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: 37
Healthy volunteers: yes

Brief summary:
This purpose of this study is to test the effect of oral melatonin supplementation (8 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: African-American subjects with mild to moderate essential hypertension will be given 8mg time release melatonin for 4 weeks. (either before or after placebo exposure). arm 2: African-American subjects with mild to moderate essential hypertension will be given placebo for 4 weeks (either before or after exposure to melatonin)

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

Protocol document: