The association between age and mortality in men with adult-onset testosterone deficiency is altered by testosterone...

Using the Gompertz-Makeham model, we describe associations between age and the probability of mortality in men with adult-onset testosterone deficiency (TD), stratified by testosterone undecanoate (TU) treatment and type 2 diabetes (T2DM).

We analyzed a registry of 737 men (353 and 384 men on/not on TU, respectively) with adult-onset TD with nearly 9 years of follow-up. We compared associations between age and mortality using nonparametric and logistic regression models (estimating individual mortality probability) in men stratified by TU treatment and T2DM.

Mortality was lower (p < 0.001) in men on TU compared to men opting against TU. In the men on TU, age was associated with mortality (odds ratio (OR): 1.26, 95% confidence interval (CI): 1.13-1.40) in the nonlinear pattern expected in the Gompertz‒Makeham model. However, age was not associated with mortality in men not on TU (OR: 1.03, 95% CI: 0.98-1.08). T2DM status did not affect these associations.

The association between age and mortality differed between men on TU and those opting against treatment. In untreated men, features of metabolic syndrome worsened, which perhaps minimized the relationship between age and mortality. In men on TU, these metabolic risk factors improved, perhaps restoring the association between age and mortality.