Testosterone Undecanoate Significantly Reduces Low Density Lipoprotein Cholesterol and Triglycerides in Men With Adult-Onset Testosterone Deficiency.

BACKGROUND: Adult-onset testosterone deficiency, a condition characterised by low serum testosterone and hypogonadal symptoms is associated with a higher incidence of cardiovascular disease (CVD) and mortality. OBJECTIVE: To evaluate associations between change (Δ) in total cholesterol (TC), triglycerides (TG) and low-density lipoprotein (LDL)-cholesterol and testosterone undecanoate (TU) treatment. MATERIALS & METHODS: We analysed a registry of men with adult-onset TD (409 TU-treated and 415 TU-untreated men, median follow-up 153 months), restricting the analysis to men whose statin treatment was not changed during follow-up, thus avoiding statin related effects. The study cohort comprised the following groups: TU-untreated/not on statins (n = 95), TU-untreated/on statins (n = 245), TU-treated/not on statins (n = 194), and TU-treated/on statins (n = 207). Intra-group non-parametric statistics were performed as baseline characteristics varied between the study groups. We used multivariate and logistic regression models to determine predictors of ∆ lipids (LDL-cholesterol and TG) and mortality. RESULTS: Whilst there was a significant decrease in LDL-cholesterol and TG (mostly in the initial 24 months) in the TU-treated men, the reverse was evident in the untreated men, irrespective of concurrent statin therapy. Baseline LDL-cholesterol and TG inversely predicted ∆ values in the TU-treated men, regardless of statin therapy. LDL-cholesterol at final assessment appeared independently associated with mortality. CONCLUSIONS: In this long-term, real-world registry, TC, TG, and LDL-cholesterol decreased in the TU-treated men with baseline values predicting the change, whilst a gradual increase was observed in the TU-untreated men. Using published data, the relative risk reduction in CVD due to LDL-cholesterol reduction is estimated to be around 40%.