Clinical trial NCT04021550: Improving 24-hour Blood Pressure in Obstructive Sleep Apnea
Official title: Combined Treatment of Angiotensin Receptor Blocker and Antioxidant Supplementation as a Novel Adjunctive Therapy for 24-hour Blood Pressure Improvement in Obstructive Sleep Apnea
Study type: INTERVENTIONAL
Overall status: WITHDRAWN
Phase: EARLY_PHASE1
Conditions: Obstructive Sleep Apnea
Keywords: Telmisartan
Alpha-Lipoic Acid
Continuous Positive Airway Pressure
24-hour blood pressure
Lead sponsor: University of British Columbia
Sponsor class: OTHER
Collaborators: name: Heart and Stroke Foundation of Canada
name: Michael Smith Foundation for Health Research
First posted: 2019-07-16
Enrollment: 0
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: This study examines the combined effects of an angiotensin receptor blocker (ARB), antioxidant supplementation, and continuous positive airway pressure (CPAP) therapy on the lowering of 24-hour blood pressure in persons with moderate to severe Obstructive Sleep Apnea (OSA). All participants will undergo CPAP therapy as prescribed by their doctor; however, half of the participants will receive the combined ARB and antioxidant treatment while the other half of the participants will receive a placebo.

Detailed description: OSA is a sleep disorder characterized by repetitive collapses (apneas) or partial collapses (hypopneas) of the upper airway. These airway obstructions result in intermittent reductions in arterial oxygen saturation (hypoxia), which causes a reflexive increase in sympathetic activation and systemic vasoconstriction. Resumption of breathing results in transient surges in blood pressure (BP) that can reach as high as 240/130 mm/Hg.

OSA effects up to 24% of the adult population and evidence suggests a causal relationship between OSA and cardiovascular disease (CVD) development. While the exact mechanisms are unknown, data from animal and human models suggest that exposure to chronic intermittent hypoxia (IH) plays a significant role in the pathogenesis of cardiovascular comorbidity. Persons with OSA exhibit increased daytime sympathetic activity, markers of oxidative stress, and vasoactive hormones, particularly angiotensin II, that contribute to systemic vasoconstriction. These factors contribute to early endothelial dysfunction and contribute to sustained elevations in BP.

While CPAP is the gold standard OSA treatment, adherence rates are low and evidence suggests that treatment does not reduce the rates of CVD in large population-based studies.

Telmisartan is a receptor blocker for angiotensin II and not only has BP lowering effects, but also has unique anti-inflammatory properties and beneficial influences on endothelial function. The addition of an antioxidant supplement may increase the reactive oxygen species scavenging capacity and, in combination with ARB treatment, may provide more robust effects on BP in persons with OSA.

Eligibility criteria: Inclusion Criteria:

* Apnea/Hypopnea Index (AHI) greater than/equal to 15 events per hour of sleep
* No prior use of CPAP
* Body mass index less than 30kg/m2
* Does not take ARBs or angiotensin converting enzyme inhibitors for blood pressure control
* Females of childbearing potential on an effective or highly effective means of contraception

Exclusion Criteria:

* Prescribed and/or taking the following medications: diuretics (including potassium-sparing diuretics), Digoxin, lithium salts, and/or nonsteroidal anti-inflammatory drugs
* Over the counter supplements that affect the cardiovascular system, such as fish oils, vitamins, or other antioxidants
* History of heart failure
* History of myocardial infarction
* History of coronary artery disease
* History of stroke
* History of diabetes mellitus
* History of impaired renal function
* History of chronic obstructive pulmonary disease
* History of asthma
* History of central sleep apnea
* Smoked within the past year
* Hypotensive (Systolic blood pressure (SBP) \<90 mmHg and diastolic blood pressure (DBP) \<60 mmHg)
* Females who do not have a means of contraception, are pregnant, planning to become pregnant, and/or are breast-feeding

Primary outcomes:
measure: Change in 24-hour blood pressure
timeFrame: Change from baseline of 24-hour systolic, diastolic, and mean arterial blood pressure at 6 weeks
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
References:
citation: Frampton JE. Telmisartan: a review of its use in cardiovascular disease prevention. Drugs. 2011 Apr 16;71(6):651-77. doi: 10.2165/11206710-000000000-00000.
citation: Khayat RN, Varadharaj S, Porter K, Sow A, Jarjoura D, Gavrilin MA, Zweier JL. Angiotensin Receptor Expression and Vascular Endothelial Dysfunction in Obstructive Sleep Apnea. Am J Hypertens. 2018 Feb 9;31(3):355-361. doi: 10.1093/ajh/hpx174.
citation: Khayat R, Patt B, Hayes D Jr. Obstructive sleep apnea: the new cardiovascular disease. Part I: Obstructive sleep apnea and the pathogenesis of vascular disease. Heart Fail Rev. 2009 Sep;14(3):143-53. doi: 10.1007/s10741-008-9112-z. Epub 2008 Sep 20.
citation: Rotenberg BW, Murariu D, Pang KP. Trends in CPAP adherence over twenty years of data collection: a flattened curve. J Otolaryngol Head Neck Surg. 2016 Aug 19;45(1):43. doi: 10.1186/s40463-016-0156-0.
citation: Pepin JL, Tamisier R, Barone-Rochette G, Launois SH, Levy P, Baguet JP. Comparison of continuous positive airway pressure and valsartan in hypertensive patients with sleep apnea. Am J Respir Crit Care Med. 2010 Oct 1;182(7):954-60. doi: 10.1164/rccm.200912-1803OC. Epub 2010 Jun 3.