Men's Health Boston, Harvard Medical School, Boston, MA, USA.
J Sex Med. 2010 May;7(5):1948-53. doi: 10.1111/j.1743-6109.2009.01473.x. Epub 2009 Sep 1.
The most widely used method for measuring free testosterone (FT) is by analog immunoassay (aFT); however, this assay has been criticized as unreliable based on laboratory studies in small groups of men. Calculated FT (cFT), derived from total testosterone (TT) and sex-hormone binding globulin (SHBG) values has been recommended in its place. There are limited data comparing aFT and cFT in clinical populations.
The purpose of this study was to compare aFT with cFT in a population of ambulatory men in a clinical setting.
Medical records were reviewed for 100 randomly selected men in a urology practice, yielding 140 test results complete for TT, aFT, and SHBG. Calculated FT was determined via an online calculator. Comparisons were made with Pearson rank coefficients.
Pearson rank correlation between aFT and cFT.
Mean patient age was 52.3 +/- 14.3 years (range 24-80). Mean TT was 443.0 +/- 208.3 ng/dL (range 110-1276). Mean aFT was 1.22 +/- 0.54 ng/dL (range 0.24-3.8) and mean cFT 9.4 +/- 4.5 ng/dL (range 1.8-27.8). Mean SHBG was 34.2 +/- 19.5 nmol/L (range 9-127). A strong correlation was observed for aFT and cFT (r = 0.88, P < 0.0001), particularly at low concentrations. Significant correlations were also noted between aFT and TT (r = 0.73, P < 0.0001), and between cFT and TT (r = 0.82, P < 0.0001). Numerical values for aFT were approximately one-eighth of the values obtained for cFT. Neither aFT nor cFT correlated with SHBG.
A strong correlation was observed between aFT and cFT in this clinical population of ambulatory men. Different sets of reference values must be applied for each of these tests.
测量游离睾酮（FT）最常用的方法是采用模拟免疫分析（aFT）；然而，基于对小部分男性的实验室研究，这种检测方法已被认为不可靠。计算得出的 FT（cFT），由总睾酮（TT）和性激素结合球蛋白（SHBG）值计算得出，已被推荐替代 aFT。在临床人群中，比较 aFT 和 cFT 的数据有限。
本研究旨在比较临床环境中门诊男性人群中的 aFT 和 cFT。
对泌尿科诊所的 100 名随机男性的病历进行了回顾性分析，共获得 140 项 TT、aFT 和 SHBG 完整的检测结果。通过在线计算器确定计算出的 FT。采用 Pearson 秩相关系数进行比较。
aFT 和 cFT 之间的 Pearson 秩相关系数。
患者平均年龄为 52.3 ± 14.3 岁（范围 24-80）。平均 TT 为 443.0 ± 208.3ng/dL（范围 110-1276）。平均 aFT 为 1.22 ± 0.54ng/dL（范围 0.24-3.8），平均 cFT 为 9.4 ± 4.5ng/dL（范围 1.8-27.8）。平均 SHBG 为 34.2 ± 19.5nmol/L（范围 9-127）。aFT 和 cFT 之间存在很强的相关性（r=0.88，P<0.0001），尤其是在低浓度时。aFT 与 TT 之间（r=0.73，P<0.0001）和 cFT 与 TT 之间（r=0.82，P<0.0001）也存在显著相关性。aFT 的数值约为 cFT 数值的八分之一。aFT 和 cFT 均与 SHBG 不相关。
在本临床门诊男性人群中，aFT 和 cFT 之间存在很强的相关性。这两种检测方法必须使用不同的参考值集。
