Get started
Work

Serum Testosterone (T) Level Variability in T Gel-Treated Older Hypogonadal Men: Treatment Monitoring Implications

Year: 2015
Type: article
Study design: Clinical Trial
Abstract: CONTEXT: The optimal frequency for on-treatment serum T measurement used for dose adjustment after transdermal T gel application is unknown, especially in older men with thinner skin and slower metabolic clearance. OBJECTIVES: The objectives of the study was to determine the variability of postgel application serum T concentrations and assess whether single levels are reflective of average serum T concentrations over 24 hours (Cavg0-24). DESIGN: This was a double-blinded, placebo-controlled randomized trial. SETTING: The study was conducted at five academic centers. PARTICIPANTS: Forty-seven symptomatic men 65 years old or older with an average of two morning T concentration less than 275 ng/dL participated in the study. INTERVENTION(S): Transdermal T or placebo gel was applied for 120 ± 14 days. Monthly dose adjustments were made if necessary to target serum T between 400 and 500 to 800 ng/dL. MAIN OUTCOME MEASURES: Variability of serum T 2 hours after the gel application on two outpatient visits and at multiple time points over 24 hours during the inpatient day was measured. RESULTS: On-treatment T levels varied substantially on the 2 ambulatory days and over 24 hours during the inpatient day. Ambulatory 2-hour postapplication T levels did not correlate significantly with either 2-hour postapplication serum T or Cavg0-24 measured during the inpatient day. Only 22.2% of men receiving T had a Cavg0-24 within the target range of 500-800 ng/dL; 81.5% had a Cavg0-24 within the broader 300-1000 ng/dL range. CONCLUSION: Large within-individual variations in serum T after T gel application render ambulatory 2-hour postapplication T level a poor indicator of average serum T on another day. Our data point out the limitations of dose adjustments based on a single postapplication serum T measurement.
DOI: 10.1210/jc.2015-1542
Authors: Ronald S. Swerdloff, Youngju Pak, Christina Wang, Peter Y. Liu, Shalender Bhasin, Thomas M. Gill, Alvin M. Matsumoto, Marco Pahor, Prasanth Surampudi, Peter J. Snyder
Institutions: Brigham and Women's Hospital, Harvard University, University of California, Los Angeles, The Lundquist Institute, University of Washington, Yale University, University of Florida, Harbor–UCLA Medical Center, University of Pennsylvania, VA Puget Sound Health Care System
Language: English
Field: Medicine
Open Access status: green
Funders: U.S. Department of Veterans Affairs, National Institutes of Health, National Institute on Aging, National Institute of Diabetes and Digestive and Kidney Diseases, National Center for Research Resources, National Center for Advancing Translational Sciences
Awards: Testerone Trial, G2408971297, UCLA Clinical and Translational Science Institute, Endocrinology, Metabolism and Nutrition Training Grant, ACADEMIC LEADERSHIP AWARD IN DISABILITY AND DISABLING DISORDERS, G5659566681, Boston University Clinical and Translational Science Award (CTSA) Program UL1, Yale University Clinical and Translational Science Award Program, Boston OAIC: A Translational Approach to Function Promoting Therapies, University of Florida Older Americans Independence Center (OAIC), Claude D. Pepper Older Americans Independence Center at Yale
OpenAlex ID: W2120319122
FWCI: 5.784
Cites: 25
Cited by: 39
Related to: 10