Nyenhuis, Sharmilee Maria

Abstract RATIONALE: 4G4G/4G5G SERPINE1 genotypes produce high concentrations of plasminogen activator inhibitor-1 and are associated with worse asthma outcomes. A secondary analysis of the American Lung Association (ALA) SOYA trial showed that soy isoflavones significantly reduced asthma exacerbations versus placebo among patients with 4G4G/4G5G SERPINE1 genotypes. We hypothesized that baseline characteristics predict optimal responders to soy isoflavones among this subgroup. METHODS: ALA-SOYA was a randomized controlled trial that tested the efficacy of soy isoflavones vs. placebo for reducing asthma exacerbations among adolescents and adults with symptomatic asthma. In this responder analysis among participants with 4G4G/4G5G SERPINE1 genotypes, baseline demographic and clinical characteristics were tested for effect modification of the treatment assignment (soy/placebo) on the primary outcome of annualized number of asthma exacerbations using interaction terms in negative binomial regression models, with a significance threshold of p-interaction=0.15. RESULTS: Data were available for n=168 participants. Soy reduced the annualized number of asthma exacerbations relative to placebo among patients with 4G4G/4G5G SERPINE1 genotypes (incident rate ratio (IRR)=0.37, 95% confidence interval (CI): 0.15-0.90, p=0.028). Self-reported adherence to baseline controller therapy was the only significant effect modifier of this association (interaction p=0.115), with those using inhaled corticosteroid (ICS)/long-acting beta-agonist (LABA) controller therapy at least twice weekly experiencing reductions in asthma exacerbations with soy versus placebo (IRR = 0.25, 95% CI: 0.09-0.69; p= 0.007) but not among those using ICS/LABA controller therapy less frequently (IRR = 1.33, 95% CI: 0.22-8.02; p= 0.757). CONCLUSION: Soy isoflavones reduce asthma exacerbations among patients with the 4G4G/4G5G SERPINE1 genotypes and are most effective in those with greater adherence to asthma controller therapy regimens.

Importance The optimal inhaled reliever therapy for asthma remains unclear. Objective To compare short-acting β agonists (SABA) alone with SABA combined with inhaled corticosteroids (ICS) and with the fast-onset, long-acting β agonist formoterol combined with ICS for asthma. Data Sources The MEDLINE, Embase, and CENTRAL databases were searched from January 1, 2020, to September 27, 2024, without language restrictions. Study Selection Pairs of reviewers independently selected randomized clinical trials evaluating (1) SABA alone, (2) ICS with formoterol, and (3) ICS with SABA (combined or separate inhalers). Data Extraction and Synthesis Two reviewers independently extracted data and assessed risk of bias. Random-effects meta-analyses synthesized outcomes. GRADE (Grading of Recommendations Assessment, Development, and Evaluation) was used to evaluate the certainty of evidence. Main Outcomes and Measures Asthma symptom control (5-item Asthma Control Questionnaire; range, 0-6, lower scores indicate better asthma control; minimum important difference [MID], 0.5 points), asthma-related quality of life (Asthma Quality of Life Questionnaire; range, 1-7, higher scores indicate better quality of life; MID, 0.5 points), risk of severe exacerbations, and risk of serious adverse events. Results A total of 27 randomized clinical trials (N = 50 496 adult and pediatric patients; mean age, 41.0 years; 20 288 male [40%]) were included. Compared with SABA alone, both ICS-containing relievers were associated with fewer severe exacerbations (ICS-formoterol risk ratio [RR], 0.65 [95% CI, 0.60-0.72]; risk difference [RD], −10.3% [95% CI, −11.8% to −8.3%]; ICS-SABA RR, 0.84 [95% CI, 0.73-0.95]; RD, −4.7% [95% CI, −8.0% to −1.5%]) with high certainty. Compared with SABA alone, both ICS-containing relievers were associated with improved asthma control (ICS-formoterol RR improvement [MID] in total score, 1.07 [95% CI, 1.04-1.10]; RD, 4.1% [95% CI, 2.3%-5.9%]; ICS-SABA RR, 1.09 [95% CI, 1.03-1.15]; RD, 5.4% [95% CI, 1.8%-8.5%]) with high certainty. In an indirect comparison with ICS-SABA, ICS-formoterol was associated with fewer severe exacerbations (RR, 0.78 [95% CI, 0.66-0.92]; RD, −5.5% [95% CI, −8.4% to −2.0%]) with moderate certainty. Compared with SABA alone, ICS-formoterol (RD, −0.6% [95% CI, −1.3% to 0%]) was not associated with increased risk of serious adverse events (high certainty) and ICS-SABA (RD, 0% [95% CI, −1.1% to 1.2%]) was not associated with increased risk of serious adverse events (moderate certainty). Conclusions and Relevance In this network meta-analysis of patients with asthma, ICS combined with formoterol and ICS combined with SABA were each associated with reduced asthma exacerbations and improved asthma control compared with SABA alone.