Absence of a therapeutic effect of zinc in the sexual dysfunction of haemodialysed patients

The effect of zinc therapy and placebo on sexual function and endocrine status was investigated in a double-blind study of 14 male patients with chronic renal failure on regular haemodialysis. Zinc chloride was added to the dialysate of 7 patients for 6 weeks, raising the serum zinc concentration by 17% and placebo was added to the dialysate of the other patients. At the start of the trial 9 patients said they had decreased sexual function. Records of penile erectile activity during sleep confirmed the organic nature of the sexual dysfunction. Plasma testosterone concentrations were low or in the low normal range, basal serum luteinising-hormone levels were raised, and the early luteinising-hormone response to luteinising-hormone-releasing hormone was exaggerated, suggesting primary testicular failure. Zinc administration had no significant effect on any aspect of sexual function assessed by questionnaire or nocturnal penile tumescence monitoring. Plasma testosterone and basal and stimulated gonadotrophin levels were also unaltered by zinc administration.