title: Interpreting laboratory results in transgender patients on hormone therapy.
abstract: BACKGROUND
  Clinical guidelines recommend laboratory monitoring of transgender persons on cross-sex hormone therapy, but gender-specific reference intervals leave clinicians with the dilemma of deciding what is "normal" for each patient. The goal of this study was to identify consistent changes in measurands with hormone therapy and determine which reference interval is appropriate.
  
  
  METHODS
  Laboratory data were abstracted from the medical records of 55 male-to-female patients on hormone therapy and compared with 20 male and 20 female nontransgender subjects.
  
  
  RESULTS
  Hemoglobin, hematocrit, and low-density lipoprotein resembled female values (P < .005), while alkaline phosphatase, potassium, and creatinine resembled male values (P < .05). Triglycerides were higher (P < .005) than either the male or female groups. The remainder of the measurands showed no differences.
  
  
  CONCLUSIONS
  Use of correct reference intervals in interpreting laboratory results reduces the risk of testing-related diagnostic error. Preliminary data suggest that new reference intervals need to be established for transgender patients.
authors: Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Ga. Electronic address: tkrober@emory.edu.
authors: Tiffany K
authors: TK
authors: Roberts
authors: Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Ga.
authors: Colleen S
authors: CS
authors: Kraft
authors: Department of Pathology and Laboratory Medicine, University of California San Francisco, Calif.
authors: Deborah
authors: D
authors: French
authors: Department of Pathology and Laboratory Medicine, University of California San Francisco, Calif.
authors: Wuyang
authors: W
authors: Ji
authors: Department of Pathology and Laboratory Medicine, University of California San Francisco, Calif; San Francisco General Hospital & Trauma Center, Calif.
authors: Alan H B
authors: AH
authors: Wu
authors: Division of Endocrinology, Department of Medicine, Emory University School of Medicine, Atlanta, Ga.
authors: Vin
authors: V
authors: Tangpricha
authors: Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Ga.
authors: Corinne R
authors: CR
authors: Fantz
mesh_terms: D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood; D003404:Creatinine / Q000097:blood; D003951:Diagnostic Errors; D005260:Female; D012739:Gonadal Steroid Hormones / Q000008:administration & dosage*; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012016:Reference Values; D057829:Gender-Affirming Procedures; D063106:Transgender Persons; D014280:Triglycerides / Q000097:blood
chemical_list: D015415:Biomarkers; D008078:Cholesterol, LDL; D012739:Gonadal Steroid Hormones; D006454:Hemoglobins; D014280:Triglycerides; D003404:Creatinine; D000469:Alkaline Phosphatase; D011188:Potassium
keywords: Hormone therapy; Reference range; Transgender