Comparison of Awakening Versus Bedtime Dosing of Aspirin in Pre-Hypertension or Mild Essential Hypertension - Full Text View

Purpose

Aspirin (ASA) has been shown to provide marked benefits in the prevention of cardiovascular events, although the potential direct effects of ASA on cardiovascular function remain uncertain. Previous studies have demonstrated that ASA is a potent antioxidative agent that markedly reduces vascular production of superoxide in normotensive and hypertensive rats. In addition, ASA was found to prevent angiotensin II-induced hypertension and cardiovascular hypertrophy, mainly through its antioxidative properties in preventing the generation of superoxide, although ASA apparently did not appear to reduce hypertensive levels of blood pressure (BP). Moreover, recent results have demonstrated that ASA induces nitric oxide (NO) release from vascular endothelium. No attention has been paid, so far, to potential administration time-dependent effects in these studies.

Previous laboratory animal and clinical trial research convincingly demonstrates administration time-dependent (with reference to circadian rhythms) effects of ASA. Thus, the effects of ASA upon lipoperoxides, β-adrenergic receptors, and BP in clinically healthy subjects depend on the circadian timing of ASA administration. Most important, the administration time-dependent influence of ASA on BP was previously demonstrated in a randomized trial on healthy women and in other independent, double-blind, randomized, placebo-controlled clinical trials. The first was conducted on clinically healthy subjects, a second one on normotensive and hypertensive subjects, a third one on pregnant women at high risk for preeclampsia and a fourth one in previously untreated patients with mild hypertension. The findings of these BP studies are consistent; the BP-lowering effect of low-dose ASA is achieved when administered at bedtime but not upon awakening.

In keeping with the chronopharmacological effects of ASA and the previous findings suggesting that ASA at low dose may have a potential beneficial effect on BP, this prospective, randomized, double-blind, crossover study will investigate the potential influence of ASA on BP in subjects with either high-normal BP or diagnosis of mild (grade 1) hypertension. The subjects will receive low-dose ASA or placebo at different times of the day according to their rest-activity cycle, and will be evaluated by 48-hour ambulatory BP monitoring before and after 6 weeks of pharmacologic intervention.

Condition	Intervention	Phase
High-Normal Blood Pressure Mild Essential Hypertension	Drug: Aspirin 100 mg Device: Ambulatory blood pressure monitoring Procedure: Chronotherapy, timing of medication Drug: Placebo	Phase 4

Study Type:	Interventional
Study Design:	Allocation: Randomized Endpoint Classification: Safety/Efficacy Study Intervention Model: Crossover Assignment Masking: Double Blind (Subject, Caregiver, Investigator) Primary Purpose: Treatment
Official Title:	A Prospective, Randomized, Multi-Center, Double-Blind Crossover Study to Compare Awakening Versus Bedtime Administration of 100 mg Aspirin or Placebo in Subjects With High-Normal Blood Pressure or Mild Essential Hypertension

Resource links provided by NLM:

MedlinePlus related topics: High Blood Pressure

Drug Information available for: Aspirin

U.S. FDA Resources

Further study details as provided by University of Vigo:

Primary Outcome Measures:

To demonstrate the efficacy of bedtime administration of aspirin by testing the hypothesis of superior 24 hour systolic BP (SBP) lowering compared with either aspirin administered on awakening or with placebo at any circadian time [ Time Frame: 14 weeks ] [ Designated as safety issue: No ]

Secondary Outcome Measures:

To demonstrate that aspirin at bedtime is more effective than aspirin upon awakening and placebo in terms of 24 hour diastolic BP (DBP) lowering [ Time Frame: 14 weeks ] [ Designated as safety issue: No ]
To demonstrate that aspirin at bedtime is more effective in non-dipper subjects as compared to dippers in terms of nocturnal SBP/DBP lowering, and that this effect is superior to any potential effect on BP of aspirin upon awakening or placebo [ Time Frame: 14 weeks ] [ Designated as safety issue: No ]
To demonstrate that aspirin at bedtime offers a similar safety profile to aspirin upon awakening and to placebo [ Time Frame: 14 weeks ] [ Designated as safety issue: Yes ]
To demonstrate that compliance with aspirin at bedtime is similar to compliance with either aspirin upon awakening or placebo [ Time Frame: 14 weeks ] [ Designated as safety issue: No ]

Enrollment:	23
Study Start Date:	January 2007
Study Completion Date:	December 2008
Primary Completion Date:	December 2008 (Final data collection date for primary outcome measure)

Arms	Assigned Interventions
Active Comparator: 1 Aspirin 100 mg on awakening	Drug: Aspirin 100 mg dose of 100 mg administered on awakening or at bedtime Device: Ambulatory blood pressure monitoring Blood pressure measured at 20-min intervals from 07:00 to 23:00 hours and at 30-min intervals at night for 48 consecutive hours Procedure: Chronotherapy, timing of medication Dosing on awakening versus bedtime
Active Comparator: 2 Aspirin 100 mg at bedtime	Drug: Aspirin 100 mg dose of 100 mg administered on awakening or at bedtime Device: Ambulatory blood pressure monitoring Blood pressure measured at 20-min intervals from 07:00 to 23:00 hours and at 30-min intervals at night for 48 consecutive hours Procedure: Chronotherapy, timing of medication Dosing on awakening versus bedtime
Placebo Comparator: 3 Placebo on awakening	Device: Ambulatory blood pressure monitoring Blood pressure measured at 20-min intervals from 07:00 to 23:00 hours and at 30-min intervals at night for 48 consecutive hours Procedure: Chronotherapy, timing of medication Dosing on awakening versus bedtime Drug: Placebo Use of placebo on awakening versus bedtime
Placebo Comparator: 4 Placebo at bedtime	Device: Ambulatory blood pressure monitoring Blood pressure measured at 20-min intervals from 07:00 to 23:00 hours and at 30-min intervals at night for 48 consecutive hours Procedure: Chronotherapy, timing of medication Dosing on awakening versus bedtime Drug: Placebo Use of placebo on awakening versus bedtime

Detailed Description:

This is a multi-center, prospective, randomized, four-arm, crossover study with double-blind design.

At Visit 1 (week -1) patients will be assessed for eligibility for study participation. Subjects will be advised that study entry cannot be fully determined until the completion of the screening period when all exclusion/inclusion criteria are entirely assessed. Subjects will perform Visit 2 as soon as their laboratory results of Visit 1 are available. At baseline (Visit 2/Day 1), a total of 300 subjects whose eligibility is confirmed will be randomized in a 1:1:1 ratio to one of the treatment groups (aspirin upon awakening, aspirin at bedtime, or placebo--half on awakening, half at bedtime). Subjects will start a first double-blind treatment phase with a total duration of 6 weeks. During this period the subjects will be receiving either aspirin 100 mg or placebo at two different circadian times (either after awakening from nighttime sleep or before bedtime) until the end of this study phase (Visit 3). After this first treatment phase, all subjects will undergo a 2-week wash-out phase with placebo. At Visit 4 (week 8), all subjects will be crossed-over in terms of the circadian time, but keeping their original treatment (either aspirin or placebo), and followed up for a second treatment phase of 6 weeks.

The study duration including all the phases will be 15 weeks.

Safety and efficacy will be assessed at the end of every treatment phase, i.e., at Visits 3 and 5. Safety will also be assessed by phone calls 2 weeks after the initiation of each active treatment phase (weeks 2 and 10). Subjects may be requested to attend the clinic for further evaluation on those weeks if they present any adverse effect.

Eligibility

Ages Eligible for Study:	18 Years and older
Genders Eligible for Study:	Both
Accepts Healthy Volunteers:	Yes

Criteria

Inclusion Criteria:

High-normal blood pressure
Mild essential hypertension

Exclusion Criteria:

Moderate-severe hypertension.
Secondary hypertension.
Grade III/IV hypertensive retinopathy.
Type 1 diabetes.
Body mass index ≥ 35 kg/m2
Cerebrovascular or cardiovascular event during the last 12 months prior to inclusion.
Pregnant or lactating females.
History of malignancy within the past five years.
Shift workers.
Obstructive sleep apnea.
Use of disallowed concomitant medication.
Intolerant to ambulatory BP monitoring (ABPM).

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT00449618

Locations

Spain
Centro de Salud de A Guarda
La Guardia, Pontevedra, Spain
Centro de Salud de Sardoma
Vigo, Pontevedra, Spain, 36214
Centro de Salud de A Doblada
Vigo, Pontevedra, Spain
C.S. Lérez
Pontevedra, Spain
Hospital Clínico Universitario de Santiago
Santiago de Compostela, Spain, 15701

Sponsors and Collaborators

University of Vigo

Hospital Clinico Universitario de Santiago

Bayer

Investigators

Principal Investigator:

Ramon C Hermida, Ph.D.

University of Vigo

More Information

No publications provided

Responsible Party:	Ramon C. Hermida, University of Vigo
ClinicalTrials.gov Identifier:	NCT00449618 History of Changes
Other Study ID Numbers:	ASA100-2004/2, 2004-004987-65, 2006-004652-21
Study First Received:	March 19, 2007
Last Updated:	December 31, 2008
Health Authority:	Spain: Ministry of Health

Keywords provided by University of Vigo:

Aspirin
Ambulatory blood pressure monitoring
Chronotherapy
Circadian

Additional relevant MeSH terms:

Hypertension
Vascular Diseases
Cardiovascular Diseases
Aspirin
Anti-Inflammatory Agents, Non-Steroidal
Analgesics, Non-Narcotic
Analgesics
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Pharmacologic Actions
Anti-Inflammatory Agents

Therapeutic Uses
Antirheumatic Agents
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Cardiovascular Agents
Hematologic Agents
Platelet Aggregation Inhibitors
Cyclooxygenase Inhibitors
Enzyme Inhibitors
Antipyretics
Central Nervous System Agents

ClinicalTrials.gov processed this record on May 23, 2013