Assessment and Diagnosis
Figure 1. An approach for the diagnostic evaluation of adult men suspected of having androgen deficiency
History and physical (symptoms and signs)
Morning Total T Low Ta
Exclude reversible illness, drugs, nutritional deficiency Repeat T [use free or bio T, if altered SHBGb LH & FSH
] SFA [if fertility issue] Confirmed low Ta or free or bio T < normalc
Low T, low or normal LH+FSH (2º)
Consider: Prolactin, iron, other pituitary hormones, MRI [under certain circumstancesd
] high LH+FSH (1º) Low T,
Normal T, LH+FSH
Consider karyotype for Klinefelter syndrome (elevated LH and FSH, low or low normal serum T, very small testes, azoospermia, gynecomastia, and learning disorder)
T, Testosterone; bio T, bioavailable T; SFA, seminal fluid analysis; 1º, primary hypogonadism; 2º, secondary hypogonadism
a
In some laboratories, the lower limit of the normal testosterone range in healthy young men is approximately 300 ng/dL (10.4 nmol/L). However, this range may vary in different laboratories. Use the lower limit of the range established in your reference laboratory.
b Refer to Table 5 for a list of conditions that alter SHBG concentrations. c
In some reference laboratories, the lower limit of the normal free testosterone range in healthy young men is approximately 5 ng/dL (0.17 nmol/L) (approximate lower limit of normal in three major commercial laboratories) using equilibrium dialysis or calculated from total testosterone and SHBG. However, this range may vary in different laboratories [approximate lower limits of normal ranging from 4 to 9 ng/dL (0.14 to 0.31 nmol/L) in major commercial laboratories) using equilibrium dialysis or calculated from total testosterone and SHBG and the reference population used. Use the lower limit of the range established in your reference laboratory.
d
Perform pituitary imaging (MRI) to exclude pituitary and/or hypothalamic tumor or infiltrative disease, if severe secondary hypogonadism (serum T < 150 ng/dL), panhypopituitarism, persistent hyperprolactinemia, or symptoms or signs of tumor mass effect, such as headache, visual impairment, or visual field defect, are present.
2 Normal T Follow up
