Dialysate calcium concentration during calcimimetic treatment: a neglected issue

Hypocalcaemia is a well-known effect of the treatment of secondary hyperparathyroidism when using calcimimetics. In a retrospective, observational, study, which was published recently in this Journal [1], Louie et al. investigated the frequency, predictors, and consequences of cinacalcetinduced hypocalcaemia in a cohort of over one thousand haemodialysis patients. They found that hypocalcaemia occurred in more than two third of the treated patients and was mild in many cases. Nonetheless, in one third it was moderate (1.87– < 2.0 mmol/L; 23%) or even severe (< 1.87 mmol/L; 9%). These results coming from a “realworld” setting raise questions on the true potentially negative impact of hypocalcaemia per se or of its treatment, including the increase of dialysate calcium concentration.