Effect of melatonin on nocturnal blood pressure: meta-analysis of randomized controlled trials

Vasc Health Risk Manag. 2011;7:577-84. doi: 10.2147/VHRM.S24603. Epub 2011 Sep 15.

Abstract

Background: Patients with nocturnal hypertension are at higher risk for cardiovascular complications such as myocardial infarction and cerebrovascular insult. Published studies inconsistently reported decreases in nocturnal blood pressure with melatonin.

Methods: A meta-analysis of the efficacy and safety of exogenous melatonin in ameliorating nocturnal blood pressure was performed using a random effects model of all studies fitting the inclusion criteria, with subgroup analysis of fast-release versus controlled-release preparations.

Results: Seven trials (three of controlled-release and four of fast-release melatonin) with 221 participants were included. Meta-analysis of all seven studies did not reveal significant effects of melatonin versus placebo on nocturnal blood pressure. However, subgroup analysis revealed that controlled-release melatonin significantly reduced nocturnal blood pressure whereas fast-release melatonin had no effect. Systolic blood pressure decreased significantly with controlled-release melatonin (-6.1 mmHg; 95% confidence interval [CI] -10.7 to -1.5; P = 0.009) but not fast-release melatonin (-0.3 mmHg; 95% CI -5.9 to 5.30; P = 0.92). Diastolic blood pressure also decreased significantly with controlled-release melatonin (-3.5 mmHg; 95% CI -6.1 to -0.9; P = 0.009) but not fast-release melatonin (-0.2 mmHg; 95% CI -3.8 to 3.3; P = 0.89). No safety concerns were raised.

Conclusion: Add-on controlled-release melatonin to antihypertensive therapy is effective and safe in ameliorating nocturnal hypertension, whereas fast-release melatonin is ineffective. It is necessary that larger trials of longer duration be conducted in order to determine the long-term beneficial effects of controlled-release melatonin in patients with nocturnal hypertension.

Keywords: melatonin; meta-analysis; nocturnal blood pressure.

Publication types

  • Meta-Analysis
  • Review
  • Video-Audio Media

MeSH terms

  • Adult
  • Aged
  • Antihypertensive Agents / adverse effects
  • Antihypertensive Agents / therapeutic use*
  • Blood Pressure / drug effects*
  • Circadian Rhythm*
  • Delayed-Action Preparations
  • Drug Therapy, Combination
  • Evidence-Based Medicine
  • Female
  • Humans
  • Hypertension / drug therapy*
  • Hypertension / physiopathology
  • Male
  • Melatonin / adverse effects
  • Melatonin / therapeutic use*
  • Middle Aged
  • Randomized Controlled Trials as Topic*
  • Treatment Outcome
  • Young Adult

Substances

  • Antihypertensive Agents
  • Delayed-Action Preparations
  • Melatonin