Criteria - all of the following:
(1) late-onset
(2) symptomatic
(3) low serum testosterone
The meaning of late-onset was not defined. Subjects were >= 40 years of age with a mean age of 60 years. It is assumed that the person was "normal" prior to onset.
A patient was symptomatic if the patient had all 3 sexual symptoms associated with hypogonadism:
(1) decreased frequency of sexual thoughts (presumably with some loss of interest)
(2) decreased frequency of morning erections
(3) erectile dysfunction
A low serum testosterone was defined as both:
(1) a total serum testosterone concentration < 11 nmol/L (or < 3.2 ng/mL)
(2) a calculated free testosterone concentration < 220 pmol/L (< 64 pg/mL), using the formula of Vermeulen et al
Considering the availability of reliable methods of directly measuring free testosterone, the problems with calculated estimates for free testosterone, and the problems of interpreting the total serum testosterone level, the implementation will just use a directly-measured free testosterone < 220 pmol/L.
