Table 5.

Influence of Age on Free Testosterone Levels in Community Men

Age (years)20-2930-3940-4950-5960-6970-79>80
Mean (pg/ml)14813211699827258
5th Percentile79706150453329
95th Percentile22921219916413513293
n22066087278849328926

Total testosterone was measured in community dwelling men in Framingham, MA using LC-MS. SHBG was measured using a two-site immunofluorometric assay from DELFIA-Wallac, Inc. Free testosterone was calculated by the law-of-mass-action equation using of K SHBG-T of 0.998 × 109 L/mol and a K Alb-T of 3.57 × 104 L/mol. Data from Bhasin et al (29). To convert total testosterone levels to nmol/L multiply by 0.0347.

From: Laboratory Assessment of Testicular Function

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