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Geomagnetic activity influences the melatonin secretion at latitude 70 degrees N
A Weydahl1, R B Sothern, G Cornélissen
1Finnmark University College, Alta, Norway. andi@hifm.no
Biomedicine & Pharmacotherapy = Biomedecine & Pharmacotherapie
|January 5, 2002
Summary
Geomagnetic disturbances can impact melatonin secretion. Significant geomagnetic activity, especially in polar regions, was found to decrease salivary melatonin levels in healthy subjects.
Area of Science:
- Geophysics
- Chronobiology
- Endocrinology
Background:
- Melatonin secretion is primarily regulated by light-dark cycles.
- Geomagnetic field disturbances are more pronounced at high latitudes.
- The interplay between geomagnetic activity and circadian rhythms is not well understood.
Purpose of the Study:
- To investigate the influence of geomagnetic activity on melatonin secretion.
- To explore potential non-photic factors affecting circadian rhythms.
Main Methods:
- Saliva samples collected from 25 healthy subjects in Alta, Norway.
- Analysis of circadian rhythms using single cosinor.
- Correlation between melatonin levels and the local geomagnetic activity index (K).
Main Results:
- Both melatonin and geomagnetic activity (K index) exhibited circadian and circannual rhythms.
- Peak geomagnetic activity preceded peak melatonin secretion.
- High-magnitude geomagnetic disturbances (> 80 nT/3 h) significantly reduced salivary melatonin concentration.
Conclusions:
- Geomagnetic activity can influence melatonin secretion, particularly at high latitudes.
- Significant geomagnetic disturbances may suppress melatonin levels.
- This suggests a potential non-photic influence on circadian hormone regulation.
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