MONDAY, Jan. 16, 2017 (HealthDay News) — In non-obese European and American men, aged 19 to 39 years, the harmonized normal range of testosterone is 264 to 916 ng/dL (2.5th to 97.5th percentile), according to a study published online Jan. 10 in the Journal of Clinical Endocrinology & Metabolism.
Thomas G. Travison, Ph.D., from Harvard Medical School in Boston, and colleagues used data from 9,054 community-dwelling men in cohort studies in the United States and Europe to establish harmonized reference ranges for total testosterone that can be applied across laboratories. In each of four cohorts, testosterone concentrations were measured in 100 participants using a reference method. Normalizing equations were employed to generate harmonized values, which were used to derive standardized, age-specific reference ranges.
The researchers found that inter-cohort variation between testosterone measurements in men of similar ages was reduced with the harmonization procedure. The harmonized 2.5th, 5th, 50th, 95th, and 97.5th percentile values were 264, 303, 531, 852, and 916 ng/dL, respectively, in healthy non-obese men, aged 19 to 39 years. In non-obese men, age-specific harmonized testosterone concentrations were similar across cohorts and greater than in all men.
“A substantial proportion of inter-cohort variation in testosterone levels is due to assay differences,” the authors write. “These data demonstrate the feasibility of generating harmonized reference ranges for testosterone that can be applied to assays, which have been calibrated to a reference method and calibrator.”
Several authors disclosed financial ties to the pharmaceutical industry.
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