Science Advance: Melatonin Does Not Effect Nighttime Blood Pressure in African-Americans with Essential Hypertension

Frederic Rahbari-Oskoui, MD, Assistant Professor of Medicine, Division of Nephrology, Emory University

Hypertension and more particularly higher nighttime blood pressure are important risk factors for heart attacks and strokes. The frequency of these problems is higher in African-Americans. Melatonin is a natural hormone produced by the pineal gland in the brain that is secreted at night. Melatonin supplements are therefore used as a sleep aid. Melatonin has been shown to reduce nighttime blood pressure in Caucasians, but prior to the Atlanta Clinical & Translational Science Institute (ACTSI)-supported research by Frederic Rahbari-Oskoui, MD, Assistant Professor of Medicine, Division of Nephrology, Emory University, it had not been tested in African-Americans.

In a randomized, placebo-controlled clinical trial design, Dr. Rahbari-Oskoui and his team investigated the effect of oral melatonin intake on nighttime blood pressure in two groups of African-American patients with hypertension, at two different doses. The hypothesis was that melatonin would lower nighttime blood pressure. The study went on for 10 weeks, and 24-hour blood pressure monitoring, lab tests, and sleep studies were performed. In contrast to previously published data in Caucasians, the study showed no significant effect of melatonin on nighttime blood pressure compared to placebo, suggesting that important differences exist between African-American and Caucasians in their response to melatonin.

The ACTSI’s Clinical Research Network (CRN) provided outpatient clinical space, nursing for timed sample collection, conducted sleep studies and polysomnography at Wesley Woods Sleep Center, and core lab processing and storage. These findings were recently presented by Dr. Rahbari-Oskoui at the American Society of Hypertension Annual Scientific Meeting in May 2014.