Prediction Models for Dynamic Respiratory Muscle Strength in COPD and Asthma Patients Based on Constant-Pressure Inspiratory Muscle Performance
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 123
- 试验地点
- 1
- 主要终点
- Dynamic Inspiratory Muscle Strength Assessed by S-Index
研究概览
简要总结
This observational study evaluates whether dynamic inspiratory muscle strength can be estimated in patients with chronic obstructive pulmonary disease (COPD) and asthma using simple clinical and performance-based measurements. Dynamic inspiratory muscle strength was assessed using the S-Index, which reflects the pressure generated during a fast and forceful inspiration while airflow is maintained.
The study included adult male patients diagnosed with COPD or asthma. Participants completed respiratory muscle strength assessment, pulmonary function testing, body composition assessment, and a fixed-pressure inspiratory muscle performance test using a threshold loading device set at 30 cmH₂O. The number of inspiratory repetitions performed until task failure and related respiratory variables were recorded.
The main aim of the study was to develop prediction models for estimating S-Index values from accessible measures such as peak inspiratory flow, inspiratory repetition performance, spirometry parameters, and body composition variables. The study may help determine whether dynamic inspiratory muscle strength can be estimated in clinical settings where direct S-Index measurement devices are not available.
详细描述
Dynamic inspiratory muscle strength provides important information about the functional capacity of the inspiratory muscles. In patients with chronic respiratory diseases such as COPD and asthma, respiratory muscle function may be affected by airflow limitation, altered ventilatory mechanics, dyspnea, and reduced exercise tolerance. Although maximal inspiratory pressure is commonly used to assess respiratory muscle strength, it mainly reflects static pressure-generating capacity. The S-Index is a dynamic measure obtained during a rapid and forceful inspiratory maneuver and may provide additional information about inspiratory muscle performance under flow-dependent conditions.
This study was designed as an observational, cross-sectional predictive modeling study. Adult male patients with a clinical diagnosis of COPD or asthma were prospectively recruited from clinical units of Çorum Erol Olçok Training and Research Hospital, Hitit University, Türkiye. All participants provided informed consent before participation. The study was approved by the Hitit University Non-Interventional Research Ethics Committee.
Participants attended a familiarization session before the measurement day. During this session, the study procedures were explained, the measurement techniques were demonstrated, and participants were informed about behaviors to avoid before testing. On the measurement day, demographic information was recorded, and participants underwent dynamic inspiratory muscle strength assessment, body composition assessment, pulmonary function testing, and a fixed-pressure inspiratory muscle performance test.
The S-Index was measured using the POWERbreathe K5 device in single-breath test mode. Participants were instructed to exhale fully to residual volume and then perform the fastest and strongest possible inspiration through the device until the lungs were completely filled. Multiple trials were performed, and the highest S-Index value was used for analysis.
Pulmonary function testing was performed using standardized spirometry procedures. Forced vital capacity, forced expiratory volume in one second, the FEV1/FVC ratio, peak expiratory flow, peak inspiratory flow rate, and inspiratory volume were recorded. Body composition variables, including body weight, body mass index, fat-free mass, fat mass, and body fat percentage, were assessed using multi-frequency bioelectrical impedance analysis.
研究设计
- 研究类型
- Observational
- 观察模型
- Other
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- Male
- 接受健康志愿者
- 否
入选标准
- •Being 18 years of age or older
- •Having a clinical diagnosis of chronic obstructive pulmonary disease or asthma
- •Being able to perform fixed-pressure inspiratory muscle loading and S-Index measurements in accordance with the instructions and with correct technique
- •Having experienced no additional clinical condition within the previous 12 weeks, apart from the existing chronic respiratory disease, that could acutely affect respiratory function
- •Having signed the informed consent form approved by the ethics committee
排除标准
- •Inability to perform fixed-pressure inspiratory muscle loading or dynamic respiratory muscle strength assessment according to the technical requirements of the measurement protocols
- •Inability to obtain reliable data due to insufficient coordination, motivation, or volitional effort
- •Presence of a musculoskeletal injury or surgical history affecting the diaphragm, thorax, spine, or abdominal region that could significantly impair respiratory mechanics
- •Presence of neurological conditions that may affect respiratory muscle function, such as neuromuscular diseases, peripheral nerve damage, or central nervous system disorders
研究组 & 干预措施
Asthma Patients
Adult male patients with a clinical diagnosis of asthma who underwent dynamic inspiratory muscle strength assessment, spirometry, body composition assessment, and fixed-pressure inspiratory muscle performance testing.
COPD Patients
Adult male patients with a clinical diagnosis of chronic obstructive pulmonary disease who underwent dynamic inspiratory muscle strength assessment, spirometry, body composition assessment, and fixed-pressure inspiratory muscle performance testing.
结局指标
主要结局
Dynamic Inspiratory Muscle Strength Assessed by S-Index
时间窗: Day 1, during the single assessment visit
Dynamic inspiratory muscle strength was assessed using the S-Index measured with the POWERbreathe K5 device in single-breath test mode. Participants performed maximal and rapid inspiratory efforts after full expiration to residual volume. The highest S-Index value obtained from repeated maximal inspiratory efforts was recorded in cmH₂O.
次要结局
- Number of Inspiratory Repetitions to Task Failure(Day 1, during the single assessment visit)
- Time to Task Failure During Fixed-Pressure Inspiratory Loading(Day 1, during the single assessment visit)
- Forced Vital Capacity(Day 1, during the single assessment visit)
- Forced Expiratory Volume in One Second(Day 1, during the single assessment visit)
- FEV1/FVC Ratio(Day 1, during the single assessment visit.)
- Peak Expiratory Flow(Day 1, during the single assessment visit.)
- Inspiratory Volume(Day 1, during the single assessment visit.)
- Secondary Outcome Measure 7(Day 1, during the single assessment visit.)
研究者
Mehmet İsmail TOSUN
Assistant Professor
Hitit University