Respiratory and Peripheral Muscle Strength as Predictors of Inhaler Treatment Response in Asthma: A Comparison of DPI and MDI Devices

Bugra Kerget80 enrolled

Overview

Asthma is a chronic respiratory disease characterized by variable airway obstruction. Inhaled therapies are the cornerstone of asthma management, and selecting the appropriate inhaler device is essential for effective treatment. Among available devices, metered dose inhalers (MDIs) and dry powder inhalers (DPIs) are commonly used; however, their effectiveness depends not only on the medication but also on the patient's physiological capacity and inhalation technique. This prospective randomized study aimed to evaluate the factors influencing inhaler treatment response in newly diagnosed asthma patients. A total of 80 patients with at least a high school education, who demonstrated perfect inhaler technique and adherence, were randomly assigned to MDI or DPI groups (n = 40 each). Baseline and one-month follow-up assessments included pulmonary function tests (PFTs), inspiratory and expiratory muscle strength measurements (MIP, MEP), Asthma Control Test (ACT), and handgrip strength (HGS). The study investigated how respiratory and peripheral muscle strength, inspiratory capacity, coordination skills, and clinical status affect treatment outcomes with MDI and DPI. Findings from this research may help guide inhaler selection based on patient-specific physiological characteristics to optimize treatment effectiveness.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Asthma (Diagnosis)

MDI Inhaler TherapyDRUG

Patients in the MDI group received Foster® metered-dose inhaler (MDI) containing beclomethasone dipropionate 100 µg + formoterol fumarate 6 µg per actuation, administered as two puffs twice daily for one month.

DPI Inhaler TherapyDRUG

Patients in the DPI group received Foster® Nexthaler dry powder inhaler (DPI) containing beclomethasone dipropionate 100 µg + formoterol fumarate 6 µg per inhalation, administered as two inhalations twice daily for one month.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: Adults aged ≥ 18 years Newly diagnosed asthma according to GINA guidelines Education level of at least high school Ability to use inhaler devices correctly after standardized training Provided written informed consent to participate Exclusion Criteria: Presence of other chronic lung diseases (e.g., COPD, interstitial lung disease) Acute asthma exacerbation at the time of enrollment Severe neurological or cognitive impairment affecting inhaler use Pregnancy or breastfeeding Refusal or inability to provide informed consent

Outcomes

Primary Outcomes

Change in FEV₁ (%) from Baseline to 1 Month

The primary outcome is the change in forced expiratory volume in one second (FEV₁) expressed as percent of predicted from baseline to one month after initiation of inhaler therapy. Pulmonary function tests were performed according to ATS/ERS 2019 guidelines using the same spirometry device for all participants.

Time frame: Baseline and 1 month after treatment initiation