title: The effect of seasonal variation on sexual behaviors in males and its correlation with hormone levels: a prospective clinical trial.
abstract: BACKGROUND
  We examined the effect of seasonal variation on sexual behavior and its relationship with testosterone levels. The existence of the inhibiting effect of cold stress on sexual behavior and testosterone levels was our hypothesis.
  
  
  METHODS
  A total of 80 cases, aged between 20 and 35 years old, were enrolled. Blood samples for testosterone, FSH, LH, and prolactin were obtained twice from each participant at the same time of day (before 10 am). The first samples were taken in January and February, the months which have the average lowest heat days (-15.9°C and -14.6°C, respectively) in our region. The second samples were taken in July and August, which has the average highest heat days (25.4°C and 26.1°C, respectively) in our region. Two times IIEFs (International Index of Erectil Function) were fulfilled at the same day of taking blood samples. The frequency of sexual thoughts and ejaculation were questioned by asking "How many times did you imagine having sex?'' and "How many times did you ejaculate in a week?". The body mass index of the participants in the study was calculated in the winter and in the summer.
  
  
  RESULTS
  There were significant differences in terms of IIEF scores, frequency of sexual thoughts and ejaculations, BMI (Body mass index), and both testosterone and FSH levels between the winter and summer measurements. We did not find any significant differences with regards to prolactin and LH levels.
  
  
  CONCLUSIONS
  Although testosterone levels are within normal limits in both seasons, its level in cold months is less than in hot months. Testosterone levels can change according to the season. The impact of cold seasons in particular should be taken into account when evaluating testosterone levels and sexual status, as well as the other influences (social, cultural).
authors.affiliation: Kafkas University, Medical School, Department of Urology, Kars, Turkey.
authors.forename: Aslan
authors.initials: A
authors.lastname: Demir
authors.affiliation: Kafkas University, Medical School, Department of Urology, Kars, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Uslu
authors.affiliation: Kafkas University, Medical School, Department of Urology, Kars, Turkey.
authors.forename: Omer Erkam
authors.initials: OE
authors.lastname: Arslan
keywords: cold stress; seasonal variation; sexual behavior; testosterone