Low serum testosterone, arterial stiffness and mortality in male haemodialysis patients

Background. In the general population, accumulating data support a link between low testosterone levels and mortality by all causes, but especially by cardiovascular disease (CVD). Also, accelerated arterial stiffness has been recognized as an important cardiovascular risk factor. Here, we explored the association between testosterone levels and risk of death in male haemodialysis (HD) patients, whose arterial system is characterized by generalized stiffening. Methods. In this three-centre prospective observational study, 111 male HD patients after completion of baseline assessment, including measurement of male sex hormones and pulse wave velocity (PWV), were followed up for CVD and all-cause mortality. Results. Of the 111 patients studied, 54 were found with and 57 without testosterone deficiency, defined as testosterone levels < 8 nmol/L. During a median follow-up period of 37 months, 49 deaths occurred, 28 (57%) of which were caused by CVD. Testosterone deficiency patients had increased CVD and all-cause mortality {crude hazard ratio: 3.14 [95% confidence interval (CI), 1.21-8.16] and 3.09 (95% CI, 1.53-6.25), respectively}, even after adjustment for age, body mass index, serum albumin and C-reactive protein, prevalent CVD and HD vintage. The association of testosterone with CVD mortality, but not with all-cause mortality, was lost after adjusting for PWV, an index of arterial stiffness. Testosterone levels were inversely related to PWV (r = -0.441; P < 0.001). Conclusion. We showed that testosterone deficiency in male HD patients is associated with increased CVD and all-cause mortality and that increased arterial stiffness may be a possible mechanism explaining this association.