Melatonin Reduces Blood Pressure and Regulates Disrupted Circadian Rhythms in The Elderly

18 May 2016 --- Russian research has found that daily Melatonin administration reduces blood pressure and regulates age-dependent disturbances of circadian rhythms.

Increased blood pressure and reduced robustness of circadian rhythms are frequently reported in elderly subjects. The present study was aimed to investigate whether such changes can be reversed by daily melatonin ingestion.

Circadian rhythms are more likely to be disrupted with age. Blood pressure (BP), not only tends to increase but also becomes more irregular. However, research has found that melatonin helps to ameliorate both trends.

Denis G Gubin from Tyumen State Medical University, Russia led the study.

63 respondents with a mean age of 80 were studied during three consecutive weeks. In the first week, control data were collected for seven successive days. Over the next two weeks, the seniors were administered a low dose of melatonin (1.5 mg) each night at 10:30 p.m. On the third week the data were monitored again.

The findings, published in the journal Current Aging Science, showed that Melatonin significantly reduced BP. The hypotensive effect was dependent on time. The maximum systolic BP lowering effect of melatonin falls between 3:00 and 8:00 in the morning – the time of the highest risk of heart attacks and strokes. Nighttime and morning BP decreased more profoundly on average -8/3.5 mm Hg for SBP/DBP, respectively.

Mean systolic BP was highest during the first week, it decreased more on the second week of melatonin administration. Melatonin also decreased the overall variability in BP.

Melatonin was effective in synchronizing disrupted circadian rhythms of BP, heart rate and body temperature, making these circadian rhythms smoother and less irregular. None of these effects was found in 34 placebo treated seniors, thus ruling out the possibility that rhythms could be improved just because of regular schedule and presence of medical personnel who took measurements.

In conclusion, melatonin can be of great value for aged people suffering from hypertension as an adjuvant substance complementing basic medication as it is able to stabilize circadian BP, heart rate profiles and their phase relationships. The improvement of circadian pacemaker functions may also provide a new strategy in the treatment of hypertension.