Weather conditions: a neglected factor in human salivary cortisol research?
There is ample evidence that environmental stressors such as extreme weather conditions affect animal behavior and that this process is in part mediated through the elevated activity of the hypothalamic pituitary adrenal axis which results in an increase in cortisol secretion. This relationship has not been extensively researched in humans, and weather conditions have not been analyzed as a potential confounder in human studies of stress. Consequently, the goal of this paper was to assess the relationship between salivary cortisol and weather conditions in the course of everyday life and to test a possible moderating effect of two weather-related variables, the climate region and timing of exposure to outdoors conditions. The sample consisted of 903 secondary school students aged 18 to 21 years from Mediterranean and Continental regions. Cortisol from saliva was sampled in naturalistic settings at three time points over the course of a single day. We found that weather conditions are related to salivary cortisol concentration and that this relationship may be moderated by both the specific climate and the anticipation of immediate exposure to outdoors conditions. Unpleasant weather conditions are predictive for the level of salivary cortisol, but only among individuals who anticipate being exposed to it in the immediate future (e.g., in students attending school in the morning shift). We also demonstrated that isolated weather conditions or their patterns may be relevant in one climate area (e.g., Continental) while less relevant in the other (e.g., Mediterranean). Results of this study draw attention to the importance of controlling weather conditions in human salivary cortisol research.
KeywordsSalivary cortisol HPA axis activity Weather conditions Climate Naturalistic study
This study (CLASS) was taken with the framework of the project “Modernity Stress, Youth and Modernization” (09.01/408) financed by the Croatian Science Foundation, awarded to Dr. Irena Martinović Klarić. We are thankful to the Croatian Meteorological and Hydrological Service for providing meteorological data and especially to Mrs. Dubravka Rasol and Mr. Damir Mlinek for their kind assistance. We sincerely thank to Dr. Natasha Levak for proofreading of the manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Agrimonti F, Angeli A, Frairia R, Fazzari A, Tamagnone C, Fornaro D et al (1982) Circannual rhythmicities of cortisol levels in the peripheral plasma of healthy subjects. Chronobiologia 9:107–114Google Scholar
- Aiken LS, West SG (1991) Multiple regression: testing and interpreting interactions. Sage, Thousand OaksGoogle Scholar
- Buss DM (2008) Evolutionary psychology: the new science of the mind. Pearson, BostonGoogle Scholar
- Cook TD, Campbell DT (1979) Quasi-experimentation: design and analysis issues for field settings. Houghton Mifflin Company, BostonGoogle Scholar
- Cunningham MR (1979) Weather, mood, and helping behavior: quasi experiments with the sunshine Samaritan. J Pers Soc Psychol 37:1974–1956Google Scholar
- Gesquiere LR, Khan M, Shek L, Wango TL, Wango EO, Alberts SC et al (2008). Coping with a challenging environment: effects of seasonal variability and reproductive status on glucocorticoid concentrations of female baboons (Papio cynocephalus). Horm Behav 54:410–416Google Scholar
- Hair JF, Black WC, Babin BJ, Anderson RE (2009) Multivariate data analysis. Prentice Hall, Upper Saddle RiverGoogle Scholar
- Hansen AM, Persson R, Garde AH, Karlson B, Orbaek P (2006) Diurnal profiles of salivary cortisol on workdays among construction workers versus white-collar workers. Scand J Work Environ Health Suppl 2:22–26Google Scholar
- Jonsdottir I, Halford C, Eek F (2012) Mental health and salivary cortisol In: Kristenson M, Garvin P, Lundberg U (eds) The role of saliva cortisol measurements in health and disease. Bentham E Books, pp 129–166. https://ebooks.benthamscience.com/book/9781608053421/
- Phillips DIW, Barker DJP, Fall CHD, Seckl JR, Whorwood CB, Wood PJ et al (1998) Elevated plasma cortisol concentrations: a link between low birth weight and insulin resistance syndrome? J Clin Endocrinol Metab 83:757–760Google Scholar
- Reinberg A, Lagoguey M, Cesselin F, Touitou Y, Legrand JC, Delassalle A et al (1978) Circadian and circannual rhythms in plasma hormones and other variables of five healthy young human males. Acta Endocrinol 88:417–427Google Scholar
- Sterling P, Eyer J (1988) Allostasis: a new paradigm to explain arousal pathology. In: Fisher S, Reason J (eds) Handbook of life stress, cognition and health. Wiley, New York, pp 629–649Google Scholar
- Šupe-Domić D, Milas G, Drmić-Hofman I, Rumora L, Martinović Klarić I (2016) Daily salivary cortisol profile: insights from the Croatian Late Adolescence Stress Study (CLASS). Biochem Med 26:408–420Google Scholar
- Walker BR, Best R, Noon JP, Watt GCM, Webb DJ (1997) Seasonal variation in glucocorticoid activity in healthy men. J Clin Endocrinol Metab 82:4015–4019Google Scholar