An observational study in Abdominoplasty, Diaphragm and Respiratory Mechanics, sponsored by Universidade Federal de Pernambuco. Not yet recruiting at 1 site in Brazil. Open to female participants aged Up to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-16.
Sponsored by Universidade Federal de Pernambuco · Observational
The objective of this observational study is to compare parameters of diaphragmatic mechanics, respiratory muscle function, and thoracoabdominal kinematics among women with gastroesophageal reflux disease (GERD) and a history of abdominoplasty, women with a history of abdominoplasty alone, and women with GERD alone, seeking to understand whether the association between these conditions is linked to greater impairment of respiratory function and thoracoabdominal dynamics.
The main question the study aims to answer is: Do women with GERD and a history of abdominoplasty exhibit greater impairment of diaphragmatic mechanics compared to those with a history of abdominoplasty alone and those with GERD alone? Researchers will compare three groups of participants: women with GERD and a history of abdominoplasty, women with a history of abdominoplasty alone, and women with GERD alone to determine whether the coexistence of GERD and abdominoplasty is associated with greater alterations in diaphragmatic mobility and thickness, respiratory muscle strength and endurance, thoracoabdominal kinematics, abdominal core and sternocleidomastoid muscle thickness, and body composition, as well as worse GERD-related symptoms and quality of life.
Participants will undergo an initial clinical assessment, including medical history, anthropometric measurements, and body composition analysis via bioimpedance. They will also complete questionnaires regarding GERD symptoms, quality of life, and physical activity levels. Subsequently, assessments will be performed, including ultrasound of the diaphragm, abdominal muscles, and sternocleidomastoid muscle; spirometry; evaluation of thoracoabdominal kinematics; measurement of respiratory muscle strength via manovacuometry; and a respiratory muscle endurance test. When necessary for the diagnostic confirmation of GERD, 24-hour ambulatory esophageal impedance-pH monitoring will be performed. Upon completion of the assessments, the results obtained will be compared across the three groups to identify potential differences related to the association between GERD and abdominoplasty.
1,086 studies on the registry are indexed under Gastroesophageal Reflux; 187 are open to participants now.
This study's planned enrollment of 30 is below the median of 175 across 304 observational studies indexed under Gastroesophageal Reflux.
Browse Gastroesophageal Reflux studies →Universidade Federal de Pernambuco is the lead sponsor of 166 studies on the registry; 22 are open to participants now.
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The study population will consist of adult women, with and without a diagnosis of GERD and with and without a history of abdominoplasty. After confirmation of eligibility criteria, participants will be assigned to three study groups based on their clinical and surgical characteristics: GERD + abdominoplasty group (GERD+AP), GERD group (GERD), and abdominoplasty group (AP).
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Exclusion Criteria:
Individuals with a diagnosis of GERD confirmed by 24-hour impedance-pH monitoring and a history of abdominoplasty at least 10 years ago.
Other: Assessment of anthropometric and sociodemographic data and clinical history · Other: Assessment of Symptoms, Quality of Life, and Physical Activity · Other: Spirometric assessment · Other: Manovacuometry assessment · Other: Ultrasound Assessment of the Diaphragm, Abdominal Core, and Sternocleidomastoid · Other: Assessment of respiratory muscle endurance · Other: Thoracoabdominal kinematics · Other: Body bioimpedance assessment
Individuals with a diagnosis of GERD confirmed by 24-hour impedance-pH monitoring, without a history of abdominoplasty.
Other: Assessment of anthropometric and sociodemographic data and clinical history · Other: Assessment of Symptoms, Quality of Life, and Physical Activity · Other: Spirometric assessment · Other: Manovacuometry assessment · Other: Ultrasound Assessment of the Diaphragm, Abdominal Core, and Sternocleidomastoid · Other: Assessment of respiratory muscle endurance · Other: Thoracoabdominal kinematics · Other: Body bioimpedance assessment
Individuals with a history of abdominoplasty at least 10 years ago, without suggestive symptoms and with no diagnosis of GERD.
Other: Assessment of anthropometric and sociodemographic data and clinical history · Other: Assessment of Symptoms, Quality of Life, and Physical Activity · Other: Spirometric assessment · Other: Manovacuometry assessment · Other: Ultrasound Assessment of the Diaphragm, Abdominal Core, and Sternocleidomastoid · Other: Assessment of respiratory muscle endurance · Other: Thoracoabdominal kinematics · Other: Body bioimpedance assessment
The initial assessment will be conducted using a standardized form developed by the researchers, covering sociodemographic data (age, sex, ethnicity, education level, occupation), anthropometric data (weight, height, body mass index, waist circumference), a clinical history of symptoms (onset, weekly frequency, time of peak occurrence, triggering factors, use of antacids, psychosocial factors, alarm symptoms, presence of comorbidities, smoking, alcohol consumption, and history of thoracoabdominal surgeries), and a physical examination.
GERD-related symptoms will be assessed using the Gastroesophageal Reflux Disease Symptom Questionnaire (QS-DRGE), which has been validated for the Portuguese language. Disease-related quality of life will be assessed using the GERD-HRQL questionnaire (Appendix B), translated into Portuguese. Physical activity levels will be assessed using the short version of the International Physical Activity Questionnaire (IPAQ), validated for the Portuguese language. Both instruments will be administered individually by a previously trained researcher in a private setting during the initial assessment. Participants will complete the questionnaires via a structured interview, with any questions clarified without influencing the responses.
Pulmonary function will be assessed via spirometry using a Micro Medical MicroLoop MK8 spirometer (England), calibrated daily with a 3-liter syringe in accordance with American Thoracic Society/European Respiratory Society (ATS/ERS) recommendations. The following parameters will be measured: slow vital capacity (SVC), inspiratory capacity (IC), forced vital capacity (FVC), forced expiratory volume in the first second (FEV₁), FEV₁/FVC ratio, and peak expiratory flow (PEF). Tests will be conducted in a suitable environment by a trained evaluator, with participants seated and wearing a nose clip, following instructions and a prior demonstration of the maneuvers. At least three acceptable and reproducible forced expiratory maneuvers will be performed, and the best values obtained will be used. Interpretation will be based on reference equations for the Brazilian population, with biosafety measures implemented throughout the procedure.
Respiratory muscle strength will be assessed via manovacuometry using the MVD 300 U HOMED device, in accordance with American Thoracic Society/European Respiratory Society (ATS/ERS) recommendations. Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) will be measured. Participants will remain seated without back support, with the trunk upright, head in a neutral position, and feet resting on the floor, while using a nose clip and a mouthpiece with an adequate seal. MIP will be obtained following maximal expiration to residual volume, followed by maximal inspiration against an occluded airway, whereas MEP will be measured following maximal inspiration to total lung capacity, followed by forced expiration against the occluded mouthpiece. Three to five acceptable and reproducible maneuvers will be performed, and the highest value obtained will be recorded. Interpretation will be based on reference equations for the Brazilian population.
Diaphragmatic mechanics and the thickness of the abdominal core muscles and sternocleidomastoid will be assessed via ultrasound using a LOGIQ-V2 (General Electric) system. Participants will be positioned in a semi-reclined supine position (30°-45°). A convex transducer (3.5 MHz) will be used to measure diaphragmatic mobility in M-mode, while a linear transducer (7 MHz) will be used to assess diaphragmatic thickness, the thickening fraction, and the thickness of the rectus abdominis, internal and external obliques, transversus abdominis, and sternocleidomastoid muscles in B-mode. Mobility will be recorded during quiet breathing and deep inspiration, whereas muscle thickness will be measured at the end of expiration and at maximal inspiration. At least three consecutive measurements will be performed for each variable, and the mean value will be used. All procedures will follow previously validated protocols and standardized verbal commands to ensure measurement reproducibility.
Inspiratory muscle endurance will be assessed using the POWERbreathe® KH2 (Powerbreathe International Ltd.) with a load set at 60% of the maximal inspiratory pressure (MIP) previously determined via manovacuometry. The test will be conducted in a controlled environment using calibrated equipment and administered by a trained evaluator, following instructions and a demonstration of the technique. Participants will remain seated with their trunks upright, heads in a neutral position, and feet resting on the floor, while using a nose clip and a mouthpiece with a proper seal. Cycles of rapid, vigorous inspiration against resistance,followed by passive expiration,will be performed for up to 10 minutes or until the limit of tolerance is reached. Heart rate and peripheral oxygen saturation will be measured before and after the test. The device will automatically record inspiratory power, energy, inspiratory volume and flow, endurance time, S-Index, peak inspiratory flow, and the number of bre
Thoracoabdominal kinematics will be assessed using optoelectronic plethysmography (OEP BTS Bioengineering®, Milan, Italy) in a room equipped with a system of pre-calibrated, synchronized infrared cameras. Participants will remain seated with an upright trunk and the head in a neutral position, while 89 reflective markers are attached to standardized anatomical landmarks on the chest and abdominal walls. The system will perform a three-dimensional reconstruction of the thoracoabdominal surface and calculate respiratory volumes via mathematical integration. During data acquisition, participants will breathe quietly for 3 minutes. The following parameters will be analyzed: total chest wall volume (Vcw); the volumes of the pulmonary rib cage (Vrc,p), abdominal rib cage (Vrc,a), and abdominal (VAb) compartments; their relative contributions to tidal volume (%Rc and %Ab); and the absolute change in abdominal volume (ΔVAb).
Body composition will be assessed via multifrequency electrical bioimpedance using the InBody 120® to characterize the sample and control for confounding factors. Participants will be instructed to fast for at least four hours; avoid alcohol for the preceding 48 hours; avoid intense physical activity, caffeine, and thermogenic supplements for the preceding 24 hours; maintain their usual hydration; empty their bladder before the test; remove metal objects; and wear light clothing. Assessments will follow the manufacturer's recommendations, with the participant standing barefoot, maintaining proper contact with the electrodes, and resting for five minutes beforehand. Tests involving movement or loss of contact will be repeated. The following variables will be obtained: body fat index, skeletal muscle mass, fat-free mass index, total fat mass, total and segmental body fat percentage, segmental lean mass, waist-to-hip ratio, total body water, and estimated ideal weight.
Diaphragmatic mobility
Time frame: 1 day
Diaphragmatic Thickness
Time frame: 1 day
Diaphragmatic contraction velocity
Time frame: 1 day
Diaphragmatic Thickening Fraction (DTF)
Time frame: 1 day
Forced expiratory volume in the first second (FEV1)
Time frame: 1
Forced vital capacity (FVC)
Time frame: 1 day
FEV1/FVC ratio
Time frame: 1 day
Physical activity level
Time frame: 1 day
Rectus abdominis muscle thickness
Time frame: 1 day
Internal oblique muscle thickness
Time frame: 1 day
External oblique muscle thickness
Time frame: 1 day
Transversus abdominis muscle thickness
Time frame: 1 day
Sternocleidomastoid muscle thickness
Time frame: 1 day
Pulmonary chest wall volume
Time frame: 1 day
Chest wall volume
Time frame: 1 day
Abdominal chest wall volume
Time frame: 1 day
Abdominal volume
Time frame: 1 day
Percentage of the abdominal compartment relative to total tidal volume (%Ab)
Time frame: 1 day
Percentage of the thoracic compartment to the total tidal volume
Time frame: 1 day
Absolute change in abdominal compartment volume
Time frame: 1 day
Estimated ideal weight
Time frame: 1 day
Skeletal muscle mass (SMM)
Time frame: 1 day
Total fat mass (TFM)
Time frame: 1 day
Body fat percentage (%BF)
Time frame: 1 day
Waist-to-hip ratio (WHR)
Time frame: 1 day
Body fat percentage (BFP)
Time frame: 1 day
Fat-free mass index (FFMI)
Time frame: 1 day
Segmental lean mass percentage
Time frame: 1 day
Segmental body fat percentage
Time frame: 1 day
Total Body Water (TBW)
Time frame: 1 day
Inspiratory power
Time frame: 1 day
Total Energy
Time frame: 1 day
Inspired Medium Volume
Time frame: 1 day
Mean inspiratory flow
Time frame: 1 day
Endurance time limit
Time frame: 1 day
Number of breaths
Time frame: 1 day
Peak Inspiratory Flow
Time frame: 1 day
Strenght-INDEX
It is a dynamic and non-invasive measure of inspiratory muscle strength.
Time frame: 1 day
GERD symptom presence score
This variable aims to assess and quantify the intensity and frequency of symptoms related to Gastroesophageal Reflux Disease (GERD), using the Gastroesophageal Reflux Disease Symptom Questionnaire (GERD-SQ), a clinical tool translated and validated for the Portuguese language. The final score is calculated by summing the responses assigned to each question, ranging from 0 to 45 points (where 0 represents the best condition/absence of symptoms and 45 the worst).
Time frame: 1 day
Quality of life score in GERD
This variable will be evaluated using the GERD-HRQL (Gastroesophageal Reflux Disease - Health Related Quality of Life), a validated and widely used questionnaire to measure the severity of Gastroesophageal Reflux Disease (GERD) symptoms and their impact on the patient's quality of life. The score ranges from 0 to 75 points. The higher the score, the worse the symptoms and the greater the impact on quality of life.
Time frame: 1 day
Mean gastroesophageal junction pressure (PmGEJ)
Time frame: 1 day
Number of gastroesophageal reflux episodes
Time frame: 1 day
Acid exposure time
Time frame: 1 day
Peak Expiratory Flow (PEF)
Time frame: 1 day
Maximal inspiratory pressure (MIP)
Time frame: 1 day
Maximal expiratory pressure (MEP)
Time frame: 1 day
Start is estimated for Nov 2026; primary completion for Oct 2027, 11 months later.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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