Aspirin AM or PM: Effect on Circadian Rhythm of Platelet Reactivity

Cardiovascular Diseases Clinical Trial

Official title:

Effect of Aspirin Intake on Awakening Versus at Bedtime on Circadian Rhythm of Platelet Reactivity in Healthy Subjects

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01900639
• Other study ID #: NL.44378.058.13
• Secondary ID: 2013-001410-16P1
• Status: Completed
• Phase: Phase 4
• First received: July 12, 2013
• Last updated: February 19, 2014
• Start date: July 2013
• Est. completion date: January 2014

Study information

• Verified date: February 2014
• Source: Leiden University Medical Center
• Contact: n/a
• Is FDA regulated: No
• Health authority: Netherlands: Medical Ethics Review Committee (METC)
• Study type: Interventional

Clinical Trial Summary

Low-dose aspirin is a cornerstone in the secondary prevention of cardiovascular disease (CVD) and is usually taken on awakening, although evidence regarding optimal time of intake is lacking. Platelet reactivity follows a circadian rhythm, with a peak in the morning, contributing to the morning peak of cardiovascular disease. Due to its short half life, aspirin only inhibits platelets which are present at the time of intake. Thus, the timing of aspirin intake may influence its inhibitory effect on platelets and intake of aspirin at bedtime may attenuate the morning peak of platelet reactivity. The time-dependent effect of aspirin on circadian rhythm of platelet function has never been studied before. We hypothesize that aspirin intake at bedtime compared with intake on awakening results in a reduction of the morning peak in platelet reactivity.

Description:

Cardiovascular events are a leading cause of mortality and morbidity in western countries. In the European Union, 47% of total mortality is caused by cardiovascular disease2. Aspirin is a cornerstone in the secondary prevention of cardiovascular disease because of its inhibitory effects on platelet aggregation. It reduces the risk of recurrent cardiovascular events with about a quarter3. Although not supported by evidence, aspirin is usually taken in the morning, but it may be more beneficial to take aspirin at bedtime instead of on awakening. It has been convincingly shown that platelet activity follows a circadian rhythm, with a peak of platelet reactivity in the morning4-8. This might in part explain the increase in cardiovascular events in the early morning, with the highest incidence between 6 and 12 AM1.

Since platelet reactivity follows a circadian rhythm, the timing of aspirin intake may influence its inhibitory effect on platelets. Due to its short half-life, aspirin only inhibits platelets which are present at the time of intake. New platelets are released at a rate of 10%/day, predominantly during the night9. Because they are more reactive and not inhibited by aspirin taken in the preceding morning, these young platelets contribute to the morning peak of platelet reactivity10, 11. It has been argued that intake of aspirin at bedtime could better prevent the early morning increase in platelet reactivity than intake on awakening, assuming that intake on awakening would be too late to prevent this morning peak in platelet reactivity12. Additionally, a recent study showed significant recovery of platelet aggregation after 24 hours in patients using low-dose aspirin on a daily basis13. This supports the hypothesis that aspirin intake at bedtime could be beneficial in reducing the morning peak of platelet reactivity, thereby possibly also reducing the incidence of arterial thrombotic events in the morning. However, this has never been studied before.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 14
• Est. completion date: January 2014
• Est. primary completion date: January 2014
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Healthy subject

• Age >18yrs

• Capacity to give informed consent (IC)

Exclusion Criteria:

• Active chronic disease

• Use of any other medication

• History of: major bleeding events, known bleeding diathesis or disorder, cardiovascular disease, malignancy

• Known allergy to salicylates

• Platelet count < 150 * 109/L

• VerifyNow Aspirin Reaction Units <550 Aspirin Reaction Units (ARU)

• Smoking

• Shift work in preceding 2 months

• Extreme chronotypes, defined as regular (>2 days/week) bedtime <22:00h or >24:00h and/or awakening <6:00h or >9:00h

• Pregnancy

Study Design

Allocation: Randomized, Endpoint Classification: Pharmacokinetics/Dynamics Study, Intervention Model: Crossover Assignment, Masking: Open Label, Primary Purpose: Prevention

Related Conditions & MeSH terms

• Aspirin
• Cardiovascular Diseases
• Circadian Rhythm
• Platelet Activation

Intervention

Behavioral:
• change time of intake of aspirin

Locations

Country	Name	City	State
Netherlands	Leiden University Medical Center	Leiden

Sponsors (1)

Lead Sponsor	Collaborator
Leiden University Medical Center

Country where clinical trial is conducted

Netherlands, 

References & Publications (4)

Di Minno G, Silver MJ, Murphy S. Monitoring the entry of new platelets into the circulation after ingestion of aspirin. Blood. 1983 Jun;61(6):1081-5. — View Citation

Kriszbacher I, Ajtay Z, Koppán M, Bódis J. Can the time of taking aspirin influence the frequency of cardiovascular events? Am J Cardiol. 2005 Aug 15;96(4):608-10. — View Citation

Scheer FA, Michelson AD, Frelinger AL 3rd, Evoniuk H, Kelly EE, McCarthy M, Doamekpor LA, Barnard MR, Shea SA. The human endogenous circadian system causes greatest platelet activation during the biological morning independent of behaviors. PLoS One. 2011;6(9):e24549. doi: 10.1371/journal.pone.0024549. Epub 2011 Sep 8. — View Citation

Tofler GH, Brezinski D, Schafer AI, Czeisler CA, Rutherford JD, Willich SN, Gleason RE, Williams GH, Muller JE. Concurrent morning increase in platelet aggregability and the risk of myocardial infarction and sudden cardiac death. N Engl J Med. 1987 Jun 11;316(24):1514-8. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Circadian rhythm of platelet reactivity	Platelet reactivity will be measured by VerifyNow-aspirin assay, serum thromboxane B2, and flow-cytometry.	24hour rhythm of platelet reactivity	No