1. Contributors to the substantial variation in on-treatment testosterone levels in men receiving transdermal testosterone gels in randomized trials
- Author
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Shehzad Basaria, Shalender Bhasin, Karol M. Pencina, H. Ouyang, Venkatesh Krishnan, L. O'Brien, James G. MacKrell, and Thomas G. Travison
- Subjects
Adult ,Male ,medicine.medical_specialty ,Randomization ,Hormone Replacement Therapy ,Urology ,Endocrinology, Diabetes and Metabolism ,030204 cardiovascular system & hematology ,Hematocrit ,Administration, Cutaneous ,Target range ,Polymorphism, Single Nucleotide ,law.invention ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Endocrinology ,Sex hormone-binding globulin ,Randomized controlled trial ,law ,Sex Hormone-Binding Globulin ,Internal medicine ,medicine ,Humans ,Eunuchism ,Testosterone ,030212 general & internal medicine ,Aged ,Randomized Controlled Trials as Topic ,Transdermal ,Creatinine ,biology ,medicine.diagnostic_test ,business.industry ,Aldo-Keto Reductase Family 1 Member C3 ,Testosterone (patch) ,Middle Aged ,Reproductive Medicine ,chemistry ,Androgens ,biology.protein ,business ,Gels - Abstract
Summary There is substantial inter-individual variability in serum testosterone levels in hypogonadal men treated with testosterone gels. We aimed to elucidate participant-level factors that contribute to inter-individual variability in testosterone levels during testosterone therapy. An exploratory aim was to determine whether polymorphisms in genes encoding testosterone-metabolizing enzymes could explain the variation in on-treatment testosterone concentrations in men who were randomized to testosterone arm in TOM Trial. We used data from three randomized trials that used 1% transdermal testosterone gels and had testosterone levels measured 2–4 weeks after randomization for dose adjustment: Testosterone in Older Men with Mobility Limitation (TOM), Effects of Testosterone on Pain Perception (TAP), and Effects of Testosterone on Atherosclerosis Progression (TEAAM). Forty-seven percent, 38%, and 9% of participants in TAP, TEAAM, and TOM trials, respectively, failed to raise testosterone levels >400 ng/dL; 6, 8, and 30% of participants had on-treatment testosterone levels >1000 ng/dL. Even after dose adjustment, there was substantial variation in on-treatment levels at subsequent study visits. Baseline characteristics (age, height, weight, baseline testosterone, SHBG, hematocrit, and creatinine) accounted for only a small fraction of the variance (
- Published
- 2017
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