Atopic disorders and risk of childhood-onset type 1 diabetes in individuals

Interplay between diabetes mellitus and atopic dermatitis

Inflammatory dermatoses such as atopic dermatitis (AD) have long been linked to the pathogenesis of diabetes mellitus. Indeed, numerous studies show an increased risk of diabetes mellitus in individuals with AD although lower prevalence of diabetes mellitus is also observed in few studies. Though the underlying mechanisms accounting for the reciprocal influence between these two conditions are still unclear, the complex interplay between diabetes mellitus and AD is attributable, in part, to genetic and environmental factors, cytokines, epidermal dysfunction, as well as drugs used for the treatment of AD. Proper management of one condition can mitigate the other condition. In this review, we summarize the evidence of the interaction between diabetes mellitus and AD, and discuss the possible underlying mechanisms by which these two conditions influence each other.

Allergy and autoimmunity in children: non-mutually exclusive diseases. A narrative review

In last decades a simultaneous increase in the prevalence of atopic and autoimmune disorders in pediatric population has been observed. Despite the Th1-Th2 paradigm, supporting the polarization of the immune system with Th1 response involved in autoimmune diseases and Th2 response leading to hypersensitivity reactions, recent evidence suggests a possible coexistence of common pathogenic pathways as result of shared immune dysregulation. Similar genes and other mechanisms such as epithelial barrier damage, gut microbiota dysbiosis and reduced number of T regs and IL-10 contribute to the onset of allergy and autoimmunity. IgA deficiency is also hypothesized to be the crosslink between celiac disease and allergy by lowering gut mucous membrane protection from antigens and allergens. The present narrative review aims to give an overview of the co-occurrence of allergic and autoimmune disorders (celiac disease, inflammatory bowel diseases, type 1 diabetes mellitus, thyroid disease, juvenile idiopathic arthritis) in pediatric population, based on the available evidence. We also highlighted the common pathogenic pathways that may underpin both. Our findings confirm that allergic and autoimmune diseases are commonly associated, and clinicians should therefore be aware of the possible coexistence of these conditions in order to ameliorate disease management and patient care. Particular attention should be paid to the association between atopic dermatitis or asthma and celiac disease or type 1 diabetes and vice versa, for therapeutic interventions. Further studies are needed to better clarify mechanisms involved in the pathogenesis and eventually identify new therapeutic strategies.

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.

Involvement of Atopic Dermatitis in the Development of Systemic Inflammatory Diseases

The skin is recognized as a peripheral lymphoid organ that plays an essential defensive action against external environmental stimuli. However, continuous stimulation of these factors causes chronic inflammation at the local site and occasionally causes tissue damage. Chronic inflammation is recognized as a trigger for systemic organ inflammation. Atopic dermatitis (AD) is a chronic inflammatory skin disease that is influenced by various external environmental factors, such as dry conditions, chemical exposure, and microorganisms. The pathogenesis of AD involves various Th2 and proinflammatory cytokines. Recently updated studies have shown that atopic skin-derived cytokines influence systemic organ function and oncogenesis. In this review, we focus on AD’s influence on the development of systemic inflammatory diseases and malignancies.

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.

Type 1 diabetes and asthma: a systematic review and meta-analysis of observational studies

PURPOSE

Type 1 diabetes (T1D) and asthma are both the top concurrent non-communicable diseases in the world, and the existence of a relationship between the two is an area of debate.

METHODS

All eligible observational studies in PubMed and EMBASE databases from inception to August 2021 were searched for data extraction and analysis. The pooled odds ratio (OR) with corresponding 95% confidence intervals (95% CI) was evaluated using fixed-effects or random-effects models in RevMan 5.3, and I² and Cochran Q tests were used to assess the heterogeneity.

RESULTS

22 studies with 25,578 T1D and 3,330,901 non-T1D were included in this meta-analysis. After data analysis, there seems to be no apparent connectivity between asthma and T1D as the crude OR (cOR) was 1.07 (95%CI, 0.93-1.23). Nevertheless, after limiting the meta-analysis to 6 studies with adjusted OR (aOR) available, the results suggested a positive association between T1D and asthma (aOR, 1.15; 95%CI, 1.06-1.25). Corresponding with this, a meta-analysis of cohort studies also found a positive association between T1D and asthma with the pooled cOR of 1.27 (95% CI, 1.09-1.49) and aOR of 1.15 (95%CI, 1.05-1.26). Further analysis of 7 studies in which the diagnosis of asthma precedes T1D onset revealed that asthma patients are at increased risk of subsequent T1D with the pooled cOR of 1.23 (95%CI, 1.04-1.44) and aOR of 1.58 (95% CI, 1.11-2.24).

CONCLUSION

Our meta-analysis suggests a possible association between T1D and asthma, and patients who were previously diagnosed with asthma carried higher odds of developing T1D.

Metabolic and inflammatory biomarkers in children with atopic dermatitis (AD): a case-control study

Background

Atopic dermatitis is characterized by impaired skin barrier and altered cutaneous innate immunity. The estimated prevalence among Egyptian children was 10–12%. Several studies suggest that it may be associated with systemic comorbidities other than the spectrum of atopy, such as metabolic syndrome and other inflammatory conditions. The aim of this study is to compare the profile of systemic conditions of diabetes, dyslipidemia, and multiple inflammatory markers in children with and without diagnosed atopic dermatitis.

Methods

One hundred atopic dermatitis patients and 101 normal controls were collected from outpatient clinic based on their clinical condition, both had measurement of body mass index, blood sugar, serum insulin, lipid profile, C reactive protein, and gamma-glutamyl transferase.

Results

Children diagnosed with atopic dermatitis had significantly higher levels of body mass index (34.7 ± 5.7 vs 26.1 ± 4.9), fasting glucose (143.2 ± 30.3 vs 100.8 ± 16.0), serum insulin (11.3 ± 4.4 vs. 4.6 ± 3.0), serum triglycerides (194.1 ± 38.1 vs 156.2 ± 31.6), total cholesterol (198.4 ± 27.7 vs 163.7 ± 27.7), alkaline phosphatase (229.4 ± 89.8 vs. 189.4 ± 46.8), and gamma-glutamyl transferase (54.7 ± 19.9 vs 34.3 ± 9.5), C-reactive protein level was approximately four times higher (19.9 ± 13.2 vs 5.1 ± 3.4) and the immunoglobulin E level was approximately 10 times higher (2050.3 ± 843.8 vs 252.7 ± 103.1) than in controls

Conclusion

We found a positive relationship of atopic dermatitis with both diabetes and hyperlipidemia among children, and positive dose-response relationship of several non-traditional biomarkers of C-reactive protein, gamma-glutamyl transferase, and alkaline phosphatase with the presence and severity of atopic dermatitis.

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 Cross-Talk Between Atopic Dermatitis and Diabetes Mellitus: A Meta-Analysis

INTRODUCTION

Atopic dermatitis (AD) is associated with various systemic diseases. However, its association with diabetes mellitus (DM) was discussed controversially. Few researchers reviewed the association of these two common morbid disorders. This meta-analysis aimed to assess the relationship between AD and DM.

METHODS

We systematically searched PubMed including Epub and ahead of print (198 articles identified) and Cochrane (13 articles) databases. The searching engine was set to include case-control, prospective and retrospective cohorts, and cross-sectional studies from the first published up to February 12, 2021. Two hundred and eleven were identified, eighteen full texts were screened; of them, six were included in the final meta-analysis. The keywords used were AD, diabetes mellitus, type 1 diabetes, and type 2 diabetes. A datasheet was used to record the author's name, year of publication, country and type of the studies, number of events, and total number in the two arms (patients and controls).

RESULTS

Out of the 211 references identified, six studies were pooled to test the association between diabetes mellitus and AD. The studies showed that AD is lower among patients with DM, odds ratio, 0.69, 95% CI, and 0.67-0.72. No heterogeneity was observed (Chi-Square, 4.12, degree of freedom (df.)= 5, and I² = 0%, P-value), 0.53 and P-value for overall effect, <0.001. The included studies were published in Europe (five) and Canada (one study) and included 162,882 patients and 12,164 events, four of the studied articles were case-control studies, one retrospective, and one cross-sectional.

CONCLUSION

AD was lower among patients with DM compared to their counterparts without the disease. Further studies focusing on the genetic and environmental factors linking AD and diabetes are needed.

The Association Between High Birth Weight and Long-Term Outcomes-Implications for Assisted Reproductive Technologies: A Systematic Review and Meta-Analysis

Background: Studies have shown that the prevalence of children born with high birth weight or large for gestational age (LGA) is increasing. This is true for spontaneous pregnancies; however, children born after frozen embryo transfer (FET) as part of assisted reproductive technology (ART) also have an elevated risk. In recent years, the practice of FET has increased rapidly and while the perinatal and obstetric risks are well-studied, less is known about the long-term health consequences. Objective: The aim of this systematic review was to describe the association between high birth weight and LGA on long-term child outcomes. Data Sources: PubMed, Scopus, and Web of Science were searched up to January 2021. Exposure included high birth weight and LGA. Long-term outcome variables included malignancies, psychiatric disorders, cardiovascular disease, and diabetes. Study Selection: Original studies published in English or Scandinavian languages were included. Studies with a control group were included while studies published as abstracts and case reports were excluded. Data Extraction: The methodological quality, in terms of risk of bias, was assessed by pairs of reviewers. Robins-I (www.methods.cochrane.org) was used for risk of bias assessment in original articles. For systematic reviews, AMSTAR (www.amstar.ca) was used. For certainty of evidence, we used the GRADE system. The systematic review followed PRISMA guidelines. When possible, meta-analyses were performed. Results: The search included 11,767 articles out of which 173 met the inclusion criteria and were included in the qualitative analysis, while 63 were included in quantitative synthesis (meta-analyses). High birth weight and/or LGA was associated with low to moderately elevated risks for certain malignancies in childhood, breast cancer, several psychiatric disorders, hypertension in childhood, and type 1 and 2 diabetes. Conclusions: Although the increased risks for adverse outcome in offspring associated with high birth weight and LGA represent serious health effects in childhood and in adulthood, the size of these effects seems moderate. The identified risk association should, however, be taken into account in decisions concerning fresh and frozen ART cycles and is of general importance in view of the increasing prevalence in high birthweight babies.

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.

Pre-pregnancy body mass index in mothers, birth weight and the risk of type I diabetes in their offspring: A dose-response meta-analysis of cohort studies

BACKGROUND

The incidence of type I diabetes among children has increased significantly and the relationship between maternal pre-pregnancy Body Mass Index (BMI), Birth weight and risk of Type 1 diabetes in children (T1DMC) is controversial.

OBJECTIVE

This dose-response meta-analysis was performed to investigate the association between maternal Pre-Pregnancy Body-Mass Index, Birth Weight and the Risk of Childhood Type I Diabetes.

SEARCH STRATEGY

A comprehensive systematic search was conducted in MEDLINE/PubMed, SCOPUS, Cochrane, and Web of Science databases from inception to April 2019. Key search terms included "body mass index" OR "Birth weight" AND "Type 1 diabetes".

SELECTION CRITERIA

Peer-reviewed studies that reporting association between BMI or birth weight and type I diabetes in a retrospective or prospective study by appropriate estimates such as the hazard ratio (HR), risk ratio (RR), or odds ratio (OR) and the corresponding 95 % confidence intervals (CI).

DATA COLLECTION AND ANALYSIS

MOOSE guidelines were followed. Data were extracted by 2 researchers, independently. Combined hazard ratios (HRs) was evaluated by DerSimonian and Laird Random-effects model.

RESULTS

Two studies continuing four arms with 1,209,122 participants were eligible for pre-pregnancy BMI section meta-analysis and six studies were eligible for inclusion, providing 10,340,036 participants for birth weight section meta-analysis. Pooled results demonstrated a significant association between obesity and risk of T1DMC (HR: 1.30, 95 % CI: 1.16-1.46, I2 = 7%). The combined HR (95 % CI) showed lower risk of T1DMC in low birth weight infants (HR: 0.78, 95 % CI: 0.69-0.88, I2 = 0%) and higher risk of T1DMC in the high birth weight infants versus the normal category of birth weight (HR: 1.08, 95 % CI: 1.00-1.17, I2 = 31 %). There was a significant non-linear association between birth weight and risk of T1DMC in children (Coef =-0.00032, p = 0.001).

CONCLUSIONS AND RELEVANCE

This systematic review and meta-analysis identified high maternal BMI and High birth weight (HBW) increase risk of childhood T1DMC.

Prevalence of early and late prematurity is similar among pediatric type 1 diabetes patients and the general population

BACKGROUND

The incidence of type 1 diabetes mellitus (T1DM) has increased in recent decades, as has the incidence of preterm births (<37 weeks). We aimed to evaluate and compare the prevalence of prematurity and early prematurity (<34 weeks) and birth season variability among T1DM and non-T1DM children.

METHODS

A nationwide cross-sectional study was conducted, with linkage of data from 13 paediatric diabetes centers and Israeli National Registries, including T1DM patients and general non-T1DM population, born during 2000 to 2013. Gathered data included ethnicity, gender, birth week, weight, and season. The prevalence of prematurity and birth season were compared with the general population birth registry using Pearson Chi-square test.

RESULTS

The study population included 1452 T1DM patients, 52.7% males, and 2 138 668 subjects in the general non-T1DM population, 51.2% males. The prevalence of late and early prematurity was similar between groups (6.1% and 2.2% in the T1DM group vs 5.6% and 2.0% in the general non-T1DM group, P = 0.25 and P = 0.38, respectively). OR for prematurity among T1DM patients was 1.15 (0.95-1.39), P = 0.16. No difference in birth season was demonstrated between preterm and term, in T1DM and general non-T1DM populations. Ethiopian descent was more prevalent among T1DM patients compared with the non-T1DM population, in both term and preterm born.

CONCLUSIONS

This is the largest population-based study, and the first in the Middle East geographical area, indicating that prematurity, including early prematurity, is not associated with T1DM during childhood. The study was registered at https://clinicaltrials.gov/: NCT02929953.

Chromosome 17q21 Genes ORMDL3 and GSDMB in Asthma and Immune Diseases

Chromosome 17q21 contains a cluster of genes including ORMDL3 and GSDMB, which have been highly linked to asthma in genome-wide association studies. ORMDL3 is localized to the endoplasmic reticulum and regulates downstream pathways including sphingolipids, metalloproteases, remodeling genes, and chemokines. ORMDL3 inhibits serine palmitoyl-CoA transferase, the rate-limiting enzyme for sphingolipid biosynthesis. In addition, ORMDL3 activates the ATF6α branch of the unfolded protein response which regulates SERCA2b and IL-6, pathways of potential importance to asthma. The SNP-linking chromosome 17q21 to asthma is associated with increased ORMDL3 and GSDMB expression. Mice expressing either increased levels of human ORMDL3, or human GSDMB, have an asthma phenotype characterized by increased airway responsiveness and increased airway remodeling (increased smooth muscle and fibrosis) in the absence of airway inflammation. GSDMB regulates expression of 5-LO and TGF-β1 which are known pathways involved in the pathogenesis of asthma. GSDMB is one of four members of the GSDM family (GSDMA, GSDMB, GSDMC, and GSDMD). GSDMD (located on chromosome 8q24 and not linked to asthma) has emerged as a key mediator of pyroptosis. GSDMD is a key component of the NLPR3 inflammasome and is required for its activation. GSDMD undergoes proteolytic cleavage by caspase-1 to release its N-terminal fragment, which in turn mediates pyroptosis and IL-1β secretion. Chromosome 17q21 has not only been linked to asthma but also to type 1 diabetes, inflammatory bowel disease, and primary biliary cirrhosis suggesting that future insights into the biology of genes located in this region will increase our understanding of these diseases.

Planned Repeat Cesarean Section at Term and Adverse Childhood Health Outcomes: A Record-Linkage Study

BACKGROUND

Global cesarean section (CS) rates range from 1% to 52%, with a previous CS being the commonest indication. Labour following a previous CS carries risk of scar rupture, with potential for offspring hypoxic brain injury, leading to high rates of repeat elective CS. However, the effect of delivery by CS on long-term outcomes in children is unclear. Increasing evidence suggests that in avoiding exposure to maternal bowel flora during labour or vaginal birth, offspring delivered by CS may be adversely affected in terms of energy uptake from the gut and immune development, increasing obesity and asthma risks, respectively. This study aimed to address the evidence gap on long-term childhood outcomes following repeat CS by comparing adverse childhood health outcomes after (1) planned repeat CS and (2) unscheduled repeat CS with those that follow vaginal birth after CS (VBAC).

METHODS AND FINDINGS

A data-linkage cohort study was performed. All second-born, term, singleton offspring delivered between 1 January 1993 and 31 December 2007 in Scotland, UK, to women with a history of CS (n = 40,145) were followed up until 31 January 2015. Outcomes assessed included obesity at age 5 y, hospitalisation with asthma, learning disability, cerebral palsy, and death. Cox regression and binary logistic regression were used as appropriate to compare outcomes following planned repeat CS (n = 17,919) and unscheduled repeat CS (n = 8,847) with those following VBAC (n = 13,379). Risk of hospitalisation with asthma was greater following both unscheduled repeat CS (3.7% versus 3.3%, adjusted hazard ratio [HR] 1.18, 95% CI 1.05-1.33) and planned repeat CS (3.6% versus 3.3%, adjusted HR 1.24, 95% CI 1.09-1.42) compared with VBAC. Learning disability and death were more common following unscheduled repeat CS compared with VBAC (3.7% versus 2.3%, adjusted odds ratio 1.64, 95% CI 1.17-2.29, and 0.5% versus 0.4%, adjusted HR 1.50, 95% CI 1.00-2.25, respectively). Risk of obesity at age 5 y and risk of cerebral palsy were similar between planned repeat CS or unscheduled repeat CS and VBAC. Study limitations include the risk that women undergoing an unscheduled CS had intended to have a planned CS, and lack of data on indication for CS, which may confound the findings.

CONCLUSIONS

Birth by repeat CS, whether planned or unscheduled, was associated with an increased risk of hospitalisation with asthma but no difference in risk of obesity at age 5 y. Greater risk of death and learning disability following unscheduled repeat CS compared to VBAC may reflect complications during labour. Further research, including meta-analyses of studies of rarer outcomes (e.g., cerebral palsy), are needed to confirm whether such risks are similar between delivery groups.

Clustering of autoimmune diseases in patients with rosacea

BACKGROUND

Rosacea is a common inflammatory skin condition that shares genetic risk loci with autoimmune diseases such as type 1 diabetes mellitus (T1DM) and celiac disease. A recent genomewide association study identified 90 genetic regions associated with T1DM, celiac disease, multiple sclerosis, and/or rheumatoid arthritis, respectively. However, a possible association with rosacea was not investigated.

OBJECTIVE

We evaluated the association between rosacea and T1DM, celiac disease, multiple sclerosis, and rheumatoid arthritis, respectively.

METHODS

We performed a population-based case-control study. A total of 6759 patients with rosacea were identified and matched with 33,795 control subjects on age, sex, and calendar time. We used conditional logistic regression to calculate crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

After adjustment for smoking and socioeconomic status, patients with rosacea had significantly increased ORs for T1DM (OR 2.59, 95% CI 1.41-4.73), celiac disease (OR 2.03, 95% CI 1.35-3.07), multiple sclerosis (OR 1.65, 95% CI 1.20-2.28), and rheumatoid arthritis (OR 2.14, 95% CI 1.82-2.52). The association was mainly observed in women.

LIMITATIONS

We were unable to distinguish between the different subtypes and severities of rosacea.

CONCLUSIONS

Rosacea is associated with T1DM, celiac disease, multiple sclerosis, and rheumatoid arthritis, respectively, in women, whereas the association in men only reached statistical significance for rheumatoid arthritis.

Assessment of vitamin D levels in newly diagnosed children with type 1 diabetes mellitus comparing two methods of measurement: a facility's experience in the Middle Eastern country of Bahrain

BACKGROUND

The number of children being diagnosed with type 1 diabetes mellitus (T1DM) is on the rise and has more than doubled in the past 10 years in Bahrain. Some studies have linked low vitamin D levels with an increased risk of diabetes. There are concerns regarding the variations in circulating 25(OH)D levels measured by different laboratories and by using different analytical techniques.

OBJECTIVE

The aim of this study was to evaluate the vitamin D levels of newly diagnosed children with T1DM using the "gold standard method" with high-pressure liquid chromatography-tandem mass spectrometry methods compared to the chemiluminescence micro-particle immunoassay (CMIA) used in a hospital laboratory.

SUBJECTS

Eighteen children, aged 6-12 years, who received a confirmed diagnosis of T1DM in 2014 were chosen as subjects.

METHODS

Serum vitamin D levels were assessed in a hospital, while an extra aliquot of blood collected during routine blood collection after acquiring informed written consents from the subjects, and sent to Princess Al-Jawhara Center for Molecular Medicine and Inherited Disorders to be analyzed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

RESULTS

The mean age of the study group was 9±2 years. The mean total of 25(OH)D levels (D3 and D2) assessed by UPLC-MS/MS was 49.7±18.8, whereas the mean total of 25(OH)D levels obtained from the CMIA assay was 44.60±13.20. The difference in classification between the two methods was found to be statistically significant (P=0.004). A Bland-Altman plot showed a poor level of agreement between the two assay methods. The CMIA overestimated insufficient values and underestimated deficiency, when compared to UPLC-MS/MS.

CONCLUSION

There was a statistically significant difference between the two assay methods with CMIA overestimating vitamin D insufficiency. Clinicians should be prudent in their assessment of a single vitamin D reading, when the gold standard method is not available or feasible.

Association between IgE-mediated allergies and diabetes mellitus type 1 in children and adolescents

BACKGROUND

Type 1 diabetes mellitus (T1DM) is characterized by an immunological reaction that is dominated by type-1 T helper (Th1) cells, whereas immunoglobulin E (IgE)-mediated allergies are associated with Th2 cell. According to the Th1/Th2-hypothesis, the immune system is said to either develop into the direction of Th1 or Th2 cells. This would mean that a child developing T1DM is unlikely to develop an IgE-mediated allergy and vice versa.

OBJECTIVE

The aim of the study was to investigate the association between the prevalence of T1DM and IgE-mediated allergies.

METHODS

We designed a prospective case control study with 94 children and adolescents with T1DM and 188 age- and sex-matched control children. The basis of our investigations was a questionnaire concerning the family and children's history as to the presence of IgE-mediated allergies. Moreover, the following blood investigations were done: total serum IgE, specific IgE antibodies to major inhalant allergens, and a multiplex cytokine analysis measuring levels of specific cytokines representing either Th1- or Th2- cytokines.

RESULTS

Children with T1DM reported the presence of IgE-mediated allergies significantly more often than children of the control group. Children with T1DM had significantly higher tumor necrosis factor alpha (TNFα) levels than healthy controls. Levels of interleukin-2 (IL-2) and IL-6 were higher in the groups of children with the presence of a personal history of allergies, regardless of the presence of T1DM.

CONCLUSIONS

Our results suggest that T1DM is associated with a higher risk of a self-reported presence of IgE-mediated allergies and that the Th1/Th2-hypothesis may be an oversimplification.

Preterm birth and risk of type 1 and type 2 diabetes: systematic review and meta-analysis

Preterm birth is suggested to play an important role in the development of diabetes. However, results have been inconsistent. We conducted a systematic review and meta-analysis to clarify the relationship between preterm birth and type 1 and type 2 diabetes. PubMed, Embase and ISI Web of Science were searched. A total of 18 studies (including 2,176,480 participants and 22,073 cases) for type 1 diabetes and five studies (including 31,478 participants and 1,898 cases) for type 2 diabetes were included in the current meta-analyses. We calculated pooled odds ratio (OR) and 95% confidence interval (CI) using fixed-effects model to evaluate the relations between preterm birth and type 1 and type 2 diabetes. The results suggested that preterm birth was significantly associated with increased risk of type 1 diabetes (OR = 1.18, 95% CI = 1.11-1.25), with no evidence of between-study heterogeneity (I(2) = 13.2%, P = 0.296). Preterm birth was also significantly associated with increased risk of type 2 diabetes (OR = 1.51, 95% CI = 1.32-1.72), with no evidence of (I(2) = 0.0%, P = 0.557). Subgroup analyses suggested that there was significant association in both case-control studies (OR = 1.16, 95% CI = 1.06-1.26) and cohort studies (relative risk = 1.20, 95% CI = 1.11-1.29) for type 1 diabetes, and similar results were found for type 2 diabetes. The results suggested that preterm birth was a significant and independent risk factor for both type 1 and type 2 diabetes.

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 dietary fat and fatty acid intake during lactation and the risk of asthma in the offspring

AIM

To explore the association between maternal dietary fat and fatty acid (FA) intake during lactation, and the risk of asthma in the offspring by the age of 5 years.

METHODS

The subjects comprised 1798 mother-child pairs from the Type 1 Diabetes Prediction and Prevention (DIPP) Nutrition Study. Dietary intake was assessed by a validated 181-item food frequency questionnaire, which covered the third month of lactation. The cumulative incidence of asthma was assessed at the age of 5 years with a questionnaire modified from the International Study of Asthma and Allergies in Childhood (ISAAC). Cox proportional hazards regression was used for statistical analysis.

RESULTS

The maternal use of margarines during lactation was associated with a marginally increased risk of asthma [hazard ratio (HR) for user vs. nonuser 1.96, 95% confidence interval (CI) 1.01-3.82, p = 0.047] after adjusting for putative confounders. The maternal intakes of n-3 polyunsaturated FA (PUFA) and fish during lactation were not associated with the risk of asthma.

CONCLUSION

Maternal use of margarines during lactation was weakly associated with an increased risk of asthma in the offspring at the age of 5 years. Other fats or FAs during lactation were not associated with the risk of asthma. However, the nonadherence to dietary recommendations regarding especially fats of our study population may restrict the generalizability of our results.

Risk Factors for Type 1 Diabetes Mellitus among Children and Adolescents in Basrah

OBJECTIVES

Environmental factors play an important role in the pathogenesis of type 1 diabetes mellitus, many of these factors have been uncovered despite much research. A case-control study was carried out to determine the potential maternal, neonatal and early childhood risk factors for type 1 diabetes mellitus in children and adolescents in Basrah.

METHODS

A total of 96 diabetic patients who have been admitted to the pediatric wards at 3 main hospitals in Basrah, and those who have visited primary health care centers over the period from the 4(th) of November 2006 to the end of May 2007 were recruited. In addition, 299 non-diabetic children were included, their age ranged from 18 months to 17 years.

RESULTS

Family history of type 1 diabetes mellitus and thyroid diseases in first and second degree relatives was found to be an independent risk factor for type 1 diabetes mellitus, (p<0.001). Regarding maternal habits and illnesses during pregnancy, the study has revealed that tea drinking during pregnancy is a risk factor for type 1 diabetes mellitus in their offspring, (p<0.05). In addition, maternal pre-eclampsia and infections were found to be significant risk factor for type 1 diabetes mellitus, (p<0.001). Neonatal infections, eczema and rhinitis during infancy were also significantly associated with development of type 1 diabetes mellitus. Moreover, the results revealed that duration of <6 months breast feeding is an important trigger of type 1 diabetes mellitus.

CONCLUSION

Exposure to environmental risk factors during pregnancy (tea drinking, pre-eclampsia, and infectious diseases), neonatal period (respiratory distress, jaundice and infections) and early infancy are thought to play an important role in triggering the immune process leading to B-cell destruction and the development of type 1 diabetes mellitus.

Maternal intake of fatty acids during pregnancy and allergies in the offspring

Fatty acids (FA) are known to have a number of immunological effects and, accordingly, may play a role in the development of allergic diseases. We investigated the effect of maternal intake of FA during pregnancy on the risk of allergic rhinitis, wheeze and atopic eczema in children aged 5 years. The present study analysed data from the Finnish Type 1 Diabetes Prediction and Prevention Nutrition Study, a population-based birth cohort study with a 5-year follow-up. Complete information on maternal diet (assessed by a validated FFQ) and International Study of Asthma and Allergies in Childhood-based allergic outcomes was available for 2441 children. Cox proportional regression and logistic regression were used for the analyses. After adjusting for potential confounding variables, high maternal consumption of butter and butter spreads (hazard ratio (HR) 1.33; 95 % CI 1.03, 1.71) and higher ratio of n-6:n-3 FA (HR 1.37; 95 % CI 1.07, 1.77) during pregnancy were associated with an increased risk of allergic rhinitis in the offspring by 5 years of age. High maternal intakes of total PUFA (HR 0.71; 95 % CI 0.52, 0.96) and α-linolenic FA (HR 0.73; 95 % CI 0.54, 0.98) were associated with a decreased risk of allergic rhinitis. However, these results lost their significance after adjustment for multiple comparisons. Overall, our data suggest that maternal consumption of butter, the ratio of n-6:n-3 FA and intake of PUFA and α-linolenic FA during pregnancy may be potential determinants of allergic rhinitis in the offspring.

Genetic association analyses of atopic illness and proinflammatory cytokine genes with type 1 diabetes

BACKGROUND

The genetic basis of the autoimmune disease type 1 diabetes (T1D) has now been largely determined, so now we can compare these findings with emerging genetic knowledge of disorders and phenotypes that have been negatively or positively associated with T1D historically. Here, we assessed the role in T1D of variants previously reported to be associated with atopic diseases and epithelial barrier function, profilaggrin (FLG), and those that affect the expression levels of the proinflammatory cytokines tumour necrosis factor (TNF)-α, interleukin (IL)-1β, interferon (IFN)γ and IL-18.

METHODS

We genotyped single nucleotide polymorphisms (SNPs): -105/rs28665122 in SELS or SEPS1 (selenoprotein), three single nucleotide polymorphisms in IL18 (-105/rs360717, +183/rs5744292 and +1467/rs574456) and R501X/rs61816761 in FLG, the major locus associated with atopic dermatitis and predisposing to asthma, in a minimum of 6743 T1D cases and 7864 controls.

RESULTS

No evidence of T1D association was found for any of the SNPs we genotyped at FLG, SELS or IL18 (p≥0.03), nor with haplotypes of IL18 (p=0.82). Review of previous T1D genome-wide association results revealed that four (human leucocyte antigen (HLA), gasdermin B/ORM1 (Saccharomyces cerevisiae)-like/gasdermin B/, GSDMB/ORMDL3/GSDMA and IL2RB) of ten loci recently reported to be associated with asthma were associated with T1D (p≤0.005).

CONCLUSIONS

These results show that there are shared genetic associations for atopy-related traits and T1D, and this might help in the future to understand the mechanisms, pathways and environmental factors that underpin the rapid rise in incidence of both disorders in children.

Asthma and allergic symptoms and type 1 diabetes-related autoantibodies in 2.5-yr-old children

A dominance of Th2 cytokine pattern is associated with allergic diseases, whereas a Th1 pattern has been reported in autoimmune type 1 diabetes (T1D). The Th1/Th2 paradigm has led to the interest in the relationship between these diseases. To investigate the association between atopic diseases, asthma and occurrence of T1D-related β-cell autoantibodies in children, we studied 7208 unselected 2.5-yr-old children from the All Babies in Southeast Sweden (ABIS) cohort. The ABIS cohort includes 17 055 (78.3% out of all 21 700) children born from October 1997 to October 1999, and followed prospectively with regular biological samples and questionnaires, at birth, at 1 and 2.5 yr. Risk factors for development of β-cell autoantibodies at the age of 2.5 yr were type of domiciliary, domestic animals (cat and dog) and getting a new brother/sister during first year of life. Maternal smoking during pregnancy [odds ratio (OR) 1.6] and heavy smoking at home (>10 vs. ≤10 cigarettes) implied risk for tyrosine phosphatase autoantibodies (IA-2A) (OR 2.9). Wheezing during the first year of life implied risk for glutamic acid decarboxylase autoantibodies (GADA) (OR 1.9) and double positivity for GADA and IA-2A (OR 9.1). Rash on several locations (at least three times during 12 months) (OR 1.7) as well as allergic symptoms related to fur-bearing animals (OR 2.7) implied risk for IA-2A. Food allergy against egg, cow-milk, fish, nuts/almonds (one or in combination) implied risk for GADA and IA-2A (OR 4.5). In a regression model wheezing during first year of life remained as a risk factor for GADA [OR 2.0, confidence interval (CI) 1.1-3.8; p = 0.031] and both GADA and IA-2A (OR 10.7, CI 3.9-29.4; p = 0.000). We conclude that allergic symptoms are associated with the development of T1D-related autoantibodies during the first years of life.

High levels of immunoglobulin E and a continuous increase in immunoglobulin G and immunoglobulin M by age in children with newly diagnosed type 1 diabetes

The incidence of type 1 diabetes (T1D) is increasing, either because of environmental factors accelerating onset of the disease or because of inducement of autoimmune diabetes in children who previously were at lower risk. High levels of immunoglobulin (Ig), specifically, IgM and IgA, and a low level of IgG were reported in adult patients; however no studies have analyzed the increasing incidence in relation to Ig levels. Our aim was to describe Ig in children newly diagnosed with diabetes and in their healthy siblings. Children with T1D expressed significantly lower IgG (p < 0.01) and higher IgA levels (p = 0.045), whereas no differences in IgE or IgM (p > 0.5) levels were found. Age-specific levels were unchanged over a 9-year period. In patients and siblings IgG, IgA and IgE increased by age (p < 0.001); which was in contrast to IgM (p > 0.05). The continued increase in IgG levels by age indicates that adult levels are reached later than in previously studied cohorts, thereby indicating a slower maturation of the immune system.

A meta-analysis of the association between pre-eclampsia and childhood-onset Type 1 diabetes mellitus

AIMS

To review and synthesize the evidence for an increased risk of childhood Type 1 diabetes mellitus in children born to mothers diagnosed with pre-eclampsia during pregnancy.

METHODS

A comprehensive search of the published literature was performed in MEDLINE, Web of Science and EMBASE limited to studies published before August 2010. Crude odds ratios and 95% confidence intervals were calculated from the data reported in each study. Meta-analysis techniques were then used to derive a combined odds ratio and investigate heterogeneity. Sensitivity analyses were conducted by study design, ascertainment of pre-eclampsia and study quality.

RESULTS

Data were available from 16 studies including 8315 children with Type 1 diabetes. Overall, there was little evidence of an increase in the risk of Type 1 diabetes in children born to mothers who had pre-eclampsia during pregnancy (OR = 1.10, 95% CI 0.96-1.27; P = 0.17). This association did not vary much between studies (I(2) = 28%, P for heterogeneity =0.14). The association was similar in three cohort studies (OR = 1.05, 95% CI 0.77-1.44; P = 0.75) and in seven studies with a low risk of bias (OR = 1.13, 95% CI 0.91-1.40; P = 0.27), but was more marked in 13 studies which ascertained pre-eclampsia from obstetrical records or birth registry data (OR = 1.18, 95% CI 1.03-1.36; P = 0.02).

CONCLUSIONS

This analysis demonstrates little evidence of any substantial increase in childhood Type 1 diabetes risk after pregnancy complicated by pre-eclampsia.

Intake of antioxidants during pregnancy and the risk of allergies and asthma in the offspring

BACKGROUND/OBJECTIVES

The potential immune functions related to the damages induced by oxygen-free radicals suggest that antioxidants may have a role in the development of allergies. The objective was to investigate the association between maternal intake of antioxidants during pregnancy and the risk of asthma, rhinitis and eczema in 5-year-old children.

SUBJECTS/METHODS

This study was on the basis of the Finnish Type 1 Diabetes Prediction and Prevention Nutrition Study, a population-based birth cohort study with 5-year follow-up. Complete information on maternal food frequency questionnaire data and ISAAC (International Study of Asthma and Allergies in Childhood)-based allergic outcomes were available for 2441 children. Cox proportional regression and logistic regression were used for the analyses.

RESULTS

Maternal intake of any of the antioxidants was not significantly associated with the risk of asthma, rhinitis or eczema in the offspring, except for dietary intake of magnesium, which was independently associated with protection against eczema (OR 0.78; 95% CI 0.62-0.97).

CONCLUSION

Maternal intake of dietary magnesium during pregnancy may protect against the risk of eczema in the offspring. We did not confirm previous observations concerning other antioxidants. This may be due to the variable amount of antioxidant intake across studies and also indicative of the hypothesis that there may be a critical time window in pregnancy during which antioxidants might modify the risk of allergies in the offspring.

Correlation of worldwide incidence of type 1 diabetes (DiaMond) with prevalence of asthma and atopic eczema (ISAAC)

INTRODUCTION

Environmental factors play a role in pathogenesis of both type 1 diabetes and atopic disease but they remain incompletely understood. T cell-mediated responses primarily of the T helper type 1 (Th1) are involved in type 1 diabetes while T helper type 2 (Th2) responses favour allergic disease. This TH 1/TH 2 paradigm is currently the source of much controversy in various studies.

OBJECTIVE

The aim of the study was to compare the reported country incidence of type 1 diabetes with the prevalence of atopic disease.

METHODS

The prevalence of wheeze, rhinitis, rhinoconjunctivitis and atopic eczema in the preceding 12 months in the 13- to 14-year-old age group was taken from The International Study of Asthma and Allergies in Childhood phase 1 study. These were compared to the age specific incidence of type 1 diabetes in children per 100 000 per year obtained from the Diabetes Mondiale Project Group study from those countries participating in both studies. Data collected from these 31 countries together with latitude was analysed using a Pearson correlation and significance analysis. A multiple regression analysis determined the confounding effect of latitude.

RESULTS

The incidence of type 1 diabetes was found to have a positive correlation with both wheezing (P = 0.009) and atopic eczema (P < 0.01). There was a no correlation between the incidence of type 1 diabetes and the prevalance of rhinitis (r = 0.02, P = 0.88) or of rhinoconjunctivitis (r = 0.026, P = 0.88). Latitude correlated negatively with type 1 diabetes and positively with rhinitis and rhinoconjnctuvits; it was not significantly correlated with wheeze or eczema. Regression analysis showed that latitude is a significant confounding factor in the correlation of rhinitis (P value < 0.0008) and rhinoconjunctivitis (P value < 0.0003) with diabetes.

CONCLUSIONS

The study suggests that common environmental and/or genetic factors predispose to type 1 diabetes, wheezing and atopic eczema while factors predisposing to rhinitis and rhinoconjunctivitis appear to be distinct from those predisposing to type 1 diabetes.

Does the relative risk for type 1 diabetes conferred by HLA-DQ, INS, and PTPN22 polymorphisms vary with maternal age, birth weight, or cesarean section?

BACKGROUND AND OBJECTIVE

Maternal age at birth, birth weight, and cesarean section has been associated with a weak but significant increase in risk of type 1 diabetes. The objective was to assess whether the relative risk for type 1 diabetes conferred by established susceptibility loci human leukocyte antigen (HLA)-DQ, INS, and PTPN22 differed depending on these perinatal factors.

METHODS

We employed a case-control study with 456 cases of type 1 diabetes diagnosed before 15 yr of age and 1377 population-based control children. HLA genotypes were divided into high to moderate risk (DQ8/DQ2, DQ8/DQ8, DQ8/X, DQ2/DQ2) vs. all other genotypes. Case-only analysis using logistic regression was used to test for significant interaction.

RESULTS

There was no significant difference in the relative risks conferred by HLA-DQ, INS, or PTPN22 by maternal age, birth weight, or mode of delivery, except the relative risk conferred by PTPN22 which was 2.11 [95% confidence interval (CI): 1.64-2.72] for those born vaginally and 0.99 (95% CI: 0.50-1.99) for those born by cesarean section [p(interaction) = 0.028].

CONCLUSION

The relative risks conferred by the three established susceptibility genes investigated here were independent of the perinatal factors, apart from a possible interaction between PTPN22 and mode of delivery.

Association between allergies and multiple sclerosis: a systematic review and meta-analysis

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system that expresses a typical type 1 immune response (Th1). Allergies, on the other hand, present with high levels of type 2 (Th2) cytokines. Some authors observed that Th1 and Th2 diseases could coexist in the same subject. Besides its biological plausibility, the association between MS and allergies remains controversial. The aim of this systematic review and meta-analysis was to determine if there is an association between allergic diseases and MS. All clinical and epidemiological studies on patients with MS published up to July 2009, that assessed the association between allergic diseases and MS were reviewed. A total of 1010 articles were retrieved from search, and ten epidemiological studies were included in the analysis. The results showed that there is no evidence supporting an association between allergic diseases (OR: 0.91; CI 95%: 0.68-1.23), asthma (OR: 0.83; CI 95%: 0.48-1.44), allergic rhinitis (OR: 0.81; CI 95%: 0.59-1.12), eczema (OR: 0.93; CI 95%: 0.71-1.23) and MS. Additional prospective studies in this field might help to elucidate the nature of these associations.

An inverse association between history of childhood eczema and subsequent risk of type 1 diabetes that is not likely to be explained by HLA-DQ, PTPN22, or CTLA4 polymorphisms

BACKGROUND

Established genetic susceptibility loci for type 1 diabetes are important in immune regulation and may play a role also in atopic disorders, potentially explaining the inverse association between childhood eczema and subsequent risk for type 1 diabetes previously reported.

OBJECTIVE

We aimed to directly assess whether HLA-DQ, CTLA4, and PTPN22 genes could explain the putative association between childhood eczema and lower subsequent risk of type 1 diabetes observed in several case-control studies.

METHODS

We designed a case-control study with 339 incident cases of type 1 diabetes identified in the Norwegian childhood diabetes registry, and 985 population-based control children. DNA was collected, and physician-diagnosed childhood eczema was ascertained by a questionnaire administered to the parents of children with and without type 1 diabetes.

RESULTS

The previously reported association between childhood eczema and lower risk of type 1 diabetes was confirmed (odds ratio,OR, 0.61, 95% confidence interval, CI, 0.40-0.95] and this was consistent in subgroups defined by HLA-DQ, CTLA4, and PTPN22 genotypes. The OR was essentially not influenced by adjustment for genetic variation at these loci (OR simultaneously adjusted for the three genetic loci: 0.55, 95% CI: 0.32-0.92). The ratio of the unadjusted to adjusted OR was 1.12, with a corresponding 95% CI from 0.84 to 1.50.

CONCLUSION

In this first study of its kind, we demonstrated directly that the observed inverse association between childhood eczema and type 1 diabetes is not likely to be explained by the established diabetes susceptibility genes HLA-DQ, CTLA4, or PTPN22.

Co-occurrence of allergic sensitization and type 1 diabetes

BACKGROUND

The mechanisms leading to abnormal immune regulation in type 1 diabetes and allergic diseases may be partly overlapping. If so, these diseases should co-occur more often than expected. We investigated this phenomenon in two contrasting socio-economic environments, Finland and Russian Karelia.

METHODS

We screened 413 Finnish children (of whom 147 had type 1 diabetes) and 244 Russian Karelian children (132 had type 1 diabetes) for total immunoglobulin E (IgE) levels and specific IgE against birch, cat, and egg albumen. In addition we analysed diabetes-related human leukocyte antigen (HLA) haplotypes and antibodies against hepatitis A virus (HAV) and recorded allergic diseases by a questionnaire in Russian Karelia.

RESULTS

In Russian Karelia 15% of the patients with type 1 diabetes, but only 4% of the control subjects had allergen-specific IgE (P = 0.012). A similar difference was observed in the frequency of allergic symptoms. Co-occurrence of allergic sensitization and type 1 diabetes was associated with lack of HAV antibodies and was not seen in Finland where infections are less frequent than in Karelia.

CONCLUSION

Our findings support the idea of common mechanisms in the pathogenesis of allergic diseases and type 1 diabetes, which may be particularly important in an environment with low penetrance of these diseases.

Birthweight and the risk of childhood-onset type 1 diabetes: a meta-analysis of observational studies using individual patient data

AIMS/HYPOTHESIS

We investigated whether children who are heavier at birth have an increased risk of type 1 diabetes.

METHODS

Relevant studies published before February 2009 were identified from literature searches using MEDLINE, Web of Science and EMBASE. Authors of all studies containing relevant data were contacted and asked to provide individual patient data or conduct pre-specified analyses. Risk estimates of type 1 diabetes by category of birthweight were calculated for each study, before and after adjustment for potential confounders.Meta-analysis techniques were then used to derive combined ORs and investigate heterogeneity between studies.

RESULTS

Data were available for 29 predominantly European studies (five cohort, 24 case-control studies), including 12,807 cases of type 1 diabetes. Overall, studies consistently demonstrated that children with birthweight from 3.5 to 4 kg had an increased risk of diabetes of 6% (OR 1.06 [95% CI 1.01-1.11]; p=0.02) and children with birthweight over 4 kg had an increased risk of 10% (OR 1.10 [95% CI 1.04-1.19]; p=0.003), compared with children weighing 3.0 to 3.5 kg at birth. This corresponded to a linear increase in diabetes risk of 3% per 500 g increase in birthweight (OR 1.03 [95% CI 1.00-1.06]; p=0.03). Adjustments for potential confounders such as gestational age, maternal age, birth order, Caesarean section, breastfeeding and maternal diabetes had little effect on these findings.

CONCLUSIONS/INTERPRETATION

Children who are heavier at birth have a significant and consistent, but relatively small increase in risk of type 1 diabetes.

Maternal age at birth and childhood type 1 diabetes: a pooled analysis of 30 observational studies

OBJECTIVE

The aim if the study was to investigate whether children born to older mothers have an increased risk of type 1 diabetes by performing a pooled analysis of previous studies using individual patient data to adjust for recognized confounders.

RESEARCH DESIGN AND METHODS

Relevant studies published before June 2009 were identified from MEDLINE, Web of Science, and EMBASE. Authors of studies were contacted and asked to provide individual patient data or conduct prespecified analyses. Risk estimates of type 1 diabetes by maternal age were calculated for each study, before and after adjustment for potential confounders. Meta-analysis techniques were used to derive combined odds ratios and to investigate heterogeneity among studies.

RESULTS

Data were available for 5 cohort and 25 case-control studies, including 14,724 cases of type 1 diabetes. Overall, there was, on average, a 5% (95% CI 2-9) increase in childhood type 1 diabetes odds per 5-year increase in maternal age (P = 0.006), but there was heterogeneity among studies (heterogeneity I(2) = 70%). In studies with a low risk of bias, there was a more marked increase in diabetes odds of 10% per 5-year increase in maternal age. Adjustments for potential confounders little altered these estimates.

CONCLUSIONS

There was evidence of a weak but significant linear increase in the risk of childhood type 1 diabetes across the range of maternal ages, but the magnitude of association varied between studies. A very small percentage of the increase in the incidence of childhood type 1 diabetes in recent years could be explained by increases in maternal age.

Maternal vitamin D intake during pregnancy is inversely associated with asthma and allergic rhinitis in 5-year-old children

BACKGROUND

Vitamin D is known to have a number of immunological effects and it may play a role in preventing allergic diseases. Objectives To study the effect of maternal intake of vitamin D during pregnancy on the emergence of asthma, allergic rhinitis (AR), and atopic eczema by the age of 5 years in children with HLA-DQB1-conferred susceptibility for type 1 diabetes.

METHODS

Children (1669) participating in the population-based birth cohort study were followed for asthma, AR, and atopic eczema assessed by validated questionnaire at 5 years. Maternal diet was assessed by a food-frequency questionnaire.

RESULTS

The mean maternal intake of vitamin D was 5.1 (SD 2.6) microg from food and 1.4 (2.6) microg from supplements. Only 32% of the women were taking vitamin D supplements. When adjusted for potential confounders, maternal intake of vitamin D from food was negatively related to risk of asthma [hazard ratio (HR) 0.80; 95% confidence interval (CI) 0.64-0.99] and AR [HR 0.85; 95% CI 0.75-0.97]. Vitamin D supplements alone were not associated with any outcome. Adjustment for maternal intake of other dietary factors did not change the results.

CONCLUSION

Maternal vitamin D intake from foods during pregnancy may be negatively associated with risk of asthma and AR in childhood.

Early introduction of oats associated with decreased risk of persistent asthma and early introduction of fish with decreased risk of allergic rhinitis

The evidence of the effect of the age at introduction of new foods during infancy on the development of asthma and allergic rhinitis is inconsistent and scarce. We set out to study these associations. A prospective birth cohort of infants with increased HLA-DQB1-conferred risk for type 1 diabetes was recruited in 1996-2000. The families completed at home a record on the age at introduction of new foods. Persistent asthma and allergic rhinitis were assessed at the age of 5 years with an International Study of Asthma and Allergies in Childhood-type questionnaire. The Cox proportional hazards regression analyses were adjusted for parental asthma and allergic diseases, and several perinatal and sociodemographical factors. Out of the 1293 children, 77 (6.0 %) developed persistent asthma; and out of the 1288 children, 185 (14.4 %) developed allergic rhinitis by the age of 5 years. Early age at introduction of oats was associated with a reduced risk of persistent asthma (hazard ratio (HR; 95 % CI) for the first and mid-tertiles compared with the latest tertile was 0.36 (0.15, 0.85) and 0.37 (0.22, 0.62), respectively, P < 0.001). Early age at introduction of fish was dose dependently associated with a decreased risk of allergic rhinitis (HR (95 % CI) for the first and mid-tertiles compared with the latest tertile was 0.34 (0.22, 0.54) and 0.45 (0.28, 0.70), respectively, P < 0.001). The present finding that age at introduction of oats is inversely and independently associated with development of persistent asthma is novel. We confirmed the earlier observation that the age at introduction of fish is inversely related to the risk of allergic rhinitis. Clinical implications remain to be determined.

Birth weight, early weight gain, and subsequent risk of type 1 diabetes: systematic review and meta-analysis

Previous studies suggest that birth weight and weight gain during the first year of life are related to later risk of type 1 diabetes. The authors performed a systematic review and meta-analysis on these associations. Twelve studies involving 2,398,150 persons of whom 7,491 had type 1 diabetes provided odds ratios and 95% confidence intervals of type 1 diabetes associated with birth weight. Four studies provided data on weight and/or weight gain during the first year of life. High birth weight (>4,000 g) was associated with increased risk of type 1 diabetes (odds ratio = 1.17, 95% confidence interval (CI): 1.09, 1.26). According to sensitivity analysis, this result was not influenced by particular study characteristics. The pooled confounder-adjusted estimate was 1.43 (95% CI: 1.11, 1.85). No heterogeneity was found (I(2) = 0%) and no publication bias. Low birth weight (<2,500 g) was associated with a nonsignificantly decreased risk of type 1 diabetes (odds ratio = 0.82, 95% CI: 0.54, 1.23). Each 1,000-g increase in birth weight was associated with a 7% increase in type 1 diabetes risk. In all studies, patients with type 1 diabetes showed increased weight gain during the first year of life, compared with controls. This meta-analysis indicates that high birth weight and increased early weight gain are risk factors for type 1 diabetes.

[Controversies in the association between type 1 diabetes and asthma]

OBJECTIVE

Critical review of the literature to investigate the relationship between asthma and type 1 diabetes mellitus (DM1).

SOURCE OF DATA

Bibliography search in MEDLINE and LILACS databases in the last twenty years.

SUMMARY OF DATA

Several studies demonstrate an inverse relationship between asthma, atopic diseases and the risk to develop DM1. According to the "Hygiene Hypothesis", the risk of allergic diseases decreases with infections early in childhood, towards distance of Th2 profile, common at birth, to the Th1 phenotype. Other articles described lack of association or positive association between DM1 and allergies. There is a possibility of environmental factors interfering in the development of disorders mediated by Th1 and Th2 cells, in the same individual, due to the absence of immunomodulatory mechanisms mediated by interleukin-10 and regulatory cells.

CONCLUSION

The existing information about the inverse association between Th1-mediated diseases (e.g., DM1), and those that are Th2-mediated (e.g., allergies) are conflicting requiring more investigation to explain this question.

A TLR2 polymorphism is associated with type 1 diabetes and allergic asthma

Type 1 diabetes (T1D) and allergic asthma are immune-mediated diseases. Pattern recognition receptors are proteins expressed by cells in the immune system to identify microbial pathogens and endogenous ligands. Toll-like receptors (TLRs) and CD14 are members of this family and could represent a molecular link between microbial infections and immune-mediated diseases. Diverging hypotheses regarding whether there exists a common or inverse genetic etiology behind these immune-mediated diseases have been presented. We aimed to test whether there exist common or inverse associations between polymorphisms in the pattern recognition receptors TLR2, TLR4 and CD14 and T1D and allergic asthma. Eighteen single nucleotide polymorphisms (SNPs) were genotyped in TLR2 (2), TLR4 (12) and CD14 (4) in 700 T1D children, 357 nuclear families with T1D children and 796 children from the 'Environment and Childhood Asthma' study. Allele and haplotype frequencies were analyzed in relation to diseases and in addition transmission disequilibrium test analyses were performed in the family material. Both T1D and allergic asthma were significantly associated with the TLR2 rs3804100 T allele and further associated with the haplotype including this SNP, possibly representing a susceptibility locus common for the two diseases. Neither TLR4 nor CD14 were associated with T1D or allergic asthma.

Agreement between parental reports and patient records in food allergies among infants and young children in Finland

RATIONALE, AIMS AND OBJECTIVES

A third of parents suspect food allergy in their children. Questionnaire-based studies usually overestimate the occurrence of food allergies. The aim of the present study was to validate a study questionnaire by comparing children's use of special diets as reported by parents with patient records at the hospital.

METHODS

A population-based cohort with genetic susceptibility to type 1 diabetes (15% of those screened) was recruited in the Tampere area between 1997 and 2001, and followed for development of food allergy for 3 years. Food allergies and other special diets were queried at the age of 3 years with a structured questionnaire. The hospital records of the children, whose parents had reported an elimination diet of the child, were studied to validate the parental reports of food allergies. The hospital database was also checked for the respective diagnosis codes to estimate underreporting.

RESULTS

Altogether, 1122 parents returned the questionnaire at the study center visit when the child was 3 years old. Food allergy was reported by 15.0% of the parents. In 10.6% of the children food allergy had been diagnosed or confirmed at the hospital. Hospital-confirmed food allergy was unreported in 0.9% of the cases. The measure of agreement between reported and hospital-confirmed food allergies, using crosstabulation with Cohen's Kappa, was within 0.71-0.88 for cow's milk allergy, 0.74-0.82 for cereal allergy and 0.66-0.86 for any reported food allergy.

CONCLUSION

We found that the validity of the questionnaire obtaining information on food allergies of infants and young children was good to excellent based on a comparison between parental reports and information obtained from patient records.

Maternally reported food allergies and other food-related health problems in infants: characteristics and associated factors

OBJECTIVE

Our goal was to identify the frequency, demographics, and diagnostic characteristics associated with maternally reported food allergies and other food-related health problems among infants aged < or = 1 year.

METHODS

We analyzed data from the 2005-2007 Infant Feeding Practices Study II, a longitudinal survey of 2441 US mothers of healthy singletons from pregnancy through their infant's first year. Doctor diagnosis and symptoms-based criteria were used to identify a probable-food-allergic group from maternal reports of infant health problems with food.

RESULTS

More than one fifth of the 2441 mothers reported that their infant had a food-related problem; 6% (n = 143) had a probable food allergy, and 15% (n = 359) had other food-related problems. Forty percent of the infants with a food-related health problem were evaluated by a doctor. Gastrointestinal symptoms were more commonly reported in early infancy compared with skin-related symptoms, which were reported in later infancy, and 27% received medical treatment for the symptoms. Characteristics associated with increased incidence of probable food allergy included family histories of food allergy and type 1 diabetes, gestational diabetes, living in rural or urban areas, being black, and being male. Among all infants with a food-related health problem, the majority experienced their first problem by 6 months of age. Foods recognized to be major allergens were most commonly reported as the source of an allergy.

CONCLUSIONS

Food-related problems occurred at a high frequency in the first year of life. A better understanding of the demographics, family history, disease manifestations, and diagnoses may provide insight into public health efforts to minimize or prevent food allergies in infancy and to help differentiate food-allergic problems from nonallergic food problems in this age group.

Atopy, home environment and the risk of childhood-onset type 1 diabetes: a population-based case-control study

BACKGROUND

The marked increases in the incidence of type 1 diabetes in recent decades strongly suggest the role of environmental influences. These environmental influences remain largely unknown.

OBJECTIVE

To investigate atopy and home environment (such as children living at home, sharing a bedroom and house moves) as potential risk factors for type 1 diabetes.

SUBJECTS AND METHOD

In Northern Ireland, 175 children with type 1 diabetes and 4859 control children completed a questionnaire on atopy experience, family composition and home environment. Control children from two age groups (6-8 yr old and 13-14 yr old) were identified from randomly selected primary and secondary schools across Northern Ireland. Cases were identified from a population-based type 1 diabetes register.

RESULTS

There was little evidence of a difference in the proportion of participants with a history of atopy in the cases compared with controls. There was a significant reduction in the risk of diabetes in children who lived with more siblings {odds ratio (OR) = 0.58 [95% confidence interval (95% CI) 0.39-0.85] in children who lived with three or more siblings compared with one or none} and in children who moved house more often [OR = 0.59 (95% CI 0.40-0.88) in children who moved house twice or more compared with never].

CONCLUSION

The reduced risk of type 1 diabetes in children living with siblings, sharing a bedroom and moving house more often could reflect the protection afforded by exposure to infections in early life and consequently may provide support for the hygiene hypothesis.

Caesarean section is associated with an increased risk of childhood-onset type 1 diabetes mellitus: a meta-analysis of observational studies

AIMS/HYPOTHESIS

The aim of this study was to investigate the evidence of an increased risk of childhood-onset type 1 diabetes in children born by Caesarean section by systematically reviewing the published literature and performing a meta-analysis with adjustment for recognised confounders.

METHODS

After MEDLINE, Web of Science and EMBASE searches, crude ORs and 95% CIs for type 1 diabetes in children born by Caesarean section were calculated from the data reported in each study. Authors were contacted to facilitate adjustments for potential confounders, either by supplying raw data or calculating adjusted estimates. Meta-analysis techniques were then used to derive combined ORs and to investigate heterogeneity between studies.

RESULTS

Twenty studies were identified. Overall, there was a significant increase in the risk of type 1 diabetes in children born by Caesarean section (OR 1.23, 95% CI 1.15-1.32, p < 0.001). There was little evidence of heterogeneity between studies (p = 0.54). Seventeen authors provided raw data or adjusted estimates to facilitate adjustments for potential confounders. In these studies, there was evidence of an increase in diabetes risk with greater birthweight, shorter gestation and greater maternal age. The increased risk of type 1 diabetes after Caesarean section was little altered after adjustment for gestational age, birth weight, maternal age, birth order, breast-feeding and maternal diabetes (adjusted OR 1.19, 95% CI 1.04-1.36, p = 0.01).

CONCLUSIONS/INTERPRETATION

This analysis demonstrates a 20% increase in the risk of childhood-onset type 1 diabetes after Caesarean section delivery that cannot be explained by known confounders.

Prevalence and associated factors of allergic rhinitis and atopic dermatitis in children

Allergic disorders are the chronic diseases of greatest pediatric morbidity, affecting over 25 % of the pediatric population. Indeed, this situation has been referred to as an "allergic epidemic". In comparison with asthma, atopic dermatitis and allergic rhinitis have been less extensively investigated, although this does not mean that they should be regarded as minor disorders but rather as alterations that affect the quality of life of the patients and their families, which generate considerable direct and indirect costs. Despite an important research effort, the reason for this allergic epidemic is not well known. These are multifactor disorders without a single causal agent, in which the most important component is the genetic predisposition of the patient (atopy), modulated by environmental factors, exposure to allergens, infections and irritants, among others. A confounding element is the fact that the concept of allergic diseases encompasses phenotypes of rhinitis, atopic dermatitis or asthma in which no IgE-mediated atopic mechanism is demonstrated, and which can manifest in a way similar to true allergic phenotypes. Differentiation between the two is difficult to establish on the basis of self-administered questionnaires alone, in the absence of a precise etiological diagnosis. The present article reviews the numerous factors suggested to be responsible for the increase in allergic diseases recorded in the last few decades, and for the differences in prevalence observed among centres. For most of these factors the results published in the literature are contradictory, in some cases due to a lack of control of the associated interacting or confounding factors. Consensus exists for only some of these causal factors, such as the established parallelism between the increase in allergic diseases and the reduction in infectious processes on one hand, and the increase in particles generated by diesel fuel combustion on the other. In addition, the implicated factors could act differently (and in some cases even antagonically) upon atopy and on the different disease phenotypes, thereby complicating the study of these interactions even further.

Frequency of atopy and allergic disorders among adults with Type 1 diabetes mellitus in the southern Marmara region of Turkey

AIM

Autoimmune disorders are considered to be associated with a Th1 immune response whereas allergic diseases with a Th2 response. Studies mainly performed on children revealed conflicting results regarding the association of atopy/allergic disease and autoimmune disorders. Therefore, we aimed to investigate the prevalence of allergic diseases in adult Type 1 diabetic patients.

METHODS

Eighty-nine Type 1 diabetic patients and 64 controls were enrolled into the study. Skin-prick test and European Community Respiratory Health Survey questionnaire were performed on all cases. Patients who gave at least one positive answer to questions about asthma in the questionnaire underwent pulmonary function test and methacholine challenge test.

RESULTS

Patients' mean age were similar in diabetic patients and controls (28.2+/-8.9 and 28.1+/-5.2 yr; respectively). In skin-prick test, the rate of positive response to at least one allergen was not significantly different in diabetes (29.2%) and in the control group (31.3%). In European Community Respiratory Health Survey questionnaire, diabetic patients waked up by an attack of cough more than controls did. The rate of physician-diagnosed asthma was similar in both groups. There was no difference between the 2 groups based on the answers of other questions about asthma and other allergic diseases such as allergic rhinitis, eczema, and drug allergy.

CONCLUSION

We found that atopy frequencies were similar in an adult population of Type 1 diabetic patients and controls. Although asthmatic symptom prevalence is increased in diabetic patients, the incidence of current asthma was similar in both groups.