Statin, testosterone and phosphodiesterase 5-inhibitor treatments and age related mortality in diabetes

AIM To determine how statins, testosterone (T) replacement therapy (TRT) and phosphodiesterase 5-inhibitors (PDE5I) influence age related mortality in diabetic men. METHODS We studied 857 diabetic men screened for the BLAST study, stratifying them (mean follow-up = 3.8 years) into: (1) Normal T levels/untreated (total T > 12 nmol/L and free T > 0.25 nmol/L), Low T/untreated and Low T/treated; (2) PDE5I/untreated and PDE5I/treated; and (3) statin/untreated and statin/treated groups. The relationship between age and mortality, alone and with T/TRT, statin and PDE5I treatment was studied using logistic regression. Mortality probability and 95% CI were calculated from the above models for each individual. RESULTS Age was associated with mortality (logistic regression, OR = 1.10, 95% CI: 1.08-1.13, P < 0.001). With all factors included, age (OR = 1.08, 95% CI: 1.06-1.11, P < 0.001), Low T/treated (OR = 0.38, 95% CI: 0.15-0.92, P = 0.033), PDE5I/treated (OR = 0.17, 95% CI: 0.053-0.56, P = 0.004) and statin/treated (OR = 0.59, 95% CI: 0.36-0.97, P = 0.038) were associated with lower mortality. Age related mortality was as described by Gompertz, r(2) = 0.881 when Ln (mortality) was plotted against age. The probability of mortality and 95% CI (from logistic regression) of individuals, treated/untreated with the drugs, alone and in combination was plotted against age. Overlap of 95% CI lines was evident with statins and TRT. No overlap was evident with PDE5I alone and with statins and TRT, this suggesting a change in the relationship between age and mortality. CONCLUSION We show that statins, PDE5I and TRT reduce mortality in diabetes. PDE5I, alone and with the other treatments significantly alter age related mortality in diabetic men.