title: Associations between Salivary Testosterone Levels, Androgen-Related Genetic Polymorphisms, and Self-Estimated Ejaculation Latency Time.
abstract: BACKGROUND
  Recently, testosterone (T) has been shown to be associated with premature ejaculation (PE) symptoms in the literature. Furthermore, studies suggest that the etiology of PE is partly under genetic control.
  
  
  OBJECTIVE
  The aim of this study was to reassess findings suggesting an association between testosterone (T) and a key symptom of PE, ejaculation latency time (ELT), as well as exploratively investigating associations between six androgen-related genetic polymorphisms and ELT.
  
  
  METHODS
  Statistical analyses were performed on a population-based sample of 1,429 Finnish men aged 18-45 years (M = 26.9, SD = 4.7). Genotype information was available for 1,345-1,429 of these (depending on the polymorphism), and salivary T samples were available from 384 men. Two androgen receptor gene-linked, two 5-alpha-reductase type 2-gene-linked, and two sex hormone-binding globuline gene-linked polymorphisms were genotyped.
  
  
  METHODS
  Ejaculatory function was assessed using self-reported ELT.
  
  
  RESULTS
  We found no association between salivary T levels and ELT. We found a nominally significant association between a 5-alpha-reductase type 2-gene-linked polymorphism (rs2208532) and ELT, but this association did not remain significant after correction for multiple testing. One single nucleotide polymorphism in the sex hormone-binding globulin gene (rs1799941) moderated (significantly after correction for multiple testing) the association between salivary T and ELT, so that A:A genotype carriers had significantly lower salivary T levels as a function of increasing ELT compared with other genotype groups.
  
  
  CONCLUSIONS
  We were unable to find support for the hypothesis suggesting an association between T levels and ELT, possibly because of the low number of phenotypically extreme cases (the sample used in the present study was population based). Our results concerning genetic associations should be interpreted with caution until replication studies have been conducted. Jern P, Westberg L, Ankarberg-Lindgren C, Johansson A, Gunst A, Sandnabba NK, and Santtila P. Associations between salivary testosterone levels, androgen-related genetic polymorphisms, and self-estimated ejaculation latency time. Sex Med 2014;2:107-114.
authors.affiliation: Genetic Epidemiology Laboratory, QIMR Berghofer Medical Research Institute Herston, Queensland, Australia ; Department of Behavioral Sciences and Philosophy, University of Turku Turku, Finland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Jern
authors.affiliation: Department of Pharmacology, Sahlgrenska Academy, University of Gothenburg Gothenburg, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Westberg
authors.affiliation: Göteborg Pediatric Growth Research Center, Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg Gothenburg, Sweden.
authors.forename: Carina
authors.initials: C
authors.lastname: Ankarberg-Lindgren
authors.affiliation: Genetic Epidemiology Laboratory, QIMR Berghofer Medical Research Institute Herston, Queensland, Australia ; Department of Psychology and Logopedics, Abo Akademi University Turku, Finland.
authors.forename: Ada
authors.initials: A
authors.lastname: Johansson
authors.affiliation: Department of Psychology and Logopedics, Abo Akademi University Turku, Finland.
authors.forename: Annika
authors.initials: A
authors.lastname: Gunst
authors.affiliation: Department of Psychology and Logopedics, Abo Akademi University Turku, Finland.
authors.forename: N Kenneth
authors.initials: NK
authors.lastname: Sandnabba
authors.affiliation: Department of Psychology and Logopedics, Abo Akademi University Turku, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Santtila
keywords: SNP; androgen; ejaculation; genetic; polymorphism; premature ejaculation; testosterone