Seasonal variation of salivary testosterone in men, normally cycling women, and women using hormonal contraceptives

Abstract

Humans’ endogenous testosterone concentrations vary over a number of temporal scales, with little known about variation longer than monthly cycles. Past studies of seasonal or circannual variation have principally used male participants and have produced inconsistent results. Thus, little is known about how testosterone concentrations fluctuate throughout the year, whether such variation differs between men and women, and whether there are influences of hormonal contraceptive use. The present study collected saliva samples from a large sample (N=718) of men and women, each collected at one time point within a relatively uniform distribution over a full calendar year. Both men and normally-cycling women displayed seasonal variation in salivary testosterone concentrations, such that testosterone concentrations are maximal in the fall and minimal in the summer. Notably, normally-cycling women had testosterone concentrations that were over 100% greater at their maximum in fall compared to their minimum in summer. Women using hormonal contraceptives not only had consistently lower endogenous testosterone concentrations, but also showed a flatter seasonal testosterone profile. The implications for studies of psychology and human behavioral endocrinology are discussed.

Confounding factors and genetic polymorphism in the evaluation of individual steroid profiling

“…Periodical variations in hormones concentrations are well established in different species and matrices 45. In humans, T is also subjected to these fluctuations, as is previously shown in serum,46 saliva47 and urine 48 49.…”

Genetic Influences on Pubertal Development and Links to Behavior Problems

“…Direct assays of hormones, particularly at a single point in time, may not provide more accurate assessment of pubertal processes than do measures of physical features (even by self report; Shirtcliff et al 2009). Hormone levels reflect more than pubertal development, including variations due to genes (Harris et al 1998), circadian, monthly, and seasonal rhythms, environmental factors (e.g., diet, exercise), and behavior itself (Carré 2009; Stanton et al 2011); responses to hormones also depend on other hormones that are present, and sensitivity of hormone receptors (Styne and Grumbach 2011). Furthermore, hormone assays are not straightforward (Handelsman and Wartofsky 2013; van Anders 2010).…”

Testosterone and sport: Current perspectives

“…Testosterone is also associated with reduced empathy (Hermans, Putman, & van Honk, 2006), reduced perception of negative emotions (van Honk et al, 2005), enhanced attention to social threat (van Honk et al, 1999), and enhanced amygdala responses to social threat (Hermans et al, 2008; but see also Stanton, Wirth, et al, 2009), which may promote an increased willingness and interest in attaining dominance over one's competitors independent of the consequences for one's competitors. Additionally, testosterone has been linked to increased risk-taking in economic domains (Stanton et al, 2011; van Honk et al, 2004, but see also Stanton, Mullette-Gillman et al 2011) and social domains (Mazur, 1995). Lastly, testosterone is associated with enhanced visuospatial ability (Aleman et al, 2004) which may provide greater abilities in the perceiving critical targets and navigating the physical sports environment, i.e., field, rink, or court.…”