An observational study in Bronchial Asthma, Vitamin D Deficiency and Pulmonary Function Impairment, sponsored by Sinai University. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-29.
Sponsored by Sinai University · Observational
Asthma is a chronic inflammatory airway disease associated with variable airflow limitation and persistent respiratory symptoms. Vitamin D has been proposed as a potential biomarker related to immune regulation, asthma control, pulmonary function, and oxidative stress balance.
This prospective cross-sectional observational study aims to investigate the association between serum 25-hydroxyvitamin D [25(OH)D] concentrations, asthma control, pulmonary function parameters, and erythrocyte oxidative stress biomarkers among Egyptian adults with bronchial asthma.
A total of 200 adult asthma patients will be recruited from Abbassia Chest Hospital, Cairo, Egypt. Participants will undergo clinical assessment, Asthma Control Test (ACT), post-bronchodilator spirometry, serum vitamin D measurement, and oxidative stress biomarker assessment including malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), and reduced glutathione (GSH).
Participants will be categorized according to serum 25(OH)D concentrations into vitamin D deficient, insufficient, and sufficient groups.
No intervention or treatment assignment will be performed.
5. Detailed Description
This single-center cross-sectional observational study is designed to evaluate the association between serum vitamin D status and asthma-related clinical, functional, and biochemical characteristics among adult patients with bronchial asthma.
Eligible participants will be adults aged 18 years or older with confirmed bronchial asthma who are clinically stable at the time of assessment. Participants will be recruited from Abbassia Chest Hospital, Cairo, Egypt.
After obtaining written informed consent, demographic and clinical characteristics will be collected, including age, sex, body mass index (BMI), smoking status, asthma duration, previous exacerbations, hospitalization history, asthma severity, and current asthma medications including inhaled corticosteroids (ICS), long-acting β2 agonists (LABA), and short-acting β2 agonists (SABA).
Asthma control will be assessed using the Asthma Control Test (ACT), which evaluates symptom frequency, rescue medication use, activity limitation, and patient perception of asthma control.
Pulmonary function will be evaluated using post-bronchodilator spirometry according to ATS/ERS recommendations. The recorded parameters will include forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio.
Blood samples will be collected for serum 25(OH)D measurement using the DiaSorin LIAISON® 25 OH Vitamin D chemiluminescent immunoassay and assessment of oxidative stress biomarkers in erythrocyte hemolysates, including MDA, SOD, GPx, and GSH.
Participants will be classified according to vitamin D status:
Vitamin D deficient: \<20 ng/mL Vitamin D insufficient: 20-30 ng/mL Vitamin D sufficient: >30 ng/mL
The primary objective is to determine whether serum vitamin D concentration is associated with asthma control. Secondary objectives include evaluating associations with pulmonary function and oxidative stress biomarkers.
4,843 studies on the registry are indexed under Asthma; 602 are open to participants now.
This study's planned enrollment of 134 is below the median of 158 across 1,251 observational studies indexed under Asthma.
Browse Asthma studies →Sinai University is the lead sponsor of 24 studies on the registry; 11 are open to participants now.
Counted across the registry records on this site, refreshed daily.
The study population will consist of 200 adult patients with confirmed bronchial asthma recruited from Abbassia Chest Hospital, Cairo, Egypt. Eligible participants will be adults aged ≥18 years with stable asthma at the time of assessment. Participants will be categorized according to serum 25-hydroxyvitamin D [25(OH)D] concentrations into vitamin D deficient (\<20 ng/mL), vitamin D insufficient (20-30 ng/mL), and vitamin D sufficient (>30 ng/mL) groups. Clinical characteristics, asthma control, pulmonary function, serum vitamin D status, and erythrocyte oxidative stress biomarkers will be assessed during a single study visit.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adults with bronchial asthma and serum 25-hydroxyvitamin D concentrations below 20 ng/mL.
Adults with bronchial asthma and serum 25-hydroxyvitamin D concentrations between 20 and 30 ng/mL.
Adults with bronchial asthma and serum 25-hydroxyvitamin D concentrations above 30 ng/mL.
Asthma Control Level Measured by Asthma Control Test (ACT) Score
Assessment of asthma control using the Asthma Control Test (ACT) questionnaire, reported as an ACT score ranging from 0 to 25 points.
Time frame: Single baseline assessment.
Pulmonary Function Parameters
FEV1 % predicted FVC % predicted FEV1/FVC ratio
Time frame: Single baseline assessment.
Oxidative Stress Biomarkers
Malondialdehyde (MDA) Superoxide dismutase (SOD) Glutathione peroxidase (GPx) Reduced glutathione (GSH)
Time frame: Single baseline assessment.
Serum Vitamin D Concentration
Serum 25-hydroxyvitamin D concentration (ng/mL)
Time frame: Single baseline assessment.
No study locations are listed for this record.
Plan to share: No — Individual participant data will not be publicly shared. The datasets contain potentially identifiable health information, and participant consent and institutional ethical approval did not include unrestricted public data sharing. Reasonable requests for access to de-identified data may be considered by the corresponding author, subject to institutional and ethical approval.
No publications or documents are linked to this record.
Start is estimated for Jul 2026; primary completion for Dec 2026, 5 months later.
Of 364 non-industry observational studies under Asthma, half reached primary completion within 38 months of starting (the median), counting those still running; a quarter within 18 and three quarters within 97. This study's planned 5 months is below that.
Counting every sponsor, half of 454 studies reached it within 36 months; a quarter within 18 and three quarters within 82.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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Sinai University