Empagliflozin and CPAP in Adults With Heart Failure and Obstructive Sleep Apnea.

NCT07556094 | Completed

• 1 other identifier: APK.002.526.2022
• Study Type: interventional
• Target: 70
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this randomized clinical trial was to evaluate the effects of empagliflozin, a sodium-glucose cotransporter-2 inhibitor (SGLT2i) on sleep and cardiac outcomes in adults with heart failure (HF) and obstructive sleep apnea syndrome (OSA). The study also examined how subsequent initiation of continuous positive airway pressure (CPAP) therapy affected sleep and cardiac outcomes, and whether response to treatment differed according to baseline obstructive sleep apnea severity. The main questions it aims to answer were:

• Does empagliflozin affect sleep apnea severity and nocturnal oxygenation before CPAP initiation?
• Does prior empagliflozin treatment influence the response to subsequent CPAP therapy?
• Does empagliflozin affect oxidative stress markers, including total oxidative status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI)?
• Does CPAP therapy initiation affect cardiac outcomes in both groups?
• Does response to treatment differ according to baseline obstructive sleep apnea severity, including mild, moderate, and severe disease? Researchers compared participants receiving empagliflozin in addition to background HF therapy with those continuing background HF therapy without empagliflozin to evaluate the effects of empagliflozin. Participants:
• Were randomly assigned to receive empagliflozin plus background HF pharmacotherapy or background HF pharmacotherapy therapy without empagliflozin
• Underwent sleep studies, transthoracic echocardiography and clinical assessments at baseline, 3 months, and 6 months.
• Provided blood samples for measurement of cardiac biomarkers and oxidative stress markers.
• Completed standardized questionnaires assessing sleep quality and symptoms.
• Initiated CPAP therapy after 3 months and continued treatment until the end of the study.

Conditions

Obstructive Sleep Apnea (OSA); Sleep Apnea Syndrome, Obstructive; Heart Failure

Keywords

sleep; sleep apnea; apnea; obstructive sleep apnea; heart; heart failure

Outcome Measures

Primary Outcomes (1)

• Change in Apnea-Hypopnea Index (AHI).

  Change in AHI, measured as the number of apnea and hypopnea events per hour of sleep, assessed between baseline and follow-up visits at 3 and 6 months.

  Baseline, 3 months, and 6 months.

Secondary Outcomes (1)

• Change in N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations.

  Baseline, 3 months, and 6 months.

Other Outcomes (12)

• Change in nocturnal oxygenation - mean oxygen saturation (MOS).

  Baseline to 3 months and 6 months.

• Change in nocturnal oxygenation - lowest oxygen saturation (LOS).

  Baseline to 3 months and 6 months.

• Change in nocturnal oxygenation - time spent with oxygen saturation below 90% (T<90%).

  Baseline to 3 months and 6 months.

Study Arms (2)

Empagliflozin + Background Heart Failure Therapy

EXPERIMENTAL

Participants with HF and OSA initiated empagliflozin at baseline in addition to background heart failure therapy and continued treatment throughout the 6-month study period. During the first phase (0-3 months), the effects of empagliflozin were assessed. Continuous positive airway pressure therapy was initiated after 3 months and continued until the end of the study. This design allowed evaluation of the isolated effect of empagliflozin before CPAP initiation and assessment of its influence on response to subsequent CPAP therapy.

Drug: Empagliflozin; Device: Continuous Positive Airway Pressure (CPAP)

Background Heart Failure Therapy Without Empagliflozin

ACTIVE COMPARATOR

Participants continued background heart failure therapy without empagliflozin. Continuous positive airway pressure (CPAP) therapy was initiated after 3 months and continued until the end of the study. This design allowed evaluation of the isolated effect of empagliflozin before CPAP initiation and assessment of its influence on response to subsequent CPAP therapy.

Device: Continuous Positive Airway Pressure (CPAP)

Interventions

Empagliflozin DRUG

Empagliflozin was initiated at baseline at a dose of 10 mg once daily, administered orally, in addition to background heart failure therapy, and continued throughout the 6-month study period.

Empagliflozin + Background Heart Failure Therapy

Continuous Positive Airway Pressure (CPAP) DEVICE

Continuous positive airway pressure therapy was initiated after 3 months in all participants using standard clinical practice. CPAP was applied nightly during sleep, with pressure settings individually titrated. The mean therapeutic pressure was approximately 15.5 ± 2.5 cm H₂O. Treatment was continued until the end of the study.

Background Heart Failure Therapy Without Empagliflozin; Empagliflozin + Background Heart Failure Therapy

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥18 years
• Diagnosed heart failure (HF) on stable guideline-directed medical therapy
• Obstructive sleep apnea (OSA) confirmed by sleep study (mild, moderate, or severe)
• No prior treatment with empagliflozin or other sodium-glucose cotransporter-2 inhibitors
• No prior treatment with continuous positive airway pressure therapy
• Body mass index (BMI) \<40 kg/m²
• Clinical eligibility for CPAP therapy according to current recommendations
• Ability to provide written informed consent

You may not qualify if:

• Age \<18 years
• Body mass index (BMI) ≥40 kg/m²
• Active malignancy
• Severe renal impairment (estimated glomerular filtration rate \<25 mL/min/1.73 m²)
• Advanced hepatic insufficiency
• Symptomatic hypotension
• Clinically significant volume depletion or dehydration
• Known hypersensitivity to empagliflozin or any component of the study medication
• Any condition that, in the opinion of the investigator, could interfere with study participation or interpretation of results

Sponsors & Collaborators

• Medical University of Bialystok: lead

Study Sites (1)

University Clinical Hospital in Białystok

Bialystok, Podlaskie Voivodeship, 15-276, Poland

Location

MeSH Terms

Conditions

Sleep Apnea, Obstructive; Heart Failure; Sleep Apnea Syndromes; Apnea

Interventions

empagliflozin; Continuous Positive Airway Pressure

Condition Hierarchy (Ancestors)

Respiration Disorders; Respiratory Tract Diseases; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases; Heart Diseases; Cardiovascular Diseases; Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Positive-Pressure Respiration; Respiration, Artificial; Airway Management; Therapeutics; Respiratory Therapy

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: This was an open-label study without masking. Objective outcome measures, including sleep study parameters, echocardiographic assessments, and biochemical markers, were used to minimize potential bias.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Medical Doctor

Model Details: Parallel-group randomized controlled trial with a sequential two-phase design. Participants were randomized 1:1 to receive empagliflozin in addition to background heart failure therapy or to continue background therapy without empagliflozin. During the first phase (0-3 months), the effect of empagliflozin was assessed. During the second phase (3-6 months), continuous positive airway pressure (CPAP) therapy was initiated in all participants, while empagliflozin was continued in the intervention group, allowing evaluation of CPAP effects and the influence of prior empagliflozin exposure on treatment response. The sequential design allowed separation of early pharmacological effects from later CPAP-driven improvements and enabled assessment of whether prior SGLT2 inhibition modifies subsequent response to CPAP therapy.

Study Record Dates

• First Submitted: April 15, 2026
• First Posted: April 29, 2026
• Study Start: June 5, 2023
• Primary Completion: May 9, 2025
• Study Completion: May 9, 2025
• Last Updated: April 29, 2026

Record last verified: 2026-04

Locations

PL (1)