Testosterone and dihydrotestosterone and incident ischaemic stroke in men in the Cardiovascular Health Study

ObjectiveIschaemic stroke is a major cause of morbidity and mortality in elderly men. Our main objective was to examine whether testosterone (T) or dihydrotestosterone (DHT) was associated with incident ischaemic stroke in elderly men. DesignCohort study. ParticipantsElderly men in the Cardiovascular Health Study who had no history of stroke, heart disease or prostate cancer as of 1994 and were followed until December 2010. MeasurementsAdjudicated ischaemic stroke. ResultsAmong 1032 men (mean age 76, range 66-97), followed for a median of 10years, 114 had an incident ischaemic stroke. Total T and free T were not significantly associated with stroke risk, while DHT had a nonlinear association with incident stroke (P=0006) in analyses adjusted for stroke risk factors. The lowest risk of stroke was at DHT levels of 50-75ng/dl, with greater risk of stroke at DHT levels above 75ng/dl or below 50ng/dl. Results were unchanged when SHBG was added to the model. Calculated free DHT had an inverse linear association with incident ischaemic stroke with HR 077 (95% CI, 061, 098) per standard deviation in analyses adjusted for stroke risk factors. ConclusionsDihydrotestosterone had a nonlinear association with stroke risk in which there was an optimal DHT level associated with the lowest stroke risk. Further studies are needed to confirm these results and to clarify whether there is an optimal androgen range associated with the least risk of adverse outcomes in elderly men.