Inspiratory Muscle Training Improves Cough Strength in Frail Older Adults

A recent randomized controlled trial has shown that inspiratory muscle training (IMT) significantly enhances cough strength in older adults with frailty, suggesting its potential as a targeted intervention for this vulnerable population.

The study involved 60 frail older adults, with 52 completing the trial. Participants were randomly assigned to either an IMT group, which performed inspiratory muscle exercises alongside general exercise training, or a control group that engaged in general exercise training alone. 

IMT participants used a threshold device set at 30% of their maximum inspiratory pressure, performing 30 breaths twice daily over eight weeks.

The primary outcome, cough peak flow (CPF), demonstrated notable improvement in the IMT group, with an average increase of 28.7 ± 44.4 L/min compared to a decrease of -7.4 ± 26.6 L/min in the control group. The mean difference between groups was 36.3 L/min (95% CI: 16.7–55.9), with a large effect size of 0.99.

These findings indicate that IMT is a practical and effective approach to strengthening respiratory muscles, leading to improved cough function in frail older adults. Enhanced cough strength can play a critical role in reducing the risk of complications such as aspiration and respiratory infections, offering a valuable addition to care strategies for this demographic.
 

Gefapixant Reduces Cough-Induced Stress Urinary Incontinence in Women with Chronic Cough

A phase 3b randomized controlled trial has demonstrated that gefapixant significantly reduces episodes of cough-induced stress urinary incontinence (CSUI) in women with refractory or unexplained chronic cough, marking a breakthrough in treating this challenging condition.

The study included 375 women aged 18 and older with chronic cough lasting at least one year and CSUI persisting for over three months.

Participants were randomized to receive gefapixant 45 mg twice daily or placebo for 12 weeks. The primary outcome was the percentage change in daily CSUI episodes over seven days at week 12.

Results showed a -52.8% reduction in CSUI episodes with gefapixant compared to -41.1% with placebo, yielding an estimated treatment difference of -11.7% (P = 0.004).

Gefapixant also demonstrated consistent safety, with the most common adverse events being taste-related disturbances. Adverse events occurred in 70% of the gefapixant group compared to 37% in the placebo group, aligning with prior studies of the drug.

This trial establishes gefapixant as the first treatment to demonstrate efficacy in reducing CSUI episodes among women with chronic cough, addressing a significant unmet medical need. The findings highlight gefapixant’s potential as a dual-action therapy, improving both chronic cough and its impact on urinary health, with a manageable safety profile.

Indoor Radon Decay Products Linked to Increased Cough and Phlegm in COPD Patients

A recent study highlights the association between exposure to radon decay products, measured as particle radioactivity (PR), and worsening respiratory symptoms in patients with chronic obstructive pulmonary disease (COPD).

The study involved 141 male former smokers with COPD who participated in up to four one-week seasonal assessments. Researchers measured indoor and ambient particulate matter (PM2.5) and black carbon (BC), alongside PR levels, using α-radiation activity on PM2.5 filters.

Respiratory symptoms, including cough, phlegm, and shortness of breath, were evaluated through the St. George’s Respiratory Questionnaire (SGRQ), which also assessed health-related quality of life (HRQL).

Results revealed that indoor radon decay products were significantly associated with increased cough (31.1% per interquartile range [IQR], 95% CI: 8.8%–57.8%) and suggestively associated with phlegm (13.0% per IQR, 95% CI: -2.5%–31.0%).

A modest increase in SGRQ symptom scores (1.2 units per IQR, 95% CI: -0.3–2.6) was also observed, though it did not reach statistical significance. These effects persisted after adjusting for indoor PM2.5 and BC.

The findings underscore the impact of indoor radon decay exposure on respiratory health in COPD patients, emphasizing the need for improved indoor air quality to mitigate symptom severity and enhance quality of life in this vulnerable population.

Diaphragmatic Breathing Significantly Improves Chronic Cough in GERD Patients

A randomized controlled trial has demonstrated that deep diaphragmatic breathing (DEP) training significantly enhances treatment outcomes for patients suffering from gastroesophageal reflux-induced chronic cough (GERC). 
Sixty patients were divided into two groups: one receiving standard medication for GERC and the other undergoing additional DEP training.
After eight weeks, both groups experienced symptom improvement, but the intervention group, which practiced DEP, showed a markedly higher cough resolution rate (94%) compared to the control group (77%, p = 0.041). 
DEP training also resulted in significantly better scores in the gastroesophageal reflux diagnostic questionnaire (GerdQ), generalized anxiety disorder scale (GAD-7), Pittsburgh sleep quality index (PSQI), and Leicester cough questionnaire (LCQ). Importantly, patients who practiced DEP displayed improved diaphragmatic muscle activity, measured by surface electromyography (sEMG), during both deep and quiet breathing.
This research highlights the therapeutic potential of diaphragmatic breathing as a valuable adjunct to standard medical treatment for GERC patients. Improvements in cough symptoms, anxiety levels, sleep quality, and overall quality of life suggest that DEP training may offer a non-invasive, low-cost approach to managing chronic cough caused by gastroesophageal reflux disease. 
These findings provide a strong rationale for incorporating breathing exercises into the management plans for patients with GERC, enhancing symptom control beyond conventional treatments alone.
 

Chronic Cough Triggers Vary by Etiology and Are Only Partially Linked to Capsaicin Sensitivity

A comprehensive study has revealed the diverse profile of cough triggers in chronic cough patients and their limited correlation with capsaicin cough sensitivity.  
In a cross-sectional analysis of 1,211 patients with chronic cough, 91.4% reported experiencing at least one trigger. Chemical triggers were most prevalent (66.9%), followed by thermal exposure (50.6%), mechanical triggers (48.2%), and meal-related triggers (21.2%). 
While chemical triggers were consistent across different cough etiologies, meal and mechanical triggers were more common in refractory chronic cough, with meal triggers particularly associated with gastroesophageal reflux-related cough.  
Refractory chronic cough patients reported the highest prevalence of triggers (97.1%). Capsaicin challenge tests conducted on 254 participants showed a mild correlation between the number of triggers, particularly chemical ones, and capsaicin cough sensitivity. However, these findings suggest that cough hypersensitivity in chronic cough encompasses a broader spectrum of mechanisms beyond capsaicin sensitivity.  
The study highlights the need for personalized approaches in managing chronic cough, considering the varied triggers and their etiology-specific profiles.