The influence of melatonin supplementation on circadian pattern of blood pressure in patients with coronary artery disease--preliminary report

Melatonin--sleep-inducing remedy was reported to be implicated in "biological clock" of circulatory system. The deficits of this pineal hormone were observed in patients with coronary artery disease (CAD) and those with abnormal circadian pattern of blood pressure (BP). We hypothesize that melatonin supplementation could be beneficial for this group of patients thanks to return from "non-dippers" to physiological "dippers" group, which is characterized by lower rate of left ventricle hypertrophy and/or number of ischemic episodes, in comparison with "non-dippers". The aim of this study was to assess safety and the effects of melatonin treatment in patients with CAD and impaired circadian pattern of BP. INVESTIGATED GROUP AND METHODS: Thirty-nine ambulatory patients (69% males, mean age 61+/-5,0), with CAD confirmed by coronary angiography and with circadian pattern of BP classified in 24 hour ambulatory blood pressure monitoring (ABPM) as "non-dippers" were included into the study. All study participants, apart of previous treatment, started to use 5 mg melatonin before sleep. Control 24h ABPM was performed after 30 days of such cure. The results of both ABPMs were compared using statistical methods. RESULTS: Melatonin supplementation improved circadian pattern of BP in one third (30,8%) of study group - they were classified in the second ABPM as "dippers". Despite a tendency to increase a day/night difference of average BP for 5,9%--a percentage of patients who remained in the group of "non-dippers" was 46,2%. Unfavourable effect of melatonin treatment was observed in 23% of patients: 15,4%--"extreme-dippers", 7,6% --"reverse-dippers". CONCLUSION: Twenty-four hour noninvasive blood pressure monitoring performed before and during melatonin cure is crucial by considering benefits and dangers of this treatment begun in purpose to modify impaired pattern of blood pressure in patients with coronary artery disease.