Association between Asthma and Type 2 Diabetes Mellitus: Mechanisms and Impact on Asthma Control-A Literature Review

Trajectory of lung function in diabetic adults: A 16-year follow-up study of community-based prospective cohorts

BACKGROUND AND OBJECTIVE

To investigate the difference in lung function according to diabetes status in a community-based prospective study.

METHODS

Individuals aged 40-69 years from two community-based cohorts were followed prospectively for 16 years. A spirometer was used to evaluate lung function at baseline, and lung function tests were carried out biennially thereafter. Multivariable linear regression analysis was performed for the cross-sectional and longitudinal analyses based on diabetes status.

RESULTS

Among the 6483 subjects, 2114 (32.6%) had prediabetes and 671 (10.4%) had diabetes. The prediabetes and diabetes groups had lower baseline % predicted values of forced expiratory volume in 1 s (FEV1) (mean, -1.853; 95% confidence interval [CI] -2.715 to -0.990 for prediabetes and mean, -4.088; 95% CI -5.424 to -2.752 for diabetes) and forced vital capacity (FVC) (mean, -2.087; 95% CI -2.837 to -1.337 for prediabetes and mean, -4.622; 95% CI -5.784 to -3.460 for diabetes) compared to the normoglycemia group after adjusting for relevant covariates. The rate of decline in FEV1% predicted (mean, -0.227; 95% CI -0.366 to -0.089) and FVC % predicted (mean, -0.232; 95% CI -0.347 to -0.117) during follow-up were faster in the diabetes group than in the normoglycemia group. The diabetes group had a lower proportion of normal ventilation (ptrend = 0.048) and higher proportions of restrictive (ptrend = 0.001) and mixed (ptrend = 0.035) ventilatory disorders at the last follow-up.

CONCLUSION

Diabetes is associated with a lower baseline lung function and a faster rate of deterioration.

TGF-β, IL-1β, IL-6 levels and TGF-β/Smad pathway reactivity regulate the link between allergic diseases, cancer risk, and metabolic dysregulations

The risk of cancer is higher in patients with asthma compared to those with allergic rhinitis for many types of cancer, except for certain cancers where a contrasting pattern is observed. This study offers a potential explanation for these observations, proposing that the premalignant levels of circulating transforming growth factor-β (TGF-β), IL-1β, and IL-6 as well as the reactivity of the TGF-β/Smad signaling pathway at the specific cancer site, are crucial factors contributing to the observed disparities. Circulating TGF-β, IL- β and IL-6 levels also help clarify why asthma is positively associated with obesity, Type 2 diabetes, hypertension, and insulin resistance, whereas allergic rhinitis is negatively linked to these conditions. Furthermore, TGF-β/Smad pathway reactivity explains the dual impact of obesity, increasing the risk of certain types of cancer while offering protection against other types of cancer. It is suggested that the association of asthma with cancer and metabolic dysregulations is primarily linked to the subtype of neutrophilic asthma. A binary classification of TGF-β activity as either high (in the presence of IL-1β and IL-6) or low (in the presence or absence of IL-1β and IL-6) is proposed to differentiate between allergy patients prone to cancer and metabolic dysregulations and those less prone. Glycolysis and oxidative phosphorylation, the two major metabolic pathways utilized by cells for energy exploitation, potentially underlie this dichotomous classification by reprogramming metabolic pathways in immune cells.

Increased di-(2-ethylhexyl) phthalate exposure poses a differential risk for adult asthma clusters

BACKGROUND

DEHP, a common plasticizer known for its hormone-disrupting properties, has been associated with asthma. However, a significant proportion of adult asthma cases are "non-atopic", lacking a clear etiology.

METHODS

In a case-control study conducted between 2011 and 2015, 365 individuals with current asthma and 235 healthy controls from Kaohsiung City were enrolled. The control group comprised individuals without asthma, Type 2 Diabetes Mellitus (T2DM), hypertension, or other respiratory/allergic conditions. The study leveraged asthma clusters (Clusters A to F) established in a prior investigation. Analysis involved the examination of urinary DEHP metabolites (MEHP and MEHHP), along with the assessment of oxidative stress, sphingolipid metabolites, and inflammatory biomarkers. Statistical analyses encompassed Spearman's rank correlation coefficients, multiple logistic regression, and multinomial logistic regression.

RESULTS

Asthma clusters (E, D, C, F, A) exhibited significantly higher ORs of MEHHP exposures compared to the control group. When considering asthma-related comorbidities (T2DM, hypertension, or both), patients without comorbidities demonstrated significantly higher ORs of the sum of primary and secondary metabolites (MEHP + MEHHP) and MEHHP compared to those with asthma comorbidities. A consistent positive correlation between urinary HEL and DEHP metabolites was observed, but a consistent negative correlation between DEHP metabolites and selected cytokines was identified.

CONCLUSION

The current study reveals a heightened risk of MEHHP and MEHP + MEHHP exposure in specific asthma subgroups, emphasizing its complex relationship with asthma. The observed negative correlation with cytokines suggests a new avenue for research, warranting robust evidence from epidemiological and animal studies.

Preserved Ratio Impaired Spirometry (PRISm): A Global Epidemiological Overview, Radiographic Characteristics, Comorbid Associations, and Differentiation from Chronic Obstructive Pulmonary Disease

Preserved Ratio Impaired Spirometry (PRISm) manifests notable epidemiological disparities across the globe, with its prevalence and influential factors showcasing pronounced diversities among various geographical territories and demographics. The prevalence of PRISm fluctuates considerably among regions such as Latin America, the United States, and Asian nations, potentially correlating with a myriad of determinants, including socioeconomic status, environmental factors, and lifestyle modalities. Concurrently, the link between PRISm and health risks and other disorders, especially its distinction and interrelation with chronic obstructive pulmonary disease (COPD), has become a pivotal subject of scientific enquiry. Radiographic anomalies, such as perturbations in the pulmonary parenchyma and structural alterations, are posited as salient characteristics of PRISm. Furthermore, PRISm unveils intricate associations with multiple comorbidities, inclusive of hypertension and type 2 diabetes, thereby amplifying the intricacy in comprehending and managing this condition. In this review, we aim to holistically elucidate the epidemiological peculiarities of PRISm, its potential aetiological contributors, its nexus with COPD, and its association with radiographic aberrations and other comorbidities. An integrative understanding of these dimensions will provide pivotal insights for the formulation of more precise and personalised preventative and therapeutic strategies.

Basis of preventive and non-pharmacological interventions in asthma

Asthma is one of the most common atopic disorders in all stages of life. Its etiology is likely due to a complex interaction between genetic, environmental, and lifestyle factors. Due to this, different non-pharmacological interventions can be implemented to reduce or alleviate the symptoms caused by this disease. Thus, the present narrative review aimed to analyze the preventive and non-pharmacological interventions such as physical exercise, physiotherapy, nutritional, ergonutritional, and psychological strategies in asthma treatment. To reach these aims, an extensive narrative review was conducted. The databases used were MedLine (PubMed), Cochrane (Wiley), Embase, PsychINFO, and CinAhl. Asthma is an immune-mediated inflammatory condition characterized by increased responsiveness to bronchoconstrictor stimuli. Different factors have been shown to play an important role in the pathogenesis of asthma, however, the treatments used to reduce its incidence are more controversial. Physical activity is focused on the benefits that aerobic training can provide, while physiotherapy interventions recommend breathing exercises to improve the quality of life of patients. Nutritional interventions are targeted on implement diets that prioritize the consumption of fruits and vegetables and supplementation with antioxidants. Psychological interventions have been proposed as an essential non-pharmacological tool to reduce the emotional problems associated with asthma.

Variants in JAZF1 are associated with asthma, type 2 diabetes, and height in the United Kingdom biobank population

Background: Asthma, type 2 diabetes (T2D), and anthropometric measures are correlated complex traits that all have a major genetic component. Objective: To investigate the overlap in genetic variants associated with these complex traits. Methods: Using United Kingdom Biobank data, we performed univariate association analysis, fine-mapping, and mediation analysis to identify and dissect shared genomic regions associated with asthma, T2D, height, weight, body mass index (BMI), and waist circumference (WC). Results: We found several genome-wide significant variants in and around the JAZF1 gene that are associated with asthma, T2D, or height with two of these variants shared by the three phenotypes. We also observed an association in this region with WC when adjusted for BMI. However, there was no association with WC when it was not adjusted for BMI or weight. Additionally, only suggestive associations between variants in this region and BMI were observed. Fine-mapping analyses suggested that within JAZF1 there are non-overlapping regions harboring causal susceptibility variants for asthma, T2D, and height. Mediation analyses supported the conclusion that these are independent associations. Conclusion: Our findings indicate that variants in the JAZF1 are associated with asthma, T2D, and height, but the associated causal variant(s) are different for each of the three phenotypes.

Impact of Comorbidity of Bronchial Asthma and Type 2 Diabetes Mellitus on the Expression and Functional Activity of TLR2 and TLR4 Receptors

Epidemiological data indicate the active progression of various forms of diabetes mellitus in patients with bronchial asthma (BA), but little is known about the mechanisms of comorbidity formation. TLR2 and TLR4 are involved in the progression of asthma and type 2 diabetes mellitus (T2DM). These receptors are involved in the inflammatory response to Gram(+) and Gram(-) bacteria, respectively, so changes in their expression may affect the predisposition of patients to bacteremia. The aim of this study was to analyze the expression and functional activity of toll-like receptor 2 and 4 (TLR2 and TLR4) on peripheral blood cells of patients with BA, T2DM, and BA + T2DM. The expression of TLR2 and TLR4 was analyzed by flow cytometry. Whole blood samples were incubated with lipopolysaccharides from E. coli (LPS) and lipoteichoic acid from S. pyogenes (LTA). The concentration of cytokines and soluble blood proteins was determined by ELISA. Patients with comorbid diseases showed a statistically significant increase in TLR2 expression on both monocytes and neutrophils compared with healthy donors and patients with BA. We found increased expression of TLR4 on the surface of blood monocytes from patients compared to donors. The activation of blood cells of patients and donors with LPS or LTA led to an increase in the expression of "fast" pro-inflammatory cytokines (TNF-α, IL-6). In patients with BA, the average production of TNF-α in response to endotoxin was two times higher than in other studied groups. The reactions of blood cells in patients with T2DM and BA + T2DM did not differ significantly. The expression and functional activity of TLR2 and TLR4 on the blood cells of patients with comorbid disease were similar to those only in patients with T2DM. The greatest increase in the synthesis of the pro-inflammatory cytokine TNF-α in response to LPS and LTA was observed in patients with BA, which can lead to an inadequate response to bacteremia.

Role of Leptin as a Link between Asthma and Obesity: A Systematic Review and Meta-Analysis

Asthma and obesity are considered as highly prevalent diseases with a great impact on public health. Obesity has been demonstrated to be an aggravating factor in the pathogenesis of asthma. Adipose tissue secretes proinflammatory cytokines and mediators, including leptin, which may promote the development and severity of asthma in obese patients. This study is a systematic review and a meta-analysis based on the relationship between leptin and asthma during obesity. MEDLINE, Cochrane, EMBASE and CINAHL databases were used. Data heterogeneity was analyzed using Cochran’s Q and treatment effect with the DerSimonian and Laird method. Random effect analyses were carried out to test data sensitivity. Asymmetry was estimated using Begg’s and Egger’s tests. All studies showed significant differences in leptin levels. The effect of the measures (p < 0.001), data sensitivity (p < 0.05) and data asymmetry were statistically significant, as well as tBegg’s test (p = 0.010) and Egge’s test (p < 0.001). Despite the existing limiting factors, the results of this study support the relevant role of leptin in the pathophysiology of asthma in obese subjects. Nevertheless, further studies are needed to obtain better insight in the relationship between leptin and asthma in obesity.

Multi-ancestry meta-analysis of asthma identifies novel associations and highlights the value of increased power and diversity

Asthma is a complex disease that varies widely in prevalence across populations. The extent to which genetic variation contributes to these disparities is unclear, as the genetics underlying asthma have been investigated primarily in populations of European descent. As part of the Global Biobank Meta-analysis Initiative, we conducted a large-scale genome-wide association study of asthma (153,763 cases and 1,647,022 controls) via meta-analysis across 22 biobanks spanning multiple ancestries. We discovered 179 asthma-associated loci, 49 of which were not previously reported. Despite the wide range in asthma prevalence among biobanks, we found largely consistent genetic effects across biobanks and ancestries. The meta-analysis also improved polygenic risk prediction in non-European populations compared with previous studies. Additionally, we found considerable genetic overlap between age-of-onset subtypes and between asthma and comorbid diseases. Our work underscores the multi-factorial nature of asthma development and offers insight into its shared genetic architecture.

Dapagliflozin mitigates ovalbumin-prompted airway inflammatory-oxidative successions and associated bronchospasm in a rat model of allergic asthma

BACKGROUND

Asthma is a chronic inflammatory lung disease that universally affects millions of people. Despite numerous well-defined medications, asthma is poorly managed. The study aimed to clarify the potential therapeutic effect of Dapagliflozin (DAPA) against lung inflammation, oxidative stress and associated bronchospasm in OVA-sensitized rat asthma model.

RESEARCH DESIGN AND METHODS

Twenty-five rats were allocated into (Control, Asthma, DEXA, DAPA, and DAPA+DEXA). All treatments were administered orally once a day for two weeks. BALF levels of IL-17, TNFα, IL-1β, and MCP-1 were determined to assess airway inflammation. For oxidative stress determination, BALF MDA levels and TAC were measured. The BALF S100A4 level and NO/sGC/cGMP pathway were detected. Lung histopathological findings and immunohistochemical investigation of eNOS and iNOS activities were recorded.

RESULTS

DAPA significantly reduced (p < 0.001) airway inflammatory-oxidative markers (IL-17, TNFα, IL-1β, MCP1, and MDA), but increased (p < 0.001) TAC, and mitigated bronchospasm by activating NO/sGC/cGMP and reducing S100A4 (p < 0.001). The biochemical and western blot studies were supported by histopathological and immunohistochemical investigations.

CONCLUSIONS

: DAPA is presenting a new prospective possibility for future asthma therapy due to its anti-inflammatory, anti-oxidant, and bronchodilator properties. DAPA has the property of reducing Dexamethasone (DEXA)-associated unfavorable effects during asthma treatment.