title: Testosterone in human studies: Modest associations between plasma and salivary measurements.
abstract: Testosterone is involved in many processes like aggression and mood disorders. As it may easily diffuse from blood into saliva, salivary testosterone is thought to reflect plasma free testosterone level. If so, it would provide a welcome noninvasive and less stressful alternative to blood sampling. Past research did not reveal consensus regarding the strength of the association, but sample sizes were small. This study aimed to analyse the association in a large cohort. In total, 2,048 participants (age range 18-65 years; 696 males and 1,352 females) were included and saliva (using cotton Salivettes) and plasma were collected for testosterone measurements. Levels were determined by enzyme-linked immunosorbent assay and radioimmunoassay respectively. Free testosterone was calculated by the Vermeulen algorithm. Associations were determined using linear regression analyses. Plasma total and free testosterone showed a significant association with salivary testosterone in men (adjusted β = .09, p = .01; and β = .15, p < .001, respectively) and in women (adjusted β = .08, p = .004; and crude β = .09, p = .002 respectively). The modest associations indicate that there are many influencing factors of both technical and biological origin.
authors.affiliation: Department of Psychiatry, University of Groningen, Groningen, The Netherlands.
authors.forename: A E
authors.initials: AE
authors.lastname: de Wit
authors.affiliation: Department of Psychiatry, University of Groningen, Groningen, The Netherlands.
authors.forename: F J
authors.initials: FJ
authors.lastname: Bosker
authors.affiliation: Department of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: E J
authors.initials: EJ
authors.lastname: Giltay
authors.affiliation: Department of Psychiatry, Centrum'45, Oegstgeest, The Netherlands.
authors.forename: C S
authors.initials: CS
authors.lastname: de Kloet
authors.affiliation: Behavioural Science Institute and Donders Institute for Brain Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands.
authors.forename: K
authors.initials: K
authors.lastname: Roelofs
authors.affiliation: Laboratorium KCHI, Medisch Centrum Alkmaar, Alkmaar, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: van Pelt
authors.affiliation: Department of Psychiatry, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: B W J H
authors.initials: BWJH
authors.lastname: Penninx
authors.affiliation: Department of Psychiatry, University of Groningen, Groningen, The Netherlands.
authors.forename: R A
authors.initials: RA
authors.lastname: Schoevers
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D012463:Saliva / Q000737:chemistry*; D013739:Testosterone / Q000032:analysis* / Q000097:blood; D055815:Young Adult
chemical_list: D013739:Testosterone
keywords: associations; large cohort; plasma; saliva; testosterone