title: Effect of testosterone administration on liver fat in older men with mobility limitation: results from a randomized controlled trial.
abstract: BACKGROUND
  Androgen receptor (AR) knockout male mice display hepatic steatosis, suggesting that AR signaling may regulate hepatic fat. However, the effects of testosterone replacement on hepatic fat in men are unknown. The aim of this study was to determine the effects of testosterone administration on hepatic fat in older men with mobility limitation and low testosterone levels who were participating in a randomized trial (the Testosterone in Older Men trial).
  
  
  METHODS
  Two hundred and nine men with mobility limitation and low total or free testosterone were randomized in the parent trial to either placebo or 10-g testosterone gel daily for 6 months. Hepatic fat was determined by magnetic resonance imaging in 73 men (36 in placebo and 37 in testosterone group) using the volumetric method. Insulin sensitivity (homeostatic model assessment-insulin resistance) was derived from fasting glucose and insulin.
  
  
  RESULTS
  Baseline characteristics were similar between the two groups, including liver volumes (1583 ± 363 in the testosterone group vs 1522 ± 271 mL in the placebo group, p = .42). Testosterone concentrations increased from 250 ± 72 to 632 ± 363 ng/dL in testosterone group but did not change in placebo group. Changes in liver volume during intervention did not differ significantly between groups (p = .5) and were not related to on-treatment testosterone concentrations. The change in homeostatic model assessment-insulin resistance also did not differ significantly between groups and was not related to either baseline or change in liver fat.
  
  
  CONCLUSIONS
  Testosterone administration in older men with mobility limitation and low testosterone levels was not associated with a reduction in hepatic fat. Larger trials are needed to determine whether testosterone replacement improves liver fat in men with nonalcoholic hepatic steatosis.
authors.affiliation: Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, 670 Albany Street, Boston, MA02118, USA.
authors.forename: Grace
authors.initials: G
authors.lastname: Huang
authors.forename: Shalender
authors.initials: S
authors.lastname: Bhasin
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Tang
authors.forename: Adam
authors.initials: A
authors.lastname: Aakil
authors.forename: Stephan W
authors.initials: SW
authors.lastname: Anderson
authors.forename: Hernan
authors.initials: H
authors.lastname: Jara
authors.forename: Maithili
authors.initials: M
authors.lastname: Davda
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Travison
authors.forename: Shehzad
authors.initials: S
authors.lastname: Basaria
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects* / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D005234:Fatty Liver / Q000097:blood / Q000188:drug therapy / Q000473:pathology; D006801:Humans; D007333:Insulin Resistance; D008099:Liver / Q000187:drug effects* / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D051346:Mobility Limitation; D013739:Testosterone / Q000008:administration & dosage* / Q000097:blood / Q000172:deficiency
chemical_list: D013739:Testosterone
keywords: Insulin resistance.; Liver fat; Older men; Testosterone