A Phase 4 interventional study of Continuous positive airway pressure and Conventional pharmacological treatment in Sleep Apnea, Obstructive and Polycythemia, sponsored by Hospital Universitario Ramon y Cajal. Recruiting at 1 site in Spain. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2025-09-17.
Sponsored by Hospital Universitario Ramon y Cajal · Phase 4, Interventional, and Treatment
Objectives: To compare the response of polycythemia in terms of hematocrit decrease in patients treated with positive airway pressure (CPAP) versus patients not treated with CPAP.
Methodology: Randomized, parallel-group, nonblinded, controlled clinical trial.
Patients diagnosed with OSA in a respiratory polygraphy (RP) and who meet all the inclusion criteria and none of the exclusion criteria will undergo sleepiness and quality of life questionnaires, anthropometric measurements and blood tests and will be randomized to a CPAP treatment group or control group, maintaining this treatment for 12 months. A visit will be made at 12 weeks ,24 weeks and 52 weeks to check compliance with CPAP in the treatment group and to carry out questionnaires on physical activity and quality of life, anthropometric measurements, blood tests including hemoglobin and hematocrit as well as parameters related to coagulation and platelet function and changes in medication as well as adverse effects.
Efficacy variables: blood count, hemoglobin, haematocrit, erythropoietin, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), mean platelet volume (MPV), platelets, coagulation, erythrocyte range of distribution (ADE), glucose, creatinine, glomerular filtration rate, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (GGT), Total bilirubin, hypoxic burden, Epworth score, EuroQol- 5D questionnaire.
2,240 studies on the registry are indexed under Sleep Apnea, Obstructive; 475 are open to participants now.
This study's planned enrollment of 182 is above the median of 52 across 1,472 interventional studies indexed under Sleep Apnea, Obstructive.
Browse Sleep Apnea, Obstructive studies →Hospital Universitario Ramon y Cajal is the lead sponsor of 30 studies on the registry; 3 are open to participants now.
Counted across the registry records on this site, refreshed daily.
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.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
FEV1
From a breathing test (spirometry): how much air you can blow out in the first second. Often given as a percentage of what is expected for your age, height and sex.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
TIA (transient ischaemic attack)
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Diet and conventional pharmacological treatment plus continuous positive airway pressure (CPAP)
Device: Continuous positive airway pressure · Drug: Conventional pharmacological treatment · Other: Sleep ,diet and life style recomendations
Diet and conventional pharmacological treatment
Drug: Conventional pharmacological treatment · Other: Sleep ,diet and life style recomendations
Nocturnal continuous positive airway pressure by a nasal mask. CPAP pressure will be automatically titrated using a AutoSet device (ResMed)
Also known as: CPAP
Usual treatment of the patient
Daily recomendatios
Also known as: Conventional recomendations
Change from baseline of hematocrit
To compare the change in hematocrit in blood patients between the patients allocated to CPAP group and the control group
Time frame: 12 months
Change from baseline of hemoglobin
To compare the change in hemoglobin in blood patients between the patients allocated to CPAP group and the control group
Time frame: 12 months
Change from baseline in the health-related quality of life assessed by the Euroqol-5
The 5-level EQ-5D version (EQ-5D-5L) essentially consists of 2 pages: the EQ-5D descriptive system and the EQ visual analogue scale (EQ VAS). The descriptive system comprises five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 levels: no problems, slight problems, moderate problems, severe problems and extreme problems. The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. This decision results in a 1-digit number that expresses the level selected for that dimension. The digits for the five dimensions can be combined into a 5-digit number that describes the patient's health state. The EQ VAS records the patient's self-rated health on a vertical visual analogue scal fom 0 to 100 points.
Time frame: 12 months
Relationship between hypoxic burden and hemoglobin and hematocrit
HB was defined as the total area under the oxygen saturation curve from a pre-event baseline oxygen desaturation. For each apnea and hypopnea the termination of the event is called "time-zero". The oxygen saturation signals around time-zero are synchronized with respect to time-zero.The time-aligned oxygen saturation signals are ensemble-averaged such that the mean value at each time point is calculated, resulting in a subject-specific average oxygen saturation curve specific to apneas and hypopneas.A subject-specific search window to quantify the area under the desaturation curve for each event is defined as the interval between the pre-event and post-event maximum oxygen saturation values. This time-locked search window will be used to determine the start and end of oxygen desaturation and calculate the area under desaturation curve for each respiratory event.Total HB (%min/h) is defined as the sum of individual areas (%min) divided by total sleep time (h).
Time frame: 12 months
Change from baseline in sleepiness assessed by Epworth scale
To compare the change in the total score and the domains of the Epworth sleepiness scale between the CPAP group and the control group. The ESS is a self-administered questionnaire with 8 questions. Respondents are asked to rate, on a 4-point scale (0-3), their usual chances of dozing off or falling asleep while engaged in eight different activities. Interpretation: 0-7:It is unlikely that you are abnormally sleepy. 8-9:You have an average amount of daytime sleepiness. 10-15:You may be excessively sleepy depending on the situation. You may want to consider seeking medical attention. 16-24:You are excessively sleepy and should consider seeking medical attention.
Time frame: 12 months
Relationship between night time below SaO2 90% (T90) and oxygen desaturation index (ODI) and hematocrit
T90 is the percent sleep time with SpO2 below 90%. T90 measures the desaturations that dip below a threshold of 90%. Oxygen desaturation index (ODI) is the average number of desaturation episodes per hour. It is used to characterize intermittent hypoxemia (IH), an OSA-related physiological consequence that is likely responsible for most of the pathophysiological systemic complications of OSA
Time frame: 12 months
Plan to share: No
No publications or documents are linked to this record.
Started Nov 2023 (actual). Primary completion is estimated for Sep 2026, 34 months after the start.
Of 28 non-industry phase 4 interventional studies under Sleep Apnea, Obstructive, half reached primary completion within 26 months of starting (the median), counting those still running; a quarter within 18 and three quarters within 35. This study's planned 34 months is above that.
Counting every sponsor, half of 31 studies reached it within 26 months; a quarter within 17 and three quarters within 35.
How these figures are worked out, and which studies are left out of them.
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Hospital Universitario Ramon y Cajal