Sleep Apnea, ObstructiveNCT04444778
Intermitent Hypoxia and Its Pathophysiology Consequences in the Sleep Apnea-Hypopnea Syndrome.
A study testing CPAP in people with Sleep Apnea, Obstructive, run by Alberto Alonso Fernandez at 2 sites in Spain.
Trial summary
Clinical trial on the effect of continuous positive pressure (CPAP). Objectives: 1) To assess the total or partial recovery of oxidative and inflammatory damage after recovering IH. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Sleep Apnea, Obstructive
- What is being tested?
- CPAP
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 130 participants
- Where
- 2 sitesSpain
- Study dates
- 20 Jul 2020to 2 Oct 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Cases: patients with AHI > 30
- Controls: subjects with AHI < 5 and Epworth >10
Who cannot join
- Epworth>18
- BMI<40Kg/M2
- Arterial Hypertension
- Mellitus Diabetes
- Cerebrovascular disease
- Ischemic heart disease
Show all 13Show fewer
- Cardiac arrhythmia
- Chronic cardiovascular diseases
- Daytime Oxygen saturation>95%
- Risk professions (professional drivers)
- Concomitant treatment with antihypertensives, statins, antidiabetics, beta-blockers or systemics corticosteroids.
- Pretreatment with CPAP.
- Participation in another clinical trial thirty days prior to randomization
Trial locations and contacts
2 sites in 1 country.
Spain2 sites
Hospital Son Espases
Palma, Balearic Islands, 07006
Hospital Son Llatzer
Palma, Balearic Islands, 07006
About this study
Official title: Intermitent Hypoxia and Its Pathophysiology Consequences in the Sleep Apnea-Hypopnea Syndrome. Basic, Clinical and Therapeutically Study.
Clinical trial on the effect of continuous positive pressure (CPAP). Objectives: 1) To assess the total or partial recovery of oxidative and inflammatory damage after recovering IH. 2) To check whether the results obtained in vitro on the recovery of the damage according to the form of manifestation of IH are validated in SAHS patients. 3) To determine if CPAP reduces nighttime blood pressure and arterial stiffness depending on whether or not patients have a non-dipping pattern of blood pressure and depending on the degree of correction of IH. 4) To clarify whether residual nocturnal hypoxemia influences the recovery of oxidative and inflammatory damage in patients. 5) To determine nasal and intestinal microbioma and the effect of CPAP treatment
Read the detailed description
Design: Randomized, parallel group, non-blinded, controlled clinical trial compared with conventional treatment.
- Protocol and intervention Patients with an AHI>30 h-1 will be assigned, using a 1:1 randomization table, to lifestyle recommendations treatment or to lifestyle recommendations plus nasal CPAP, for a period of 4 months. CPAP pressure will be titled with automatic using an AutoSet II device, ResMed.
- Sample size For the estimation of the sample size, previous data from our group were used. In this case, in order to compare the effect of CPAP in a subgroup of patients with well-controlled OSA and in another with residual hypoxemia; it would be necessary to randomize a total of 100 patients with OSA.
- Ethical considerations
- Indication of CPAP treatment for the prevention of cardiovascular morbidity and mortality in OSA patients without daytime sleepiness is not yet accepted.
- Those patients with a urgent study indication for the diagnosis and treatment of respiratory sleep disorders (professional drivers, respiratory failure or risk professions) will be excluded from the project. In the other cases, the delay in healthcare for the performance of Polysomnography and CPAP titration exceeds the duration of the study, therefore that patients assigned to the control arm (conventional treatment) will not be exposed to a higher risk than the general population.
- Methods
- Polysomnography. It will be used as a screening test previous the randomization of the included patients. The exploration and its interpretation will be carried out following the recommendations of the American Academy of Sleep Medicine. Based on the results of this test, only those patients with an AHI will continue in the study when AHI >30 h-1. In these patients the determinations listed below will be carried out immediately before randomization (visit 1), at 4 weeks (visit 2), 16 weeks (visit 4) of allocation to the corresponding treatment group
- Clinical data: The medication used and other associated diseases already diagnosed will be recorded.
- Vital signs: recording of blood pressure, by means of a conventional triple taking, and heart rate.
- Anthropometric characteristics: age and weight in basal conditions, the perimeter of the neck and waist / hip index will be measured. The lean mass index will be determined using a Bodystat 1500 impedance system (Bodystat Ltd, United Kingdom).
- Questionnaires: Epworth Sleepiness Scale, generic health-related quality of life (SF-12 and EuroQoL) and daily physical activity (International Physical Activity Questionnaire or iPAQ).
- Laboratory findings: blood count, coagulation, creatinine, serum sodium and potassium; glycated hemoglobin (HbA1c) and blood glucose and insulin levels in fasting, from these values will determine the resistance and sensitivity to insulin using the HOMA and QUICKI indices; total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides; and troponin I, homocysteine, NT-pro BNP and highly sensitive C-reactive protein.
- Blood venous samples. 20 mL of venous blood will be collected, storing the plasma obtained at -80 ºC for subsequent determination of inflammatory markers (IL-1ß, IL-6, IL-8, HIF 1- a and TNF-a), oxidative stress (8-isoprostane), endothelial damage (endothelin, angiotensin), and appetite-regulating hormones (leptin and adiponectin).
- Plasma proteins from peripheral blood samples will be analyzed using a high-throughput multiplex immunoassay technology based on the Proximity Extension Assays (PEA) (OLINK Bioscience, Uppsala, Sweden). Olink (OLINK Bioscience, Uppsala, Sweden).
- Night pulse oximetry. To assess the existence of residual nocturnal hypoxemia.
- Arterial stiffness. According to the recommendations by Sphygmo-Corsystem (version 7, AtCor Medical, Sydney, Australia).
- Study of the gut and pharyngeal microbiota by massive sequencing (next generation sequencing) after PCR amplification of the 16S rRNA gene, paired-end sequencing with Illumina technology (16S Amplicon and XT Nextera Metagenomic) and subsequent metataxonomic analysis of the microbial populations.
- Ambulatory blood pressure monitoring (ABPM) with Mortara's Ambulo 2400 ambulatory blood pressure device.
- In the patients assigned to the CPAP treatment arm, a count of the hours of use of the CPAP will be carried out at each visit by directly reading the automatic counter of each equipment.
Statistic analysis The data will be expressed as mean ± standard deviation, median (interquartile range) or percentage, depending on their type and distribution. For comparison between groups Student's t-test, the U-Mann-Whitney or the chi-square test will be used, as appropriate. The relations between variables will be analyzed using Pearson's correlation and multiple linear regression analysis. The effect of treatment will be evaluated using analysis of covariance (ANCOVA) to compare the change in log-transformed 8-isoprostane for the CPAP versus the usual care group, with the treatment group as a factor, and baseline 8-isoprostane, body mass index, smoking, and age as covariates. Intention-to-treat analysis included all randomized patients, whereas the per-protocol analysis set was defined as all patients in the full analysis who completed the study and, in the group treated with CPAP, achieved adherence greater than 4 hours per night. A multiple logistic regression model will be applied to determine the related variables with a response to treatment. Values of p <0.05 will be considered statistically significant. The statistical study will be performed with the SPSS program version 15.0.
- Conditions
- Sleep Apnea, Obstructive
- Being tested
- CPAP
- Keywords
- sleep apnea syndrome
- Medical subject headings
- Sleep Apnea, Obstructive, Sleep Apnea Syndromes
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CPAPDevice
Continuous positive airway pressure
| Study group | Role | What they receive |
|---|---|---|
| Continuous positive airway pressure | Active comparator | Diet and general life style recommendations plus continuous positive airway pressure (CPAP). Receives: Device: CPAP |
| Conservative treatment | No intervention | Diet and general life style recommendations. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline in 8 isoprostane levels
To compare the change in 8 isoprostane levels between the patients allocated to CPAP group and the control group
Measured: 4 months
Change from baseline in microbiota population diversity from stool samples
To compare the change in in microbiota population diversity, after massive sequencing and amplification of the 16S rRNA gene from stool samples between the patients allocated to CPAP group and the control group
Measured: 4 months
Change from baseline in microbiota population diversity from nasopharyngeal samples
To compare the change in microbiota population diversity, after massive sequencing and amplification of the 16S rRNA gene from nasopharyngeal samples between the patients allocated to CPAP group and the control group
Measured: 4 months
Change from baseline in microbiota population abundance from stool samples
To compare the change in microbiota population abundance, after massive sequencing and amplification of the 16S rRNA gene from stool samples between the patients allocated to CPAP group and the control group
Measured: 4 months
Change from baseline in microbiota population abundance from nasopharyngeal samples
To compare the change in microbiota population abundance, after massive sequencing and amplification of the 16S rRNA gene from nasopharyngeal samples between the patients allocated to CPAP group and the control group
Measured: 4 months
Change from baseline in microbiota population color maps from stool samples
To compare the change in microbiota population color maps, after massive sequencing and amplification of the 16S rRNA gene from stool samples between the patients allocated to CPAP group and the control group
Measured: 4 months
Change from baseline in microbiota color maps from nasopharyngeal samples
To compare the change in microbiota population color maps, after massive sequencing and amplification of the 16S rRNA gene from nasopharyngeal samples between the patients allocated to CPAP group and the control group
Measured: 4 months
Secondary outcomes (43)
Augmentation index (%)
To compare Augmentation index (%) in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Pulse wave velocity (m/sec)
To compare pulse wave velocity (m/sec) in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Aortic systolic blood pressure central (mmHg)
To compare systolic blood pressure central (mmHg) in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Diastolic blood pressure central (mmHg)
To compare diastolic blood pressure central (mmHg) in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Subendocardial viability ratio (%)
To compare subendocardial viability ratio (%) in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Central augmentation pressure (mmHg)
To compare central augmentation pressure (mmHg) in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Time to reflection (ms)
To compare time to reflection (ms) in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Peripheral systolic blood pressure (mmHg)
To compare peripheral systolic blood pressure (mmHg) in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Peripheral diastolic blood pressure (mmHg)
To compare diastolic blood pressure central (mmHg) in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Nocturnal blood pressure dipping
To compare number of patients with nocturnal blood pressure dipping in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Nocturnal hypertension.
To compare number of patients with nocturnal hypertension in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Patients with undiagnosed hypertension
To compare number of patients with undiagnosed hypertension in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
C-reactive protein (CRP)
To compare CRP in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Homocysteine
To compare homocysteine (μmol/L) in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Endothelin
To compare endothelin levels in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Angiotensin
To compare angiotensin levels in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group
Measured: Baseline and 4 months
8 isoprostane levels in OSA and in non-OSA patients
To compare 8 isoprostane levels in OSA and in non-OSA patients.
Measured: Baseline
Lipid profile
To compare lipid profile with same units of measure (all in mg/dL) in OSA and in non-OSA patients and to compare baseline (OSA vs. non-OSA), and the change from baseline in lipid profile between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Circulating inflammatory proteomic profile in OSA
To compare the circulating inflammatory proteomic profile using proximity expression assay technology (Olink®, Sweden, which comprised 96 proteins. All data are expressed as normalized protein expression values) in OSA and in non-OSA patients and to compare the change from baseline the circulating inflammatory proteomic profile between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Systemic inflammation.
To compare systemic inflammation (IL1bbeta IL-6, IL-8, HIF1 alpha, TNF-1alpha) with same units of measure (all in pg/mL) in OSA and in non-OSA patients and to compare the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Intake-regulating hormones.
To compare intake-regulating hormones with same units of measure (all in µg/mL) in OSA and in non-OSA patients and to compare the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Change from baseline in number of patients with desaturation index >3%
To compare the change from baseline in number of patients with desaturation index ≥ 5 h-1, ≥ 15 h-1, and ≥ 30 h-1 between the patients allocated to CPAP group and the control group
Measured: 4 months
Microbiota population abundance from stool and nasopharyngeal samples in OSA and in non-OSA patients
To compare microbiota population abundance from stool and nasopharyngeal samples in OSA and in non-OSA patients
Measured: Baseline
Microbiota population diversity from stool and nasopharyngeal samples in OSA and in non-OSA patients
To compare microbiota population diversity from stool and nasopharyngeal samples in OSA and in non-OSA patients
Measured: Baseline
Microbiota population color maps from stool and nasopharyngeal samples in OSA and in non-OSA patients
To compare microbiota population color maps from stool and nasopharyngeal samples in OSA and in non-OSA patients
Measured: Baseline
Relationships of microbiota population diversity from stool and nasopharyngeal samples in OSA to blood pressure profile.
To relate microbiota population diversity from stool and nasopharyngeal samples to blood pressure profile.
Measured: Baseline and 4 months
Relationships of microbiota population abundance from stool and nasopharyngeal samples in OSA to blood pressure profile
To relate microbiota population diversity from stool and nasopharyngeal samples to blood pressure profile.
Measured: Baseline and 4 months
Relationships of microbiota population color maps from stool and nasopharyngeal samples in OSA to blood pressure profile
To relate microbiota population color maps from stool and nasopharyngeal samples to blood pressure profile.
Measured: Baseline and 4 months
Relationships of microbiota population diversity from stool and nasopharyngeal samples in OSA to augmentation index.
To relate microbiota population diversity from stool and nasopharyngeal samples to augmentation index.
Measured: Baseline and 4 months
Relationships of microbiota population abundance from stool and nasopharyngeal samples in OSA to augmentation index.
To relate microbiota population diversity from stool and nasopharyngeal samples to augmentation index.
Measured: Baseline and 4 months
Relationships of microbiota population color maps from stool and nasopharyngeal samples in OSA to augmentation index.
To relate microbiota population color maps from stool and nasopharyngeal samples to augmentation index.
Measured: Baseline and 4 months
Relationships of microbiota population diversity from stool and nasopharyngeal samples in OSA to pulse wave velocity.
To relate microbiota population diversity from stool and nasopharyngeal samples to pulse wave velocity.
Measured: Baseline and 4 months
Relationships of microbiota population abundance from stool and nasopharyngeal samples in OSA to pulse wave velocity.
To relate microbiota population diversity from stool and nasopharyngeal samples to pulse wave velocity.
Measured: Baseline and 4 months
Relationships of microbiota population color maps from stool and nasopharyngeal samples in OSA to pulse wave velocity.
To relate microbiota population color maps from stool and nasopharyngeal samples to pulse wave velocity.
Measured: Baseline and 4 months
Vitamin D
To compare Vitamin D levels in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group
Measured: Baseline and 4 months
Glucose metabolism indices
To compare glucose metabolism indices [(hemoglobin A1c, fasting insulin level, homeostasis model assessment of insulin resistance (HOMA-IR), Quantitative Insulin Sensitivity Check Index (QUICKY) and triglyceride-glucose index, triglyceride glucose-waist circumference, triglyceride glucose-Body Mass index] in OSA and in non-OSA patients and to compare the change from baseline between the patients allocated to CPAP group and the control group
Measured: Baseline and 4 months
Hematological prognostic biomarkers
To compare neutrophil to lymphocyte, hemoglobin-to-red cell distribution width in OSA and in non-OSA patients and to compare the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Obesity indices
To compare body mass index, body fat composition in OSA and in non-OSA patients and to compare the change from baseline between the patients allocated to CPAP group and the control group
Measured: Baseline and 4 months
Ambulatory blood pressure monitoring (mmHg)
To compare 24-hour (systolic blood pressure, diastolic blood pressure, mean blood pressure, daytime systolic blood pressure, daytime diastolic blood pressure, daytime mean blood pressure, nighttime systolic blood pressure, nighttime diastolic blood pressure, nighttime mean blood pressure) (all in mmHg) in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group
Measured: Baseline and 4 months
Nocturnal oxygenation indices
To compare (oxygen desaturación index, time spent with oxygen saturation below 90%) in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Change from baseline in number of patients with Obesity
To compare the change from baseline in number of patients with obesity and abdominal obesity between the patients allocated to CPAP group and the control groups
Measured: 4 months
Daytime hypersomnolence
To compare Epworth sleepiness scale (ESS) and number of patients with ESS >10 in OSA and in non-OSA patients, and the change from baseline between the patients allocated to CPAP group and the control group.
Measured: Baseline and 4 months
Change from baseline in number of patients with metabolic syndrome or prediabetes
To compare the change from baseline in number of patients with metabolic syndrome and prediabetes profile between the patients allocated to CPAP group and the control group
Measured: 4 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jun 2020
- Study start20 Jul 2020
- Primary completion1 Oct 2026
- Study completion2 Oct 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Sleep Apnea, ObstructiveStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 130 participants (actual)
Sponsor and investigators
- Lead sponsor
- Alberto Alonso Fernandez
- Sponsor type
- Other government
- Collaborators
- Instituto de Salud Carlos III
- Responsible party
- Sponsor-investigator, Alberto Alonso Fernandez, Fundació d'investigació Sanitària de les Illes Balears
- Investigators
- Alberto Alonso, Dr, Principal investigator, Fundació d'investigació Sanitària de les Illes Balears
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04444778
- Sponsor's protocol ID
- PI19/00875
- Status last verified
- Oct 2026
- First submitted
- 6 Jun 2020
- Last updated
- 7 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Intermitent Hypoxia and Its Pathophysiology Consequences in the Sleep Apnea-Hypopnea Syndrome. Basic, Clinical and Therapeutically Study.
- ClinicalTrials.gov ID
- NCT04444778
- Acronym / sponsor ID
- PI19/00875
- Conditions
- Sleep Apnea, Obstructive
- Keywords
- sleep apnea syndrome
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 130 participants (actual)
- Lead sponsor
- Alberto Alonso FernandezOther government
- Collaborators
- Instituto de Salud Carlos III
- Study start
- 20 Jul 2020 (actual)
- Primary completion
- 1 Oct 2026 (actual)
- Study completion
- 2 Oct 2026 (actual)
- First posted
- 24 Jun 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Clinical trial on the effect of continuous positive pressure (CPAP). Objectives: 1) To assess the total or partial recovery of oxidative and inflammatory damage after recovering IH. 2) To check whether the results obtained in vitro on the recovery of the damage according to the form of manifestation of IH are validated in SAHS patients. 3) To determine if CPAP reduces nighttime blood pressure and arterial stiffness depending on whether or not patients have a non-dipping pattern of blood pressure and depending on the degree of correction of IH. 4) To clarify whether residual nocturnal hypoxemia influences the recovery of oxidative and inflammatory damage in patients. 5) To determine nasal and intestinal microbioma and the effect of CPAP treatment
Detailed description
Design: Randomized, parallel group, non-blinded, controlled clinical trial compared with conventional treatment.
- Protocol and intervention Patients with an AHI>30 h-1 will be assigned, using a 1:1 randomization table, to lifestyle recommendations treatment or to lifestyle recommendations plus nasal CPAP, for a period of 4 months. CPAP pressure will be titled with automatic using an AutoSet II device, ResMed.
- Sample size For the estimation of the sample size, previous data from our group were used. In this case, in order to compare the effect of CPAP in a subgroup of patients with well-controlled OSA and in another with residual hypoxemia; it would be necessary to randomize a total of 100 patients with OSA.
- Ethical considerations
- Indication of CPAP treatment for the prevention of cardiovascular morbidity and mortality in OSA patients without daytime sleepiness is not yet accepted.
- Those patients with a urgent study indication for the diagnosis and treatment of respiratory sleep disorders (professional drivers, respiratory failure or risk professions) will be excluded from the project. In the other cases, the delay in healthcare for the performance of Polysomnography and CPAP titration exceeds the duration of the study, therefore that patients assigned to the control arm (conventional treatment) will not be exposed to a higher risk than the general population.
- Methods
- Polysomnography. It will be used as a screening test previous the randomization of the included patients. The exploration and its interpretation will be carried out following the recommendations of the American Academy of Sleep Medicine. Based on the results of this test, only those patients with an AHI will continue in the study when AHI >30 h-1. In these patients the determinations listed below will be carried out immediately before randomization (visit 1), at 4 weeks (visit 2), 16 weeks (visit 4) of allocation to the corresponding treatment group
- Clinical data: The medication used and other associated diseases already diagnosed will be recorded.
- Vital signs: recording of blood pressure, by means of a conventional triple taking, and heart rate.
- Anthropometric characteristics: age and weight in basal conditions, the perimeter of the neck and waist / hip index will be measured. The lean mass index will be determined using a Bodystat 1500 impedance system (Bodystat Ltd, United Kingdom).
- Questionnaires: Epworth Sleepiness Scale, generic health-related quality of life (SF-12 and EuroQoL) and daily physical activity (International Physical Activity Questionnaire or iPAQ).
- Laboratory findings: blood count, coagulation, creatinine, serum sodium and potassium; glycated hemoglobin (HbA1c) and blood glucose and insulin levels in fasting, from these values will determine the resistance and sensitivity to insulin using the HOMA and QUICKI indices; total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides; and troponin I, homocysteine, NT-pro BNP and highly sensitive C-reactive protein.
- Blood venous samples. 20 mL of venous blood will be collected, storing the plasma obtained at -80 ºC for subsequent determination of inflammatory markers (IL-1ß, IL-6, IL-8, HIF 1- a and TNF-a), oxidative stress (8-isoprostane), endothelial damage (endothelin, angiotensin), and appetite-regulating hormones (leptin and adiponectin).
- Plasma proteins from peripheral blood samples will be analyzed using a high-throughput multiplex immunoassay technology based on the Proximity Extension Assays (PEA) (OLINK Bioscience, Uppsala, Sweden). Olink (OLINK Bioscience, Uppsala, Sweden).
- Night pulse oximetry. To assess the existence of residual nocturnal hypoxemia.
- Arterial stiffness. According to the recommendations by Sphygmo-Corsystem (version 7, AtCor Medical, Sydney, Australia).
- Study of the gut and pharyngeal microbiota by massive sequencing (next generation sequencing) after PCR amplification of the 16S rRNA gene, paired-end sequencing with Illumina technology (16S Amplicon and XT Nextera Metagenomic) and subsequent metataxonomic analysis of the microbial populations.
- Ambulatory blood pressure monitoring (ABPM) with Mortara's Ambulo 2400 ambulatory blood pressure device.
- In the patients assigned to the CPAP treatment arm, a count of the hours of use of the CPAP will be carried out at each visit by directly reading the automatic counter of each equipment.
Statistic analysis The data will be expressed as mean ± standard deviation, median (interquartile range) or percentage, depending on their type and distribution. For comparison between groups Student's t-test, the U-Mann-Whitney or the chi-square test will be used, as appropriate. The relations between variables will be analyzed using Pearson's correlation and multiple linear regression analysis. The effect of treatment will be evaluated using analysis of covariance (ANCOVA) to compare the change in log-transformed 8-isoprostane for the CPAP versus the usual care group, with the treatment group as a factor, and baseline 8-isoprostane, body mass index, smoking, and age as covariates. Intention-to-treat analysis included all randomized patients, whereas the per-protocol analysis set was defined as all patients in the full analysis who completed the study and, in the group treated with CPAP, achieved adherence greater than 4 hours per night. A multiple logistic regression model will be applied to determine the related variables with a response to treatment. Values of p <0.05 will be considered statistically significant. The statistical study will be performed with the SPSS program version 15.0.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Continuous positive airway pressure | Active comparator | Device: CPAPDiet and general life style recommendations plus continuous positive airway pressure (CPAP). |
| Conservative treatment | No intervention | –Diet and general life style recommendations. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Cases: patients with AHI > 30
- Controls: subjects with AHI < 5 and Epworth >10
Key exclusion criteria (13 listed)
- Epworth>18
- BMI<40Kg/M2
- Arterial Hypertension
- Mellitus Diabetes
- Cerebrovascular disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| CPAPContinuous positive airway pressure | Device | Continuous positive airway pressure |
Primary outcome
Change from baseline in 8 isoprostane levels
Time frame: 4 months
To compare the change in 8 isoprostane levels between the patients allocated to CPAP group and the control group
Change from baseline in microbiota population diversity from stool samples
Time frame: 4 months
To compare the change in in microbiota population diversity, after massive sequencing and amplification of the 16S rRNA gene from stool samples between the patients allocated to CPAP group and the control group
Change from baseline in microbiota population diversity from nasopharyngeal samples
Time frame: 4 months
To compare the change in microbiota population diversity, after massive sequencing and amplification of the 16S rRNA gene from nasopharyngeal samples between the patients allocated to CPAP group and the control group
Change from baseline in microbiota population abundance from stool samples
Time frame: 4 months
To compare the change in microbiota population abundance, after massive sequencing and amplification of the 16S rRNA gene from stool samples between the patients allocated to CPAP group and the control group
Change from baseline in microbiota population abundance from nasopharyngeal samples
Time frame: 4 months
To compare the change in microbiota population abundance, after massive sequencing and amplification of the 16S rRNA gene from nasopharyngeal samples between the patients allocated to CPAP group and the control group
Change from baseline in microbiota population color maps from stool samples
Time frame: 4 months
To compare the change in microbiota population color maps, after massive sequencing and amplification of the 16S rRNA gene from stool samples between the patients allocated to CPAP group and the control group
Change from baseline in microbiota color maps from nasopharyngeal samples
Time frame: 4 months
To compare the change in microbiota population color maps, after massive sequencing and amplification of the 16S rRNA gene from nasopharyngeal samples between the patients allocated to CPAP group and the control group
43 secondary outcomes
Augmentation index (%)
Time frame: Baseline and 4 months
Pulse wave velocity (m/sec)
Time frame: Baseline and 4 months
Aortic systolic blood pressure central (mmHg)
Time frame: Baseline and 4 months
Diastolic blood pressure central (mmHg)
Time frame: Baseline and 4 months
Subendocardial viability ratio (%)
Time frame: Baseline and 4 months
Central augmentation pressure (mmHg)
Time frame: Baseline and 4 months
Time to reflection (ms)
Time frame: Baseline and 4 months
Peripheral systolic blood pressure (mmHg)
Time frame: Baseline and 4 months
Peripheral diastolic blood pressure (mmHg)
Time frame: Baseline and 4 months
Nocturnal blood pressure dipping
Time frame: Baseline and 4 months
Nocturnal hypertension.
Time frame: Baseline and 4 months
Patients with undiagnosed hypertension
Time frame: Baseline and 4 months
C-reactive protein (CRP)
Time frame: Baseline and 4 months
Homocysteine
Time frame: Baseline and 4 months
Endothelin
Time frame: Baseline and 4 months
Angiotensin
Time frame: Baseline and 4 months
8 isoprostane levels in OSA and in non-OSA patients
Time frame: Baseline
Lipid profile
Time frame: Baseline and 4 months
Circulating inflammatory proteomic profile in OSA
Time frame: Baseline and 4 months
Systemic inflammation.
Time frame: Baseline and 4 months
Intake-regulating hormones.
Time frame: Baseline and 4 months
Change from baseline in number of patients with desaturation index >3%
Time frame: 4 months
Microbiota population abundance from stool and nasopharyngeal samples in OSA and in non-OSA patients
Time frame: Baseline
Microbiota population diversity from stool and nasopharyngeal samples in OSA and in non-OSA patients
Time frame: Baseline
Microbiota population color maps from stool and nasopharyngeal samples in OSA and in non-OSA patients
Time frame: Baseline
Relationships of microbiota population diversity from stool and nasopharyngeal samples in OSA to blood pressure profile.
Time frame: Baseline and 4 months
Relationships of microbiota population abundance from stool and nasopharyngeal samples in OSA to blood pressure profile
Time frame: Baseline and 4 months
Relationships of microbiota population color maps from stool and nasopharyngeal samples in OSA to blood pressure profile
Time frame: Baseline and 4 months
Relationships of microbiota population diversity from stool and nasopharyngeal samples in OSA to augmentation index.
Time frame: Baseline and 4 months
Relationships of microbiota population abundance from stool and nasopharyngeal samples in OSA to augmentation index.
Time frame: Baseline and 4 months
Relationships of microbiota population color maps from stool and nasopharyngeal samples in OSA to augmentation index.
Time frame: Baseline and 4 months
Relationships of microbiota population diversity from stool and nasopharyngeal samples in OSA to pulse wave velocity.
Time frame: Baseline and 4 months
Relationships of microbiota population abundance from stool and nasopharyngeal samples in OSA to pulse wave velocity.
Time frame: Baseline and 4 months
Relationships of microbiota population color maps from stool and nasopharyngeal samples in OSA to pulse wave velocity.
Time frame: Baseline and 4 months
Vitamin D
Time frame: Baseline and 4 months
Glucose metabolism indices
Time frame: Baseline and 4 months
Hematological prognostic biomarkers
Time frame: Baseline and 4 months
Obesity indices
Time frame: Baseline and 4 months
Ambulatory blood pressure monitoring (mmHg)
Time frame: Baseline and 4 months
Nocturnal oxygenation indices
Time frame: Baseline and 4 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Oct 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Alberto Alonso, Dr principal investigator
Fundació d'investigació Sanitària de les Illes Balears
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing CPAP in people with Sleep Apnea, Obstructive, run by Alberto Alonso Fernandez at 2 sites in Spain.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 7 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from baseline in 8 isoprostane levels (time frame: 4 months). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Oct 2026; AzTrials last refreshed its copy on 26 Oct 2026.