Reference intervals for serum testosterone, SHBG, LH and FSH in males from the NORIP project

Abstract

Reference intervals were calculated for male testosterone, SHBG, FSH and LH in serum from 599 individuals in the NORIP study. At 30 years of age, reference limits were calculated to 10.4–32.6 nmol/L testosterone, 13.5–57.4 nmol/L SHBG, 1.93–9.7 IU/L LH and 1.5–10.3 IU/L FSH, at 50 years, 9.3–31.3 nmol/L (testosterone), 18.4–75.6 nmol/L (SHBG), 2.01–10.4 IU/L (LH) and 2.04–12.4 IU/L (FSH), and at 70 years 8.6 to 30.7 nmol/L (testosterone), 27.8–101 nmol/L (SHBG), 2.22–11.2 IU/L (LH) and 2.71–14.2 IU/L (FSH). All age-+related changes were statistically significant. Reference intervals were also calculated for indices derived from testosterone, SHBG and albumin. Free androgen index, simply the ratio between testosterone and SHBG, returned results differing from the other elaborate indices, and the study thus favors use of a more elaborate index such as calculated free testosterone (CFT).

Key Words::

• Fertility hormones
• hormones
• reference levels
• endocrinology

Acknowledgements

We thank Astrid Steiro and Hildur Tannum, Rikshospitalet for skillful technical assistance, Pål Rustad, Dr Fürst Medical Laboratory for assisting on NOBIDA data, the personnel of the NOBIDA biobank for friendly cooperation and Kjell–Torgeir Stokke and Thor Hilberg, Dr Fürst Medical Laboratory, for suggestions.

Half the cost of reagents in the study was discounted by Roche Diagnostics, Norway.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.