[Melatonin production in hypertonic patients during magnetic storms].

Aim: To study mechanisms of action of natural magnetic field of the Earth on arterial pressure (AP) and melatonin production in patients with essential hypertension (EH) stage II.
Material and Methods: Clinical, laboratory and device investigations covered 52 men with EH stage II (mean age 42 +/- 0.92 years) and 11 healthy men (mean age 23 +/- 1.46 years). Mean 24-hour, mean daytime, mean night systolic and diastolic pressures, 24-h index, time hypertensive index, standard deviation were registered. Melatonin was measured in the urine by radioimmunoassay. Geomagnetic situation was assessed by K-index (quiet--under 15, disturbed--15-25, magnetic storm--above 25).
Results: In hypertensive patients AP grew with growth of geomagnetic activity. In normal subjects AP remained normal. The 24-h rhythm of AP variability in hypertensives was normal. Magnetic storm affected melatonin production in EH patients noticeably: night and daytime production of melatonin was low. In normal subjects night melatonin production was high.
Conclusion: AH stage II patients respond to magnetic storm with maladaptation, i.e. a rise in AP and low melatonin production.