Endogenous testosterone to prostate-specific antigen relationship in men without prostatic diseases: a 10-year retrospective study

Background: The relationship between endogenous testosterone and PSA in men without prostatic diseases is controversial. Hence, this study was designed to investigate this relationship among healthy Nigerian men.Methods: A retrospective study of serum total testosterone (TT) and total PSA records of 1066 prostate disease-free men was undertaken in a Nigerian tertiary Hospital. Data on age, serum testosterone, and PSA from 1st January 2007 to December 2016 was abstracted and analysed.Results: The mean age, serum PSA, and serum total testosterone levels among study cohorts are 58.40±12.24 years, 3.0±2.24 µg/l, and 15.5±0.53 nmol/l respectively. There was an inverse relationship between serum PSA and testosterone levels with age. Subjects with high-risk PSA level (PSA>4.0 µg/l) had statistically significant higher PSA (p<0.001) and TT (p<0.001) values compared to the low-risk PSA level group. Subjects in the eugonadism group had higher PSA levels than those in the hypogonadism group (eugonadism 3.90µg/l±2.22 versus hypogonadism 2.18µg/l±2.30; p=0.012). Age correlated positively with PSA (p<0.001), but negatively with TT (p<0.001) while PSA correlated positively with TT (p<0.001).Conclusions: The findings of this study suggest an association between endogenous TT and PSA among healthy men without prostatic diseases and augment the evidence that serum TT maybe linked to prostate diseases. Clinical decisions regarding PSA should factor the levels of endogenous TT to enhance clinical judgments.