Conditions: Hypertension
Keywords: Melatonin Hypertension Blood Pressure Cardiovascular Sleep Nighttime Nocturnal Catecholamines Sympathetic Nervous System Endothelial Function African American
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 40
Healthy volunteers: yes

Brief summary:
The purpose of this study is to test the effect of oral melatonin supplementation (24 mg per night for 4 weeks) on nighttime blood pressure in African Americans with a history of elevated nighttime blood pressure.

Detailed description:
The main outcome of interest is the mean nighttime blood pressure. The investigator is also trying to see the mechanism of action of melatonin on blood pressure by analyzing data from sleep studies to see if melatonin lowers blood pressure by providing a better quality of sleep or is that independent of the quality of sleep.

The investigator is also looking into the effect of melatonin on sympathetic nervous system by measuring urinary catecholamines.

Finally, the investigator is looking into changes in vascular biology markers P-selectin and e-selectin) on Melatonin.

Arms:
arm 1: Subjects with mild to moderate essential hypertension will be given 24mg time release melatonin for 4 weeks either before or after exposure to 4 week of placebo with no washout period. arm 2: Subjects with mild to moderate essential hypertension will be given placebo for 4 weeks either before or after exposure to 4 weeks of 24mg daily dose of time release melatonin with no washout period.

Interventions: intervention 1: Melatonin intervention 2: Placebo
Intervention descriptions: intervention 1: Melatonin (N-acetyl-5-methoxytryptamine) is an indoleamine compound. Subjects will receive 24mg of time release melatonin pills (3 x 8mg) to be taken orally at night for 4 weeks. intervention 2: Subjects will receive placebo pills (3 pills) to be taken orally once per night for 4 weeks.

Protocol document: