SP661
SERUM TOTAL AND FREE TESTOSTERONE CONCENTRATION IN MALE HEMODIALYSED PATIENTS WITH CHRONIC KIDNEY DISEASE AND SECONDARY HYPERPARATHYROIDISM TREATED WITH CINACALCET

Introduction and Aims: Calcium receptor (CaR) is expressed, among others in testis. Cinacalcet binds to the CaR, increases sensitivity of CaR to serum calcium and therefore is used in the treatment of secondary hyperparathyroidism (sHPT) in hemodialysed patients with chronic kidney disease (HDP). In most of male HDP, serum testosterone concentrations are lower than in healthy males. The aim of this study was to assess the influence of six-month treatment with cinacalcet on serum total and free testosterone concentration in male HDP with sHPT.

Methods: In 38 male HDP, with sHPT (PTH>300 pg/ml), serum PTH, total testosterone (TT), free testosterone (FT) were assessed before the first dose of cinacalcet and after 3 and 6 months of treatment

Results: In patients who completed the study cinacalcet treatment caused significant decrease of serum PTH from 1143 (828-1458pg/ml) at the baseline, to 809pg/ml (487-1132pg/ml) after 3 month of treatment (p=0.002), and to 607pg/ml (281-934pg/ml; p<0.0001) after 6 months of treatment. Serum TT concentration decreased from 4.95ng/ml (4.23-5.67)ng/ml to 4.45ng/ml (3.85-5.06)ng/ml; and to 4.39pg/ml (3.75-5.03)pg/ml, respectively (p for trend=0.009). Moreover, serum FT concentration decreased from 6.95pg/ml (5.54-8.36)pg/ml to 5.98pg/ml (5.00-6.94)pg/ml; p=0.14 and to 5.60pg/ml (4.63-6.57)pg/ml; p=0.034, respectively (p for trend=0.012).

In the multiple regression analyses the change of serum TT after 3 months of treatment was explained by the change of the serum PTH concentration. The change of serum TT after 6 months of treatment was explained by the dose of cinacalcet

Conclusions: Treatment with cinacalcet decreases serum total and free testosterone concentration in male hemodialysed patients with chronic kidney disease and secondary hyperparathyroidism.