Very low endogenous testosterone in men is associated with high risk of ischaemic stroke

A study of a Danish population has found that low testosterone is associated with increased risk of ischaemic stroke in men, but not in women. Levels of endogenous sex hormones were measured in 4,615 men and 4,724 women between 1981 and 1983. With up to 29 years of follow-up, 524 men and 563 women developed ischaemic stroke. No association was observed between the incidence of ischaemic stroke and levels of plasma oestradiol in either sex, or testosterone in women. However, the risk of ischaemic stroke was higher in men with testosterone concentrations up to the 10^th percentile, compared with the 11^th to 90^th percentiles (HR 1.34). Partial mediation of this increased risk meant that the corresponding hazard ratio was 1.46 in men with hypertension and overweight or obesity.