title: Testosterone replacement elevates the serum uric acid levels in patients with female to male gender identity disorder.
abstract: Gender identity disorder (GID) results from a disagreement between a person's biological sex and the gender to which he or she identifies. With respect to the treatment of female to male GID, testosterone replacement therapy (TRT) is available. The uric acid (UA) level can be influenced by testosterone; however, the early effects and dose-dependency of TRT on the serum UA concentration have not been evaluated in this population. We herein conducted a dose-response analysis of TRT in 160 patients with female to male GID. The TRT consisted of three treatment groups who received intramuscular injections of testosterone enanthate: 125 mg every two weeks, 250 mg every three weeks and 250 mg every two weeks. Consequently, serum UA elevation was observed after three months of TRT and there was a tendency toward testosterone dose-dependency. The onset of hyperuricemia was more prevalent in the group who received the higher dose. We also demonstrated a positive correlation between increased levels of serum UA and serum creatinine. Since the level of serum creatinine represents an individual's muscle volume and the muscle is a major source of purine, which induces UA upregulation, the serum UA elevation observed during TRT is at least partially attributed to an increase in muscle mass. This is the first study showing an association between serum UA elevation and a TRT-induced increase in muscle mass. The current study provides important information regarding TRT for the follow-up and management of the serum UA levels in GID patients.
authors.affiliation: Department of Urology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kurahashi
authors.forename: Masami
authors.initials: M
authors.lastname: Watanabe
authors.forename: Morito
authors.initials: M
authors.lastname: Sugimoto
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ariyoshi
authors.forename: Sabina
authors.initials: S
authors.lastname: Mahmood
authors.forename: Motoo
authors.initials: M
authors.lastname: Araki
authors.forename: Kazushi
authors.initials: K
authors.lastname: Ishii
authors.forename: Yasutomo
authors.initials: Y
authors.lastname: Nasu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nagai
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kumon
mesh_terms: D000328:Adult; D000728:Androgens / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics / Q000627:therapeutic use; D001823:Body Composition / Q000187:drug effects; D003404:Creatinine / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D020249:Hormone Replacement Therapy / Q000009:adverse effects; D006801:Humans; D033461:Hyperuricemia / Q000139:chemically induced* / Q000453:epidemiology; D007273:Injections, Intramuscular; D007564:Japan / Q000453:epidemiology; D009132:Muscles / Q000187:drug effects / Q000473:pathology; D015995:Prevalence; D012189:Retrospective Studies; D013739:Testosterone / Q000008:administration & dosage / Q000009:adverse effects* / Q000031:analogs & derivatives / Q000493:pharmacokinetics / Q000627:therapeutic use; D014189:Transsexualism / Q000097:blood / Q000188:drug therapy* / Q000473:pathology; D014527:Uric Acid / Q000097:blood*
chemical_list: D000728:Androgens; D014527:Uric Acid; D013739:Testosterone; C004648:testosterone enanthate; D003404:Creatinine