Spring snow lowers human melatonin

Article English OPEN
Leppäluoto, Juhani ; Sikkilä, Kirsti ; Meyer-Rochow, Victor Benno ; Hassi, Juhani (2004)
  • Publisher: Co-Action Publishing
  • Journal: International Journal of Circumpolar Health (issn: 1797-237X, eissn: 1239-9736)
  • Related identifiers: doi: 10.3402/ijch.v63i0.17888
  • Subject: urinary melatonin, seasonal, annual, biorhythm, solar irradiance, visual perception

Objectives. We set out to find out in which way seasonal changes of environmental luminosity could affect melatonin secretion in humans. Study design. For an entire year we collected every two months nocturnal urine samples from 20 male outdoor workers who lived and worked in an area of the circumpolar region from which exact data of solar irradiance and temperature were available. Methods. Melatonin secretion rates were assessed with our melatonin-specific radioimmunoassay. Results. Melatonin secretion was twice as high in December as in April, 0.88 ± 16 nmol/12 h (mean ± SE) vs. 0.43 ± 9 nmol/12 h, p < 0.05. Regression analyses showed that melatonin values best correlated inversely with solar irradiance reflected off the ground (the so-called ‘albedo’). A tenfold increase in albedo for 1-4 weeks before the urine samplings were collected was associated with a ca. 50% reduction in melatonin secretion. The association with global irradiance was weaker and none existed with temperature or other environmental variables. Discussion. Light reaching the eyes via the snow or other reflecting surfaces appears to be most effective. These results help us to understand some of the mechanisms involved in certain biological phenomena that exhibit seasonal variations such as reproductive and selfdestructive behaviours.Keywords: urinary melatonin, seasonal, annual, biorhythm, solar irradiance, visual perception
  • References (14)
    14 references, page 1 of 2

    1. Beck-Friis J, von Rosen D, Kjellman BF, Ljunggren JG, Wetterberg L. Melatonin in relation to body measures, sex, age, season and the use of drugs in patients with major affective disorders and healthy subjects. Psychoneuroendocrinology 1984;9(3):261-277.

    2. Stokkan KA, Reiter RJ. Melatonin rhythms in Arctic urban residents. J Pineal Res 1994;16(1):33-36.

    3. Broadway J, Arendt J, Folkard S. Bright light phase shifts the human melatonin rhythm during the Antarctic winter. Neurosci Lett 1987;79(1-2):185-189.

    4. Yoneyama S, Hashimoto S, Honma K. Seasonal changes of human circadian rhythms in Antarctica. Am J Physiol 1999;277(4 Pt 2):R1091-1097.

    5. Vakkuri O, Leppäluoto J, Vuolteenaho O. Development and validation of a melatonin radioimmunoassay using radioiodinated melatonin as tracer. Acta Endocrinol (Copenh) 1984;106(2):152-157.

    6. Meyer-Rochow VB. Risks, especially for the eye, emanating from the rise of solar UV-radiation in the Arctic and Antarctic regions. Int J Circumpolar Health 2000;59(1):38-51.

    7. Näyhä S. Short and medium-term variations in mortality in Finland. Scand J Soc Med Suppl. 1981;21:1-101.

    8. Maes M, Cosyns P, Meltzer HY, De Meyer F, Peeters D. Seasonality in violent suicide but not in nonviolent suicide or homicide. Am J Psychiatry 1993;150(9): 1380-1385.

    9. Souêtre E,Wehr TA, Douillet P, Darcourt G. Influence of environmental factors on suicidal behavior. Psychiatry Res 1990;32(3):253-263.

    10. Linkowski P, Martin F, De Maertelaer V. Effect of some climatic factors on violent and non-violent suicides in Belgium. J Affect Disord 1992;25(3):161-166.

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