Metformin and the Development of Asthma in Patients with Type 2 Diabetes

Impact of metabolic and weight components on incident asthma using a real-world cohort

BACKGROUND

Obesity and metabolic dysregulation (MetD) have increasing prevalence and adversely affect asthma morbidity and therapeutic response.

OBJECTIVE

To determine the role of weight and MetD on incident asthma in adulthood.

METHODS

In a retrospective, longitudinal cohort of patients, we performed a time-to-asthma diagnosis analysis after a 3-year landmark period (t0-t3) during which weight and MetD components were evaluated. We assessed incident asthma risk with MetD components and weight.

RESULTS

In total, 90,081 patients met the inclusion criteria, with 836 cases (0.93%) of incident asthma in our primary cohort. Diabetes present at t0, but no other MetD components, was associated with increased risk of asthma (adjusted hazard ratio = 1.85, 95% CI: 1.27-2.71, P = .0002). The effect of weight on asthma risk, independent of other MetD components, identified individuals with overweight or obesity as having a 10-year attributable risk of 15.4%. Metformin was prescribed more frequently, and hemoglobin A1c levels were lower in patients with diabetes in whom asthma did not develop (P < .0001).

CONCLUSION

Weight and diabetes prevention and management represent modifiable risk factors for adult asthma development.

Obesity-related Asthma: A Pathobiology-based Overview of Existing and Emerging Treatment Approaches

Although obesity-related asthma is associated with worse asthma outcomes, optimal treatment approaches for this complex phenotype are still largely unavailable. This state-of-the-art review article synthesizes evidence for existing and emerging treatment approaches for obesity-related asthma and highlights pathways that offer potential targets for novel therapeutics. Existing treatments targeting insulin resistance and obesity, including metformin and GLP-1 (glucagon-like-peptide 1) receptor agonists, have been associated with improved asthma outcomes, although GLP-1R agonist data in asthma are limited to individuals with comorbid obesity. Monoclonal antibodies approved for treatment of moderate to severe asthma generally appear to be effective in individuals with obesity, although this is based on retrospective or secondary analysis of clinical trials; moreover, although most of these asthma biologics are approved for use in the pediatric population, the impact of obesity on their efficacy has not been well studied in youth. Potential therapeutic targets being investigated include IL-6, arginine metabolites, nitro-fatty acids, and mitochondrial antioxidants, with clinical trials for each currently underway. Potential therapeutic targets include adipose tissue eosinophils and the GLP-1-arginine-advanced glycation end products axis, although data in humans are still needed. Finally, transcriptomic and epigenetic studies of "obese asthma" demonstrate enrichment of IFN-related signaling pathways, Rho-GTPase pathways, and integrins, suggesting that these too could represent future treatment targets. We advocate for further study of these potential therapeutic mechanisms and continued investigation of the distinct inflammatory pathways characteristic of obesity-related asthma, to facilitate effective treatment development for this unique asthma phenotype.

Association of metformin use with asthma development and adverse outcomes: A systematic review and meta-analysis

BACKGROUND

Asthma and diabetes are prevalent chronic diseases affecting a significant population globally. Research has suggested that metformin, a commonly used medication for diabetes management, may also have beneficial effects in enhancing asthma outcomes. Considering the comorbidity of asthma and diabetes, a comprehensive analysis was performed to investigate the efficacy of metformin in reducing adverse outcomes of asthma patients with diabetes.

METHODS

To gather relevant data, we conducted a systematic search of the PubMed, Embase, and CENTRAL databases for observational studies published prior to September 2023. We specifically looked for studies involving individuals diagnosed with both asthma and diabetes, comparing the incidence and severity of asthma exacerbations in metformin users versus nonusers. The inclusion criteria encompassed studies that recruited participants aged 18 years and older. The primary outcome of interest was the risk of newly developing asthma, while secondary outcomes included the adjusted risk of asthma-induced exacerbations, emergency room visits, and hospitalizations. All data analyses and visualizations were performed using the R programming language.

RESULTS

We identified and included 7 studies involving a total of 1,176,398 patients in our analysis. The pooled effect size indicated a potential reduction in the incidence of newly developed asthma among patients with type 2 diabetes who used metformin, although this finding did not reach statistical significance. Similar conclusions have also been observed in other outcomes, such as exacerbation, asthma-related emergency department visits, risk of systemic corticosteroid prescription. The only positive outcome is that the use of metformin can reduce the chance of patients being hospitalized due to asthma.

CONCLUSION

In most outcome indicators, it cannot be assumed that the use of metformin can reduce asthma-related adverse events. However, the conclusion is not so certain, and longer observation and more evidence are still required. Metformin still shows some potential in the intervention of respiratory diseases.

Metformin and the risks of cellulitis, foot infections, and amputation in patients with type 2 diabetes

BACKGROUND

Patients with diabetes tend to have cellulitis, foot infections, and amputation. We conducted this research to compare the risks of cellulitis, foot infections, and amputation between metformin no-use and use in persons with type 2 diabetes.

METHODS

Using propensity score matching, we identified 23 234 pairs of metformin nonusers and users from the National Health Insurance Research Database of Taiwan, since January 1, 2000, to December 31, 2017. Cox proportional hazards models were adopted to examine the risks of incident cellulitis, recurrent cellulitis, foot infections, and amputation between metformin use and no-use.

RESULTS

The mean follow-up period of metformin use and no-use was 6.31 (3.93) and 5.54 (3.97) years, respectively. Compared with metformin no-use, the adjusted hazard ratio and 95% confidence interval for metformin use in cellulitis development, recurrent cellulitis, foot infections, and amputation were 1.08 (1.04-1.12), 1.33 (1.14-1.55), 1.91 (1.75-2.09), and 1.88 (1.35-2.62), respectively. The longer cumulative duration of metformin usage had association with higher risks of these outcomes than metformin no-use.

CONCLUSION

This population-based cohort study revealed that metformin use had association with significantly higher risks of incident cellulitis, recurrent cellulitis, foot infections, and amputation than metformin no-use in patients with type 2 diabetes.

Management of the pediatric patient with asthma and obesity

Asthma and obesity are 2 of the most significant chronic diseases of childhood. Both are major public health problems that have been increasing in prevalence. Obesity increases the risk of developing asthma in children, and in children with asthma, obesity increases asthma severity and morbidity. The nature of this relationship is complex and not fully understood, but some pediatric patients with "obesity-related asthma" may represent a phenotype that differs from the more classical, atopic pediatric asthma. In this review, we investigate and discuss some of the currently available literature regarding treatment for asthma complicated by obesity in the pediatric population. We cover the importance of healthy lifestyle modifications, management of obesity-related comorbidities, and the potential role of nutritional supplementation or modification. We then review recent literature, mostly in adults, investigating the potential role of obesity or diabetes medications in the management of patients with asthma who have obesity. Finally, we discuss some of the necessary next steps before these potential new treatments can be considered as part of the standard clinical management of asthma.

Metformin and the Risk of Chronic Urticaria in Patients with Type 2 Diabetes

We conducted this study to determine the effect of metformin use on the risk of new-onset chronic urticaria in patients with type 2 diabetes (T2D). In total, 24,987 pairs of metformin users and nonusers were identified with propensity score-matching from Taiwan's National Health Insurance Research Database from 1 January 2000, to 31 December 2017. Multivariable Cox proportional hazards models were used to compare the risks of chronic urticaria development, severe chronic urticaria, and hospitalization for chronic urticaria between metformin users and nonusers. Compared with metformin nonuse, the aHRs (95% CI) for metformin use in chronic urticaria development, severe chronic urticaria, and hospitalization for chronic urticaria were 1.56 (1.39-1.74), 0.40 (0.12-1.30), and 1.45 (0.82-2.56), respectively. The cumulative incidence of chronic urticaria development was significantly higher in metformin users than in nonusers (p < 0.0001). A longer average cumulative duration of metformin use was associated with higher risks of new-onset and hospitalization for chronic urticaria than metformin nonuse. This nationwide cohort study showed that metformin use was associated with a significantly higher risk of chronic urticaria development. A longer average cumulative duration of metformin use was associated with a higher risk of outcomes. More prospective studies are needed to verify our results.