%0 Journal Article
%T The female menstrual cycle does not influence testosterone concentrations in male partners
%A Jakob O Strom
%A Edvin Ingberg
%A Emma Druvefors
%A Annette Theodorsson
%A Elvar Theodorsson
%J Journal of Negative Results in BioMedicine
%D 2012
%I BioMed Central
%R 10.1186/1477-5751-11-1
%X Thirty young, healthy, heterosexual couples were recruited. During the course of 30-40 days, the women registered menses and ovulation, while the men registered sexual activity, physical exercise, alcohol intake and illness (confounders), and obtained daily saliva samples for testosterone measurements. All data, including the registered confounders, were subjected to multiple regression analysis.In contrast to the hypothesis, the ovulation did not affect the testosterone levels, and the resulting testosterone profile during the menstrual cycle was on the average flat. The specific main hypothesis, that male testosterone levels on the day of ovulation would be higher than day 4 of the cycle, was clearly contradicted by a type II error(¦Â)-analysis (< 14.3% difference in normalized testosterone concentration; ¦Â = 0.05).Even though an ovulation-related salivary testosterone peak was observed in individual cases, no significant effect was found on a group level.Testosterone is by far the most potent naturally occurring androgen [1], and has over the years attracted considerable research efforts, e.g. for its behavioral and developmental effects [2] and its implications in aging [3,4]. The concentrations of testosterone are influenced by several factors, including endogenous cycling patterns such as a circadian cyclicity, rendering peak levels in the morning and nadir levels during the night [1], and the circannual variation with a peak in summer and a valley in winter/early spring [5,6]. Other infradian testosterone cycles between 6 and 33 days of lengths have also been proposed, as yet with limited support in scientific studies [7-12].A number of exogenous factors, such as lacrimal secretions, can influence the male testosterone concentrations [13], possibly reflecting pheromonal effects. It has further been demonstrated that sniffing a t-shirt that had been worn by an ovulating female caused a smaller reduction in testosterone levels than did smelling a t-shirt from a
%K Testosterone
%K Menstrual cycle
%K Ovulation
%K Salivary
%K Pheromones
%K Hormones
%U http://www.jnrbm.com/content/11/1/1