madman
Super Moderator
Just to be clear up any confusion this is Fiers camps data for mFT reference ranges not the harmonized reference range being worked on by the CDC.
*Serum samples were analyzed from healthy men participating in the SIBLOS/SIBEX and EMAS studies, both population-based cohort studies
* mFT levels were measured in 867 men using ED LC-MS/MS as previously reported (1). Subsequently, 95% reference ranges were determined using the non-parametric method
Reference: 1. Fiers T, Wu F, Moghetti P, Vanderschueren D, Lapauw B, Kaufman JM. Reassessing Free-Testosterone Calculation by Liquid Chromatography–Tandem Mass Spectrometry Direct Equilibrium Dialysis. J Clin Endocrinol Metab. 2018;103(6). doi:10.1210/jc.2017-02360
ECE 2024 Poster Presentation
Introduction
Determination of serum (calculated) free testosterone (FT) in clinical practice has been suggested by several clinical guidelines for the diagnosis of male hypogonadism in men with borderline total T concentrations and in situations with altered sex hormone-binding globulin, as it correlates better with androgen exposure than total T. The gold-standard for the determination of FT levels is considered to be directly measured free testosterone (mFT) using equilibrium dialysis followed by mass spectrometry (ED LC-MS/MS). However, no widely accepted reference ranges are available for this clinical parameter. We established mFT reference ranges for healthy men aged 18 to 69 years.
Objective
To establish reference ranges for measured FT in serum of healthy adult men.
Methods
Reference ranges were determined following Clinical & Laboratory Standards Institute guideline C28-A3c per age decade. Serum samples were analyzed from healthy men participating in the SIBLOS/SIBEX and EMAS studies, both population-based cohort studies. Exclusion criteria were medications or conditions that affect sex steroid metabolism or a BMI larger than 35 kg/m2. mFT levels were measured in 867 men using ED LC-MS/MS as previously reported (1). Subsequently, 95% reference ranges were determined using the non-parametric method.
Results
We present 95% mFT age-stratified reference ranges. These reference ranges show an expected, decreasing trend of mFT with aging. Lower limits and median mFT decrease at a remarkably stable rate of, on average, 12% per decade up into the 6th decade of life. However, in the upper limit, a marked decrease of 25% occurs after 39 years, followed by smaller decreases of 6% per decade in older age categories.
Conclusion
We have determined mFT reference ranges in healthy men aged 25 to 69. These reference ranges are a first step to improving the framework for further development and integration of free testosterone measurements and calculations in clinical practice.
*Serum samples were analyzed from healthy men participating in the SIBLOS/SIBEX and EMAS studies, both population-based cohort studies
* mFT levels were measured in 867 men using ED LC-MS/MS as previously reported (1). Subsequently, 95% reference ranges were determined using the non-parametric method
Reference: 1. Fiers T, Wu F, Moghetti P, Vanderschueren D, Lapauw B, Kaufman JM. Reassessing Free-Testosterone Calculation by Liquid Chromatography–Tandem Mass Spectrometry Direct Equilibrium Dialysis. J Clin Endocrinol Metab. 2018;103(6). doi:10.1210/jc.2017-02360
ECE 2024 Poster Presentation
Introduction
Determination of serum (calculated) free testosterone (FT) in clinical practice has been suggested by several clinical guidelines for the diagnosis of male hypogonadism in men with borderline total T concentrations and in situations with altered sex hormone-binding globulin, as it correlates better with androgen exposure than total T. The gold-standard for the determination of FT levels is considered to be directly measured free testosterone (mFT) using equilibrium dialysis followed by mass spectrometry (ED LC-MS/MS). However, no widely accepted reference ranges are available for this clinical parameter. We established mFT reference ranges for healthy men aged 18 to 69 years.
Objective
To establish reference ranges for measured FT in serum of healthy adult men.
Methods
Reference ranges were determined following Clinical & Laboratory Standards Institute guideline C28-A3c per age decade. Serum samples were analyzed from healthy men participating in the SIBLOS/SIBEX and EMAS studies, both population-based cohort studies. Exclusion criteria were medications or conditions that affect sex steroid metabolism or a BMI larger than 35 kg/m2. mFT levels were measured in 867 men using ED LC-MS/MS as previously reported (1). Subsequently, 95% reference ranges were determined using the non-parametric method.
Results
We present 95% mFT age-stratified reference ranges. These reference ranges show an expected, decreasing trend of mFT with aging. Lower limits and median mFT decrease at a remarkably stable rate of, on average, 12% per decade up into the 6th decade of life. However, in the upper limit, a marked decrease of 25% occurs after 39 years, followed by smaller decreases of 6% per decade in older age categories.
Age category (years) | Median mFT (ng/dl) | 95% mFT reference range (ng/dl) |
18-29 (n=140) | 12.0 | 6.7-25.3 |
40-49 (n=207) | 8.1 | 4.3.14.2 |
50-59 (n=146) | 7.1 | 3.8-12.8 |
60-69 (n=126) | 6.4 | 3.4-11.7 |
70-79 (n=125) | 5.6 | 2.7-8.7 |
Conclusion
We have determined mFT reference ranges in healthy men aged 25 to 69. These reference ranges are a first step to improving the framework for further development and integration of free testosterone measurements and calculations in clinical practice.
