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

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.

Sociodemographic factors, health behavior, parental or workplace smoking, and adult asthma risk in the United States

BACKGROUND

Although several studies have found a link between parental or workplace smoking and asthma risk, particularly in children and adolescents, only a few studies have found this link in adults.

OBJECTIVE

This study aimed to investigate the associations of sociodemographic factors, health behavior, and parental or workplace smoking with adult asthma risk in the United States (US).

METHODS

A secondary data analysis on 874 participants aged 25-45 was performed using data from the 2011-2014 National Survey of Midlife Development in the United States Refresher. Participants were divided into smokers and nonsmokers. Participants were further divided into groups A (a father or mother with a smoking history) and B (others in the house or colleagues in the workplace who had a smoking history).

RESULTS

Findings from the FREQ procedure revealed that sociodemographic (female, black, school or college education, unmarried/divorced, and employed) and lifestyle (no alcohol intake, physically inactive, and obese) and clinical (diabetes and joint disease) factors were significantly associated with one- or more-fold odds of asthma among adult smokers than nonsmokers. Adult smokers in group A, particularly females, those with a high school or college education, physically inactive, and overweight or obese, had a higher risk of asthma than those in group B.

CONCLUSION

Adult smokers' risk of developing asthma is increased in the US by having smoked with their parents, being a woman, being black, having a school or college education, being single or divorced, working, not drinking alcohol, being physically inactive, being obese, having diabetes, and having a joint 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.

Multiancestral polygenic risk score for pediatric asthma

BACKGROUND

Asthma is the most common chronic condition in children and the third leading cause of hospitalization in pediatrics. The genome-wide association study catalog reports 140 studies with genome-wide significance. A polygenic risk score (PRS) with predictive value across ancestries has not been evaluated for this important trait.

OBJECTIVES

This study aimed to train and validate a PRS relying on genetic determinants for asthma to provide predictions for disease occurrence in pediatric cohorts of diverse ancestries.

METHODS

This study applied a Bayesian regression framework method using the Trans-National Asthma Genetic Consortium genome-wide association study summary statistics to derive a multiancestral PRS score, used one Electronic Medical Records and Genomics (eMERGE) cohort as a training set, used a second independent eMERGE cohort to validate the score, and used the UK Biobank data to replicate the findings. A phenome-wide association study was performed using the PRS to identify shared genetic etiology with other phenotypes.

RESULTS

The multiancestral asthma PRS was associated with asthma in the 2 pediatric validation datasets. Overall, the multiancestral asthma PRS has an area under the curve (AUC) of 0.70 (95% CI, 0.69-0.72) in the pediatric validation 1 and AUC of 0.66 (0.65-0.66) in the pediatric validation 2 datasets. We found significant discrimination across pediatric subcohorts of European (AUC, 95% CI, 0.60 and 0.66), African (AUC, 95% CI, 0.61 and 0.66), admixed American (AUC, 0.64 and 0.70), Southeast Asian (AUC, 0.65), and East Asian (AUC, 0.73) ancestry. Pediatric participants with the top 5% PRS had 2.80 to 5.82 increased odds of asthma compared to the bottom 5% across the training, validation 1, and validation 2 cohorts when adjusted for ancestry. Phenome-wide association study analysis confirmed the strong association of the identified PRS with asthma (odds ratio, 2.71, PFDR = 3.71 × 10-65) and related phenotypes.

CONCLUSIONS

A multiancestral PRS for asthma based on Bayesian posterior genomic effect sizes identifies increased odds of pediatric asthma.

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.

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.

Trends in asthma among adults in the United States, National Health and Nutrition Examination Survey 2005 to 2018

BACKGROUND

Asthma is a common chronic disease in American adults. The prevalence of asthma has varied over time, but there are few studies on the long-term trend of asthma in American adults.

OBJECTIVE

To describe the prevalence and trend of asthma in American adults from 2005 to 2018 and analyze the risk factors for asthma.

METHODS

Data collection was performed from National Health and Nutrition Examination Survey 2005 to 2018. The unweighted number and weighted percentages of normal participants and patients with asthma and the trends of asthma were calculated. Weighted univariate logistic regression was used to analyze the risk factors for asthma.

RESULTS

A total of 39,601 adults were included in this study. From 2005 to 2018, the overall prevalence of asthma in American adults was 8.41%, whereas that in young, middle-aged, and elderly adults was 8.30%, 8.70%, and 7.92%, respectively. The estimated prevalence of asthma in the overall adults and young adults increased with time (P for trend = .03, difference = 0.023 and P for trend = .007, difference = 0.060, respectively), and the estimated prevalence of middle-aged and elderly adults remained stable with time (P for trend = .33, difference = 0.015 and P for trend = .80, difference = -0.024, respectively).

CONCLUSION

Asthma in American adults was on the rise. Female sex, non-Hispanic Blacks, individuals with low annual household income, active smokers, obese patients, patients with hypertension, patients with diabetes, and individuals with positive asthma family history were associated with a higher risk for developing asthma.

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.

Therapeutic approaches targeting molecular signaling pathways common to diabetes, lung diseases and cancer

Diabetes mellitus (DM), is the most common metabolic disease and is characterized by sustained hyperglycemia. Accumulating evidences supports a strong association between DM and numerous lung diseases including chronic obstructive pulmonary disease (COPD), fibrosis, and lung cancer (LC). The global incidence of DM-associated lung disorders is rising and several ongoing studies, including clinical trials, aim to elucidate the molecular mechanisms linking DM with lung disorders, in particular LC. Several potential mechanisms, including hyperglycemia, hyperinsulinemia, glycation, inflammation, and hypoxia, are cited as plausible links between DM and LC. In addition, studies also propose a connection between the use of anti-diabetic medications and reduction in the incidence of LC. However, the exact cause for DM associated lung diseases especially LC is not clear and is an area under intense investigation. Herein, we review the biological links reported between DM and lung disorders with an emphasis on LC. Furthermore, we report common signaling pathways (eg: TGF-β, IL-6, HIF-1, PDGF) and miRNAs that are dysregulated in DM and LC and serve as molecular targets for therapy. Finally, we propose a nanomedicine based approach for delivering therapeutics (eg: IL-24 plasmid DNA, HuR siRNA) to disrupt signaling pathways common to DM and LC and thus potentially treat DM-associated LC. Finally, we conclude that the effective modulation of commonly regulated signaling pathways would help design novel therapeutic protocols for treating DM patients diagnosed with LC.

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.

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.

The Interplay Between Asthma and Other Diseases: Role of Ca2+/cAMP Signalling

OBJECTIVE

Asthma is correlated with a higher risk of manifesting other diseases, including hypertension, diabetes, obesity, psychiatric and neurological diseases, and cancer. Therefore, revealing this interplay between asthma and these illnesses may provide novel insights into their pathogenesis.

RESULTS

It is highly debated that dysregulation of Ca2+ homeostasis is involved in the pathogenesis of these maladies. Not surprisingly, calcium (Ca2+) channel blockers (CCBs), classically used as antihypertensive medicines, have been demonstrating off-label effects such as alleviating asthma symptoms, in addition to antidiabetic, antiobesity, anticancer and antineurodegenerative effects. Our studies about Ca2+/cAMP signalling may shed some new light on this field.

CONCLUSION

Thus, considering that asthma and associated illnesses such as hypertension, diabetes, obesity, cancer and neurodegenerative diseases have become highly prevalent medical problems in the world, the comprehension of this interplay between asthma and other disorders could improve drug therapy.

DM-induced Hypermethylation of IR and IGF1R attenuates mast cell activation and airway responsiveness in rats

Diabetes has been reported to modulate the airway smooth muscle reactivity and lead to attenuation of allergic inflammatory response in the lungs. In this study, we aimed to study the effect of insulin on cell activation and airway responsiveness in patients with diabetes mellitus (DM). The airway contraction in rat model groups including a non‐DM group, a non‐DM+INDUCTION group, a DM+INDUCTION group and a DM+INDUCTION+INSULIN group was measured to observe the effect of insulin on airway responsiveness. Radioenzymatic assay was conducted to measure the levels of histamine, and ELISA assay was conducted to measure bronchial levels of interleukin (IL)‐1b, tumour necrosis factor (TNF)‐a, cytokine‐induced neutrophil chemoattractant (CINC)‐1, P‐selectin and β‐hexosaminidase. The tension in the main and intrapulmonary bronchi of DM+INDUCTION rats was lower than that of the non‐DM+INDUCTION rats, whereas the treatment of insulin partly restored the normal airway responsiveness to OA in DM rats. The release of histamine was remarkably suppressed in DM+INDUCTION rats but was recovered by the insulin treatment. Also, OA significantly increased the levels of IL‐1b, TNF‐a, CINC‐1 and P‐selectin in non‐DM rats, whereas insulin treatment in DM+INDUCTION rats partly restored the normal levels of IL‐1b, TNF‐a, CINC‐1 and P‐selectin in DM rats. Moreover, the expression of IR and IGF1R was evidently suppressed in DM rats, with the methylation of both IR and IGF1R promoters was aggravated in DM rats. Therefore, we demonstrated that DM‐induced hypermethylation inhibited mast cell activation and airway responsiveness, which could be reversed by insulin treatment.

The Prevalence of Autoimmune Diseases in Longstanding Diabetes: Results from the Canadian Study of Longevity in Adults with Type 1 Diabetes

OBJECTIVE

We aimed to determine the prevalence of autoimmune diseases (e.g. thyroid disease, celiac disease, etc) in Canadians with longstanding type 1 diabetes (T1D) and to explore sex-specific differences and the association with complications.

METHODS

Cross-sectional data were analyzed in an exploratory secondary analysis from the Canadian Study of Longevity in Type 1 Diabetes, a nationwide registry of people with T1D of at least 50 years' duration. In total, 374 participants provided self-reported questionnaire data and physician-reported laboratory results. Student's t-test, the Wilcoxon rank-sum test, the χ² test and logistic regression were used to identify associations with autoimmune diseases.

RESULTS

The 374 participants had a median T1D duration of 53 years (interquartile range, 51 to 58) and a median age of onset of 11 years (6 to 16), and 57.1% were females. Females had a greater prevalence of autoimmune diseases (60.6% vs 34.4%, p<0.001). Thyroid disease was most prevalent (41%, 153/374), especially in females (51.6% vs 26.9%), and the prevalence of 1 or more autoimmune disease was 49.3% (184/374). Autoimmune disease was associated with lower odds of cardiovascular disease (CVD)-odds ratio [OR] 0.61, 95% confidence interval [CI] 0.37 to 1.00 for thyroid autoimmune disease and OR 0.34 (95% CI 0.12 to 0.93) for nonthyroid autoimmune disease, both compared to those without autoimmune disease (p=0.033). Autoimmune diseases were not associated with the presence of nephropathy, neuropathy or retinopathy.

CONCLUSIONS

Lifetime risk of autoimmune disease in longstanding T1D approaches 50%, is greater in females and is driven by thyroid disease. The probability of diabetes complications, such as CVD, was lower in those with autoimmune disease, which was driven mostly by nonthyroid autoimmune diseases.

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.

Indicators of metabolic syndrome in normotensive normoglycemic asthmatic patients

BACKGROUND

Pathophysiology of hypertension and bronchial asthma (BA) shares many similarities, especially those related to the metabolic syndrome (MS).

AIM

In this study, the indicators of the MS were evaluated in normoglycemic normotensive asthmatic patients to clarify if the components of the MS can still interact to increase the risk of BA, provided that blood pressure and glucose level are kept within the normal physiological ranges.

METHODS

Body mass index (BMI), waist circumference (WC), mean arterial blood pressure (MABP), fasting blood glucose (FBG) and fasting blood insulin (FBI) levels, the quantitative insulin sensitivity check index (QUICKI), serum lipid profile, and spirometric measurements were all compared between 120 asthmatic patients and 59 non-asthmatic subjects. Cigarette smoking, pregnancy, age below 20 years or above 40 years, diabetes mellitus and hypertension, and other chronic diseases were excluded from all studied groups.

RESULTS

Asthmatic patients demonstrated higher WC (median [25th-75th interquartile]=88.50 [78.00-101.75], FBI [19.98 (11.12-40.14)], and triglyceride (TG) level [109.5 (76.50-134.0)]) compared with non-asthmatic subjects (81.00 [72.00-92.00], 13.78 [8.84-30.24], and 89.00 [64.25-104], P<0.05). QUICKI and MABP were lower in asthmatic patients (0.310 [0.283-0.338] and 86.66 [83.33-93.33]) compared with non-asthmatic subjects (0.320 [0.297-0.353] and 93.33 [83.33-93.33]), (P<0.05). BMI, FBG, low-density lipoprotein, high-density lipoprotein, and total cholesterol levels were comparable in the studied groups.

CONCLUSIONS

The present finding gives further evidence for higher WC, FBI, TG level, and insulin resistance in normotensive, normoglycemic asthmatic patients compared to healthy controls.

RELEVANCE FOR PATIENTS

The findings of this study suggested that abdominal obesity, hypertriglyceridemia, hyperinsulinemia, and insulin resistance may still be interacting and hence increase the risk of BA in normotensive, normoglycemic subjects.

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.

Insulin prevents pulmonary vascular leakage by inhibiting transglutaminase 2 in diabetic mice

AIMS

Insulin is a central peptide hormone required for carbohydrate metabolism; however, its role in diabetes-associated pulmonary disease is unknown. Here, we investigated the preventative effect of insulin against hyperglycemia-induced pulmonary vascular leakage and its molecular mechanism of action in the lungs of diabetic mice.

MAIN METHODS

Vascular endothelial growth factor (VEGF) activated transglutaminase 2 (TGase2) by sequentially elevating intracellular Ca²⁺ and reactive oxygen species (ROS) levels in primary human pulmonary microvascular endothelial cells (HPMVECs).

KEY FINDINGS

Insulin inhibited VEGF-induced TGase2 activation, but did not affect intracellular Ca²⁺ elevation and ROS generation. Insulin prevented VEGF-induced vascular leakage by inhibiting TGase2-mediated c-Src phosphorylation, disassembly of VE-cadherin and β-catenin, and stress fiber formation. Insulin replacement therapy prevented hyperglycemia-induced TGase2 activation, but not ROS generation, in the lungs of diabetic mice. Insulin also prevented vascular leakage and cancer metastasis in the diabetic lung. Notably, vascular leakage was not detectable in the lungs of TGase2-null (Tgm2^-/-) diabetic mice.

SIGNIFICANCE

These findings demonstrate that insulin prevents hyperglycemia-induced pulmonary vascular leakage in diabetic mice by inhibiting VEGF-induced TGase2 activation rather than ROS generation.

Hypoxic pulmonary vasoconstriction is lacking in rats with type 1 diabetes

Hypoxic pulmonary vasoconstriction (HPV) is the most important feature of intact lung circulation that matches local blood perfusion to ventilation. The main goal of this work was to study the effects of diabetes on the development of HPV in rats. The experimental design comprised diabetes mellitus induction by streptozotocin, video-morphometric measurements of the lumen area of intrapulmonary arteries (iPAs) using perfused lung tissue slices and patch-clamp techniques. It was shown that iPA lumen size was significantly reduced under physical and chemical hypoxia (7-10 mm Hg) in normal iPA, but, on the contrary, it clearly increased in diabetic lung slices. The amplitude of the outward K⁺ current in diabetic iPAs smooth muscle cells (SMCs) was two-fold greater than that seen in healthy cells. Chemical hypoxia led to significant decrease in the amplitude of the K⁺ outward current in healthy iPA SMCs while it was without effect in diabetic cells. The data obtained clearly indicate a significant dysregulation of vascular tone in pulmonary circulation under diabetes, ie diabetes damages the adaptive mechanism for regulating blood flow from poorly ventilated to better ventilated regions of the lung under hypoxia. This effect could be clinically important for patients with diabetes who have acute or chronic lung diseases associated with the lack of blood oxygenation.

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.

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.

Diabetes and Lung Disease: A Neglected Relationship

BACKGROUND

Diabetes mellitus is a systemic disorder associated with inflammation and oxidative stress which may target many organs such as the kidney, retina, and the vascular system. The pathophysiology, mechanisms, and consequences of diabetes on these organs have been studied widely. However, no work has been done on the concept of the lung as a target organ for diabetes and its implications for lung diseases.

AIM

In this review, we aimed to investigate the effects of diabetes and hypoglycemic agent on lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis, pulmonary hypertension, and lung cancer. We also reviewed the potential mechanisms by which these effects may affect lung disease patients.

RESULTS

Our results suggest that diabetes can affect the severity and clinical course of several lung diseases.

CONCLUSIONS

Although the diabetes-lung association is epidemiologically and clinically well-established, especially in asthma, the underlying mechanism and pathophysiology are not been fully understood. Several mechanisms have been suggested, mainly associated with the pro-inflammatory and proliferative properties of diabetes, but also in relation to micro- and macrovascular effects of diabetes on the pulmonary vasculature. Also, hypoglycemic drugs may influence lung diseases in different ways. For example, metformin was considered a potential therapeutic agent in lung diseases, while insulin was shown to exacerbate lung diseases; this suggests that their effects extend beyond their hypoglycemic properties.

Relationship between diabetes and respiratory diseases-Clinical and therapeutic aspects

Diabetes is a common metabolic disorder affecting the entire body with high morbidity and mortality worldwide. The major complications related to diabetes are mostly due to the macrovascular and microvascular bed impairment due to metabolic, hemodynamic and inflammatory factors. However, studies over the past decades have added also the lung as a target organ in both type 1 and type 2 diabetes. Diabetes has always been addressed as a major comorbidity conditioning the disease behaviour and the natural history of several respiratory diseases. Increased interest has recently focused on the pathophysiology of the metabolic glycaemic disorder and the respiratory diseases suggesting a similar background shared by the two conditions. The true relationship between pulmonary diseases and diabetes mellitus has not been clarified, this review aims to summarize the link between diabetes and coexisting respiratory diseases such as asthma, chronic obstructive pulmonary disease, respiratory infections, cystic fibrosis, lung cancer and obstructive sleep apnea from a pathogenetic and therapeutic point of view.

Effects of Comorbidities on Asthma Hospitalization and Mortality Rates: A Systematic Review

Background

Recent studies have shown that patients diagnosed with asthma who have other chronic comorbidities have severely worse medical outcomes. However, the number of available published studies in this field is lacking. The aim of this study was to determine the effects of comorbidities in asthmatic patients based on hospitalization and mortality rates.

Methods

A systematic review was conducted. Data were obtained from the electronic databases PubMed, CINAHL, and Cochrane until June 15, 2018. The primary objective of this study was to determine the effects of comorbidities on asthma hospitalization and mortality. The secondary objective was to analyze the effects of asthma comorbidity with certain chronic diseases, including COPD, obesity, obstructive sleep apnea, mental illness (anxiety and depression), diabetes mellitus, hypertension, myocardial ischemia, rhinitis, and sinusitis on asthma hospitalization and mortality.

Results

From potential 687 articles, only 9 were chosen based on our study inclusion criteria. Almost half of these articles were related to asthma/COPD comorbidity. There were no articles found for hypertension, myocardial ischemia, rhinitis, or sinusitis based on our inclusion/exclusion factors. Each of these 9 published articles had shown an increase in rates of hospitalization, length of stay, and/or mortality, due to asthma-related symptoms, compared to asthma-only patients.

Conclusion

There was determined to be a large discrepancy between the available research for various types of comorbid conditions presenting with asthma that focus on hospitalization and mortality rates. The current available literature suggests a large impact that these comorbid diseases can have on asthma-related symptoms when present together, severely affecting a patient's quality of life. We propose that further research on the effects of these comorbidities on asthma mortality and hospitalization can yield beneficial results to improve the management of asthmatic patients.

Co-occurrence of Asthma and the Inflammatory Bowel Diseases: A Systematic Review and Meta-analysis

Background

Inflammatory bowel diseases (IBD) and asthma share genetic and environmental risk factors. Consequently, several observational studies have explored an association between IBD and asthma. We systematically reviewed and summarized the literature on the co-occurrence of asthma and IBD.

Methods

MEDLINE and EMBASE (to April 2017) were searched to identify observational studies on the association between asthma and IBD. Relative risks (RR) were pooled using random effects models. Heterogeneity was assessed using the I² and Cochran Q statistics. Meta-regression based on study design, source of patients (population-based vs. tertiary-care center) and study location was conducted to explain between-study heterogeneity.

Results

Eighteen studies were identified (15 Crohn’s disease, 15 ulcerative colitis (UC)). Asthma was associated with both Crohn’s disease (pooled RR 1.30, 95% confidence interval (CI) 1.16–1.47, I² = 88%) and UC (RR 1.34, 95% CI 1.24–1.44, I² = 93%). The study design and source of patients and study location explained between-study heterogeneity in Crohn’s disease, but not UC.

Conclusion

Asthma is associated with both Crohn’s disease and UC. Additional research is needed to determine if one disease influences the risk of developing the other or if the frequent co-occurrence of these diseases result from shared genetic, environmental, and microbial risk factors.

Regulation of contact sensitivity in non-obese diabetic (NOD) mice by innate immunity

BACKGROUND

Genetic background influences allergic immune responses to environmental stimuli. Non-obese diabetic (NOD) mice are highly susceptible to environmental stimuli. Little is known about the interaction of autoimmune genetic factors with innate immunity in allergies, especially skin hypersensitivity.

OBJECTIVES

To study the interplay of innate immunity and autoimmune genetic factors in contact hypersensitivity (CHS) by using various innate immunity-deficient NOD mice.

METHODS

Toll-like receptor (TLR) 2-deficient, TLR9-deficient and MyD88-deficient NOD mice were used to investigate CHS. The cellular mechanism was determined by flow cytometry in vitro and adoptive cell transfer in vivo. To investigate the role of MyD88 in dendritic cells (DCs) in CHS, we also used CD11c^MyD88+  MyD88^-/- NOD mice, in which MyD88 is expressed only in CD11c⁺ cells.

RESULTS

We found that innate immunity negatively regulates CHS, as innate immunity-deficient NOD mice developed exacerbated CHS accompanied by increased numbers of skin-migrating CD11c⁺ DCs expressing higher levels of major histocompatibility complex II and CD80. Moreover, MyD88^-/- NOD mice had increased numbers of CD11c⁺  CD207^-  CD103⁺ DCs and activated T effector cells in the skin-draining lymph nodes. Strikingly, re-expression of MyD88 in CD11c⁺ DCs (CD11c^MyD88+  MyD88^-/- NOD mice) restored hyper-CHS to a normal level in MyD88^-/- NOD mice.

CONCLUSION

Our results suggest that the autoimmune-prone NOD genetic background aggravates CHS regulated by innate immunity, through DCs and T effector cells.

Impact of type 1 diabetes on maternal long-term risk of hospitalisation and mortality: a nationwide combined clinical and register-based cohort study (The EPICOM study)

AIMS/HYPOTHESIS

The aims of this study were to examine long-term mortality and morbidity rates in mothers with type 1 diabetes, both overall and according to the level of albuminuria prior to pregnancy, the presence of hypertension, pre-eclampsia and periconceptional HbA_1c.

METHODS

This study was a part of the EPICOM (Environmental Versus Genetic and Epigenetic Influences on Growth, Metabolism and Cognitive Function in Offspring of Mothers with Type 1 Diabetes) study, which is a prospective follow-up study focusing on pregnancies complicated by maternal type 1 diabetes. We carried out a nationwide combined clinical and register-based cohort study of mortality rates and hospital admissions in mothers with diabetes (n = 986) who gave birth between 1992 and 2000. Control mothers (n = 91,441) were women from the background population, matched according to age and year of childbirth. Age at follow-up was 32-66 years.

RESULTS

Mortality rate was increased threefold in mothers with diabetes compared with control mothers (HR 3.41 [95% CI 2.42, 4.81]; p < 0.0001), and was also increased with pre-gestational kidney dysfunction (normoalbuminuria, HR 2.17 [95% CI 1.28, 3.68]; microalbuminuria, HR 3.36 [95% CI 0.82, 13.8]; macroalbuminuria, HR 12.9 [95% CI 5.45, 30.7]). Moreover, the presence of hypertension prior to or at any time during pregnancy and of pre-eclampsia also increased mortality rate (hypertension, HR 4.34 [95% CI 2.13, 8.84]; pre-eclampsia, HR 5.55 [95% CI 2.71, 11.4]). Mortality rate also increased with higher levels of HbA_1c in early pregnancy (HbA_1c ≤75 mmol/mol [≤9%], HR 2.15 [95% CI 1.31, 3.53]; HbA_1c >75 mmol/mol [>9%], HR 6.10 [95% CI 2.67, 14.0]). However, in mothers with diabetes and HbA_1c <64 mmol/mol (<8%) in the first trimester and normal pre-gestational urinary albumin excretion rate (n = 517), mortality rate was comparable with that of control mothers. Among mothers with diabetes, mortality rate was associated with HbA_1c level: per 11 mmol/mol (1 percentage point) increase in HbA_1c, HR was 1.52 (95% CI 1.19, 1.94; p = 0.001). In mothers with diabetes, the overall incidence of hospital admissions was more than double (incidence rate ratio [IRR] 2.69 [95% CI 2.59, 2.80]; p < 0.0001) that of control mothers, as were admissions with various diagnoses from 14 out of 19 ICD-10 chapters. Among mothers with diabetes, the IRR for hospital admissions increased with the level of HbA_1c: per 11 mmol/mol (1 percentage point) increase in HbA_1c, HR was 1.07 (95% CI 1.04, 1.10; p < 0.0001).

CONCLUSIONS/INTERPRETATION

Overall, mothers with type 1 diabetes have a two- to threefold increase in mortality and morbidity rates. HbA_1c levels, level of albuminuria around the time of conception, and the presence of hypertension and pre-eclampsia are important risk factors for mortality/morbidity in this cohort. However, it is reassuring that mothers with type 1 diabetes without kidney complications and with HbA_1c <64 mmol/mol (<8%) in early pregnancy have a similar survival potential during the period where they are raising their children to that of control mothers from the background population.

Diabetes Downregulates Allergen-Induced Airway Inflammation in Mice

Previous studies described that allergic diseases, including asthma, occur less often than expected in patients with type 1 diabetes. Here, we investigated the influence of diabetes on allergic airway inflammation in a model of experimental asthma in mice. Diabetes was induced by intravenous injection of alloxan into 12 h-fasted A/J mice, followed by subcutaneous sensitization with ovalbumin (OVA) and aluminum hydroxide (Al(OH)₃), on days 5 and 19 after diabetes induction. Animals were intranasally challenged with OVA (25 μg), from day 24 to day 26. Alloxan-induced diabetes significantly attenuated airway inflammation as attested by the lower number of total leukocytes in the bronchoalveolar lavage fluid, mainly neutrophils and eosinophils. Suppression of eosinophil infiltration in the peribronchiolar space and generation of eosinophilotactic mediators, such as CCL-11/eotaxin, CCL-3/MIP-1α, and IL-5, were noted in the lungs of diabetic sensitized mice. In parallel, reduction of airway hyperreactivity (AHR) to methacholine, mucus production, and serum IgE levels was also noted under diabetic conditions. Our findings show that alloxan diabetes caused attenuation of lung allergic inflammatory response in A/J mice, by a mechanism possibly associated with downregulation of IgE antibody production.

Glucagon and glucagon-like peptide-1 as novel anti-inflammatory and immunomodulatory compounds

Glucagon and glucagon-like peptide-1 (GLP-1) are polypeptide hormones that are produced by pancreatic α-cells and the intestine, respectively, whose main function is to control glucose homeostasis. The glucagon and GLP-1 levels are imbalanced in diabetes. Furthermore, type 1 diabetic patients and animals present with a diminished inflammatory response, which is related to some morbidities of diabetes, such as a higher incidence of infectious diseases, including sepsis. The focus of this review is to briefly summarize the state of the art concerning the effects of glucagon and GLP-1 on the inflammatory response. Here, we propose that glucagon and GLP-1 have anti-inflammatory properties, making them possible prototypes for the design and synthesis of new compounds to treat inflammatory diseases. In addition, glucagon, GLP-1 or their analogues or new derivatives may not only be important for managing inflammatory diseases but may also have the therapeutic potential to prevent, cure or ameliorate diabetes in patients by counteracting the deleterious effects of pro-inflammatory cytokines on the function and viability of pancreatic β-cells. In addition, GLP-1, its analogues or drugs that inhibit GLP-1 metabolism may have a doubly beneficial effect in diabetic patients by inhibiting the inflammatory response and reducing glycaemia.

Potential Biochemical Mechanisms of Lung Injury in Diabetes

Accumulating evidence has shown that the lung is one of the target organs for microangiopathy in patients with either type 1 or type 2 diabetes mellitus (DM). Diabetes is associated with physiological and structural abnormalities in the diabetic lung concurrent with attenuated lung function. Despite intensive investigations in recent years, the pathogenic mechanisms of diabetic lung injury remain largely elusive. In this review, we summarize currently postulated mechanisms of diabetic lung injury. We mainly focus on the pathogenesis of diabetic lung injury that implicates key pathways, including oxidative stress, non-enzymatic protein glycosylation, polyol pathway, NF-κB pathway, and protein kinase c pathway. We also highlight that while numerous studies have mainly focused on tissue or cell damage in the lung, studies focusing on mitochondrial dysfunction in the diabetic lung have remained sketchy. Hence, further understanding of mitochondrial mechanisms of diabetic lung injury should provide invaluable insights into future therapeutic approaches for diabetic lung injury.

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.