Background: Testosterone replacement is the mainstay of treatment for male hypogonadism. The most commonly reported adverse event in testosterone trials is polycythaemia. This study assessed the prevalence of polycythaemia in males receiving testosterone replacement and compared prevalence rates between different treatment preparations.
Methods: 216 men were included in this retrospective observational study conducted from January 2009 to December 2012. 155 (72%) were treated with i.m. testosterone in the form of testosterone undecanoate (Nebido) or Sustanon. The remaining 61 (28%) men were treated with transdermal testosterone gel. Data were collected on haemoglobin concentrations, packed cell volumes, gonadotrophins, total serum testosterone concentrations and prostate-specific antigen (PSA) levels. Polycythaemia was defined as at least one haemoglobin concentration ≥17 g/dl or packed cell volume ≥0.505. A raised PSA was defined as >4.4 μg/l.
Results: Overall, 38 men (17.6%) developed polycythaemia on at least one blood sample during the follow-up period. The rate of polycythaemia was higher in the i.m. treatment group (19.4%) than the transdermal group (13.1%), as was peak haemoglobin concentration (15.58 vs 15.00 g/dl) though only the later was statistically significant (P<0.05). Overall there was a positive correlation between peak haemoglobin concentration and mean total testosterone level (r(214)=0.138, P<0.05). No relationship was found between PSA and mode of treatment or total testosterone concentration. Contrary to other studies, no association was found between development of polycythaemia and older age.
Conclusion: Polycythaemia is common in men receiving testosterone therapy, regardless of treatment modality. This risk should be weighed against the potential benefits prior to initiating therapy. Men receiving testosterone treatment should have their haematological variables monitored regularly and testosterone dose adjusted accordingly.