Melatonin is critical to maintaining our own circadian rhythms, the day and night cycles of rest and wakeful activity, but its value extends well beyond simply getting a good night’s sleep.
Melatonin levels affect your body’s ability to ward off infections, your resistance to stress and anxiety, and the strength of your heart and cardiovascular system.
In fact, low melatonin levels can be tied to hypertension (high blood pressure levels), a condition that often doesn’t have any symptoms until it results in a serious cardio episode. What’s more, when high blood pressure levels occur at night, you may be under even greater risk of heart attack or stroke.
Researchers reviewing clinical studies found that while at first glance, melatonin supplementation didn’t appear to have effects on blood pressure levels, digging a little deeper revealed a more complicated picture: the supplement needed to be a sustained-release form that delivers melatonin slowly. In studies that featured those forms, as opposed to immediate release supplements, blood pressure systolic (top) numbers and diastolic (bottom) numbers improved significantly.
A sustained release form of melatonin can be useful for many reasons, but for anyone concerned about their blood pressure levels, it appears to be the best choice, and an easy one to incorporate into a nightly regimen.
Grossman E, Laudon M, Zisapel N. Effect of melatonin on nocturnal blood pressure: meta-analysis of randomized controlled trials. Vasc Health Risk Manag. 2011;7:577-584. doi:10.2147/VHRM.S24603
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.
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.
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.
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.