptibility to asthma, and to the variation in several aspects of the clinical expression of the disease such as its age at onset, its symptomatology, its intermediate phenotypes, and its relationship with other atopic diseases. Next, it is explored how twin studies have corroborated theories explaining asthma's recent increase in prevalence, and last, how these fit with the explanations of the epidemiological trends in other common chronic diseases of modernity.

Diabetes in the young - a global view and worldwide estimates of numbers of children with type 1 diabetes

This paper describes the methodology, results and limitations of the 2013 International Diabetes Federation (IDF) Atlas (6th edition) estimates of the worldwide numbers of prevalent cases of type 1 diabetes in children (<15 years). The majority of relevant information in the published literature is in the form of incidence rates derived from registers of newly diagnosed cases. Studies were graded on quality criteria and, if no information was available in the published literature, extrapolation was used to assign a country the rate from an adjacent country with similar characteristics. Prevalence rates were then derived from these incidence rates and applied to United Nations 2012 Revision population estimates for 2013 for each country to obtain estimates of the number of prevalent cases. Data availability was highest for the countries in Europe (76%) and lowest for the countries in sub-Saharan Africa (8%). The prevalence estimates indicate that there are almost 500,000 children aged under 15 years with type 1 diabetes worldwide, the largest numbers being in Europe (129,000) and North America (108,700). Countries with the highest estimated numbers of new cases annually were the United States (13,000), India (10,900) and Brazil (5000). Compared with the prevalence estimates made in previous editions of the IDF Diabetes Atlas, the numbers have increased in most of the IDF Regions, often reflecting the incidence rate increases that have been well-documented in many countries. Monogenic diabetes is increasingly being recognised among those with clinical features of type 1 or type 2 diabetes as genetic studies become available, but population-based data on incidence and prevalence show wide variation due to lack of standardisation in the studies. Similarly, studies on type 2 diabetes in childhood suggest increased incidence and prevalence in many countries, especially in Indigenous peoples and ethnic minorities, but detailed population-based studies remain limited.

Nonallergic comorbidities of atopic eczema: an overview of systematic reviews

The aims of this overview are to synthesize the current evidence of published systematic reviews (SRs) on nonallergic comorbidities of atopic eczema (AE). EMBASE and MEDLINE were searched for SRs published from inception to November 2012. SRs were selected independently based on predefined inclusion criteria. Methodological quality of SRs included was assessed by two independent reviewers using the Revised Assessment of Multiple Systematic Reviews (R-AMSTAR) checklist. Nine SRs met all inclusion criteria. Six reviews addressing the association between AE and cancer suggest a decreased risk of glioma, meningioma, and acute lymphoblastic leukemia in patients with current or previous AE. One SR reported a consistent positive association of AE with attention-deficit hyperactivity disorder (ADHD). Diabetes mellitus type 1 and multiple sclerosis (MS) were not significantly related to AE in reviews based on cross-sectional and case-control studies. Patients with AE appear to be at decreased risk of brain tumors. The relationship of AE with Th1- and Th17-mediated (auto-)inflammatory conditions such as diabetes mellitus type 1 and MS should be clarified in prospective observational studies. Children with AE are at increased risk of ADHD. SRs on the risk of depression and Th17-mediated disorders such as inflammatory bowel disease of patients with AE are missing.

Obesity and asthma at school entry: co-morbidities and temporal trends

AIM

A decline in asthma prevalence from 2000 to 2005 was reported previously. The objective is to examine the temporal trends for the prevalence of obesity and other childhood disorders and consider the extent to which associations between asthma and other co-morbidities can be accounted for by body mass index.

METHODS

Serial cross-sectional surveys of primary school entrants (n = 18,999) in the Australian Capital Territory between 2001 and 2005 were used. Asthma, recent respiratory symptoms and diabetes data were extracted from parental reports. Anthropometric measurements were obtained from health assessments by school nurses. Child obesity was defined using the age and sex-specific Cole criteria. Time trends for the prevalence of obesity and other disorders, and the association between 'current asthma' and co-morbidities were analysed using multiple logistic regression and other analyses.

RESULTS

Obesity prevalence was 5.24% in 2001 decreasing to 3.60% in 2005 (test of linear trend P = 0.02). Overweight (adjusted odds ratio (AOR) 1.30 (95% confidence interval (CI) 1.16, 1.46), P < 0.001) and obese (AOR 1.36 (95% CI 1.13, 1.62), P = 0.001) children were more likely to report 'asthma ever'. Children with diabetes (AOR 9.35 (95% CI 3.11, 28.12, P < 0.001)) and attention deficit (AOR 3.39 (95% CI 2.04, 5.64), P < 0.001) were more likely to report 'current asthma'.

CONCLUSIONS

The pattern of association with co-morbidities was different for asthma and obesity. The temporal decline/plateau effect in 'current asthma' could not be explained by concurrent body mass index changes. The decline in obesity was largely driven by the 2005 findings. Longer term trends need to be evaluated further.

Maternal microchimerism protects against the development of asthma

BACKGROUND

Maternal asthma and child's sex are among the most significant and reproducible risk factors for the development of asthma. Although the mechanisms for these effects are unknown, they likely involve nonclassical genetic mechanisms. One such mechanism could involve the transfer and persistence of maternal cells to her offspring, a common occurrence known as maternal microchimerism (MMc). MMc has been associated with many autoimmune diseases but has not been investigated for a role in asthma or allergic disease.

OBJECTIVE

We hypothesized that some of the observed risks for asthma may be due to different rates of transmission or persistence of maternal cells to children of mothers with asthma compared with children of mothers without asthma, or to sons compared with daughters. We further hypothesized that rates of MMc differ between children with and without asthma.

METHODS

We tested these hypotheses in 317 subjects from 3 independent cohorts by using a real-time quantitative PCR assay to detect a noninherited HLA allele in the child.

RESULTS

MMc was detected in 20.5% of the subjects (range 16.8%-27.1% in the 3 cohorts). We observed lower rates of asthma among MMc-positive subjects than among MMc-negative subjects (odds ratio, 0.38; 95% CI, 0.19-0.79; P = .029). Neither maternal asthma nor sex of the child was a significant predictor of MMc in the child (P = .81 and .15, respectively).

CONCLUSIONS

Our results suggest for the first time that MMc may protect against the development of asthma.

Decreased prevalence of atopic features in patients with psoriatic arthritis, but not in psoriasis vulgaris

BACKGROUND

The prevalence of atopic disorders is reduced in patients with various autoinflammatory diseases but, to our knowledge, this association has not been studied in psoriasis vulgaris or psoriatic arthritis (PSA).

OBJECTIVE

Prevalence of hay fever, asthma, and sensitization to common aeroallergens was compared in patients with psoriasis vulgaris to patients with PSA and control subjects; we also investigated whether atopy influences the arthritis activity and severity scores in patients with PSA.

METHODS

In a cross-sectional cohort study design, the differences in patient-reported lifetime prevalence of atopic disorders and serum IgE directed against common aeroallergens were compared. The effect of atopy on arthritis severity was assessed using the 28-joint Disease Activity Score and Health Assessment Questionnaire. Logistic regression models were used to calculate crude and adjusted odds ratios with 95% confidence intervals (CI) for presence of atopy.

RESULTS

A total of 168 patients with PSA, 133 patients with psoriasis vulgaris, and 147 control subjects were included. The lifetime prevalence of hay fever did not differ across groups. Patients with PSA were less likely to have had asthma than control subjects (adjusted odds ratio 0.20; 95% CI 0.04-0.92) and they were less likely to be sensitized (adjusted odds ratio 0.50; 95% CI 0.25-0.99). Health Assessment Questionnaire-visual analog scales for pain and for patient global score were significantly reduced by sensitization to common aeroallergens (beta-coefficients -0.54 [95% CI -0.84 to -0.25] and -18.4 [95% CI -28.5 to -8.25], respectively.)

LIMITATIONS

This was a cross-sectional, small-numbered study.

CONCLUSION

Atopy may protect against development of PSA and diminish its severity.