A Phase 4 interventional study of Hyperoxia/oxygen and Acetazolamide in Sleep Apnea and Elderly Adults, sponsored by VA Office of Research and Development. Recruiting at 1 site in United States. Open to participants aged 60 Years to 89 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-21.
Sponsored by VA Office of Research and Development · Phase 4, Interventional, and Other
Sleep-disordered breathing (SDB or sleep apnea) is very common among elderly Veterans and leads to increased morbidity and mortality in this population. The proposal aims to identity whether oxygen, finasteride and acetazolamide can be effective in reducing unstable breathing and eliminating sleep apnea in the elderly via different mechanisms. This proposal will enhance the investigators' understanding of the pathways that contribute to the development of sleep apnea in the elderly. The investigators expect that the results obtained from this study will positively impact the health of Veterans by identifying new treatment modalities for sleep apnea. A cumulative effect of the investigators' research will fulfill the long-term goal of improving the quality of life of elderly Veterans suffering from sleep apnea and its potential life-threatening complications.
Sleep apnea-hypopnea syndrome (SAHS) has a high prevalence and is associated with adverse cardiovascular consequences in elderly Veterans. Positive airway pressure therapy is deemed cumbersome and often associated with non-adherence to therapy. This proposal will investigate whether alternative therapies can be developed by modulating specific physiologic mechanisms of ventilatory control. Specifically, the investigators will study whether interventions with sustained hyperoxia (Aim 1), finasteride (Aim 2) and acetazolamide (Aim 3) will reduce breathing instability during sleep by reducing chemoresponsiveness and/or increasing cerebrovascular reactivity (CVR) in order to alleviate sleep disordered breathing in the elderly with sleep apnea. The proposed aims will also allow us to delineate key mechanisms of breathing instability in the elderly. The investigators envision that the results obtained from this project will ultimately allow us to develop novel alternative therapies for sleep apnea in the elderly. The investigators will also compare CVR in young vs older adults
1,084 studies on the registry are indexed under Sleep Apnea Syndromes; 171 are open to participants now.
This study's planned enrollment of 100 is above the median of 60 across 673 interventional studies indexed under Sleep Apnea Syndromes.
Browse Sleep Apnea Syndromes studies →VA Office of Research and Development is the lead sponsor of 1,771 studies on the registry; 392 are open to participants now.
Of its 213 completed or terminated interventional studies of FDA-regulated products, 185 (87%) have results posted.
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Patients on certain medications including:
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Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
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.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Determine the effect of sustained hyperoxia overnight vs room air overnight on ventilatory control during sleep, including the apneic threshold, carbon-dioxide reserve and chemosensitivity measured via pressure support ventilation (PSV) during (non-rapid eye movement sleep) NREM sleep.
Other: Hyperoxia/oxygen
Determine the effect of acetazolamide on cerebrovascular responsiveness to CO2 during wake and sleep. Participants will receive oral ACZ therapy for 7 days prior to the experimental night, on the night of the study and the subsequent night when polysomnography (PSG) will be performed.
Drug: Acetazolamide
Determine the effect of oral finasteride therapy vs placebo for 1 month on SDB and the AT and chemosensitivity during NREM sleep.
Drug: Finasteride
The ventilatory effects of brief hyperoxia will be assessed by analyzing control breaths on room air immediately preceding the hyperoxic exposure, and comparing with the primary end-point, nadir minute ventilation breath, immediately following the brief hyperoxic exposure
Participants with sleep apnea will ingest capsules containing either placebo or acetazolamide 500 mg twice a day for 5 days. On the final 2 consecutive nights while still on ACZ, the investigators will perform i) physiology tests and ii) in-lab follow-up PSG.
Elderly males with sleep apnea and adequate testosterone levels will ingest placebo vs finasteride, at 5 mg a day for 1 month (mo). After 1 mo, while still on the drug, on the final 2 consecutive nights, the investigators will perform i) physiology tests and ii) in-lab follow-up PSG. Blood tests will be performed to check sex hormone levels. A washout period of 1 month prior to cross-over to the alternate arm (placebo).
Apneic threshold- a measure of breathing instability
Measures of breathing instability including: Apneic threshold: this is the end-tidal Co2 at which a central apnea closes to a hypopnea is produced.
Time frame: 2 days to 30 days
Cerebrovascular responsiveness to carbon-dioxide
Cerebrovascular response to different levels of CO2: this is a measure of the response of the cerebral blood flow to changes in carbon dioxide levels and is used as a measure of ventilatory control of breathing
Time frame: 7 days
Ventilatory responsiveness
Hypocapnic ventilatory response; this is calculated as the change in minute ventilation for corresponding changes in PETCO2 (partial pressure of end-tidal carbon dioxide).
Time frame: 2 days to 30 days
Carbon -dioxide reserve
This is a derived measure. This is calculated as the difference between the apneic threshold PETCO2 (given above) and the control PETCO2 (partial pressure of end-tidal carbon dioxide).
Time frame: 2 days to 30 days
Apnea hypopnea index
Apnea hypopnea index- is a measure of severity of sleep apnea - this is calculated as the total number of apneas and hypopneas recorded during a sleep study divided by the total sleep time during the sleep study.
Time frame: 2 days to 30 days
Plan to share: No
Started Jul 2015 (actual). Primary completion is estimated for Jul 2027, 144 months after the start.
Of 25 phase 4 interventional studies under Sleep Apnea Syndromes, half reached primary completion within 34 months of starting (the median), counting those still running; a quarter within 18 and three quarters within 72. This study's planned 144 months is above that.
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Studies of the drugs tested here: Acetazolamide · Finasteride
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