Melatonin and Nighttime Blood Pressure in African Americans

• Daytime ambulatory blood pressure [ Time Frame: After 4 weeks of treatment ] [ Designated as safety issue: No ]
• Sleep duration and quality [ Time Frame: After 4 weeks of treatment ] [ Designated as safety issue: No ]
• Urinary catecholamines [ Time Frame: After 4 weeks of treatment ] [ Designated as safety issue: No ]
• Markers of endothelial function [ Time Frame: After 4 weeks of treatment ] [ Designated as safety issue: No ]
• Melatonin-related side effects [ Time Frame: After 4 weeks of treatment ] [ Designated as safety issue: Yes ]

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.

• Drug: 8 mg time-release melatonin pills
  8 mg time-release melatonin pills, once per night for 4 weeks
• Drug: Placebo pills
  Placebo pills, once per night for 4 weeks

• Active Comparator: 8 mg time release melatonin pills
  Intervention: Drug: 8 mg time-release melatonin pills
• Placebo Comparator: Placebo pills
  Intervention: Drug: Placebo pills

Inclusion Criteria:

• Males or females ages 18 to 64
• Prior history of elevated nighttime BP (>125 mmHg SBP)
• Taking no more than 2 antihypertensive medications
• African-American race (self-defined by the participant)

Exclusion Criteria:

• Secondary forms of hypertension
• Presence of other diseases requiring treatment with BP lowering medications
• Known cardiovascular disease (including history of angina pectoris, heart failure, presence of a cardiac pacemaker, history of myocardial infarction or revascularization procedure, or cerebrovascular disease, including stroke and TIA)
• Diabetes mellitus (type 1 or 2)
• Cancer/Malignancy other than nonmelanoma skin cancer
• Primary renal disease
• Serum creatinine > 1.5 in men or > 1.4 in women
• Severe anemia
• Liver enzymes > 2.5 upper limits of normal
• Hepatitis B, Hepatitis C, or HIV positive as assessed by questionnaire
• Current treatment with or regular use of calcium channel blocking agents, COX2-inhibitors, oral contraceptives, estrogen, sildenafil, vardenafil, tadalafil, antidepressants, corticosteroids, or warfarin
• Current use of melatonin or any sleep aids containing melatonin.
• Regular consumption (1 or more times per week) of any of the following of Vitamin methyl B12, St.

Johns Wort, Feverfew, black and white mustard seeds, wolf berry seed

• Sleep apnea
• Night work
• Women who are pregnant, breast-feeding, attempting conception, or planning to attempt conception over the next 6 months.