Treatment of persistent hyperparathyroidism in renal transplant patients with cinacalcet improves control of blood pressure

Abstract

Persistent hyperparathyroidism is observed in 17% to 50% of patients at 1 year after renal transplantation. In 10% of these patients, hypercalcemia is also present. This condition increases the risk of vascular calcification, correlating with inferior graft function among patients with interstitial calcification in the renal allograft. Hypertension is appears in 60% to 90% of patients after transplantation, favoring progressive graft dysfunction. Hypercalcemia per se causes hypertension. Parathyroid hormone can potentiate the pressor effects of hypercalcemia. Fourteen renal transplant recipients were included based upon: total serum calcium > 10.0 mg/dL, intact parathyroid hormone levels > 70 pg/mL, graft function > 6 months, creatinine clearance > 50 mL/min, and stable immunosuppressive therapy. We also examined blood pressure and antihypertensive treatment. Initially patients received 30 mg of cinacalcet once a day. The follow-up was up to 6 months. The mean cinacalcet dose was 40 mg/24 h. Five patients received 60 mg/24 h. Both serum calcium and iPTH decreased significantly from 10.6 (DE 0.4) to 9.8 (DE Both serum calcium and iPTH decreased significantly from 10.6 (DE 0.4)to 9.8 (DE 0.6) mg/dL (P < .001) and from 195.0 (DE 140.0) to 118.62 (DE 102.2; P < .0001). There were no significant changes in renal function, proteinuria, or tacrolimus levels. Mean blood pressure diminished from 94.1 (DE 12.0) to 88.0 (DE 7.5) mm Hg (P < .019) with no changes in antihypertensive treatment. Cinacalcet was suspended in one patient because of gastrointestinal discomfort and in another one because the iPTH was reduced to 51 pg/mL. Cinacalcet is an effective treatment for persistent hyperparathyroidism associated with hypercalcemia among renal transplant patients and may be helpful for hypertension control.