Aiji Yajima¹, Andreas Pasch² and Kosaku Nitta³

¹Department of Nephrology, Towa Hospital, Tokyo, Japan. ²Department of Nephrology and Hypertension, Inselspital, University of Bern, Bern, Switzerland. ³Department of Medicine, Kidney Center, Tokyo Women’s Medical University, Tokyo, Japan.

Abstract

Treatment of secondary hyperparathyroidism in patients with chronic kidney disease (CKD) stage III and IV with vitamin D sterols is useful to maintain optimal parathyroid hormone (PTH) levels and thereby, reduces the severity of bone abnormalities caused by high PTH levels. However, it should be borne in mind that serum calcium (Ca) levels may easily increase as bone turnover is easily suppressed due to diffuse or early nodular parathyroid tissue in these patients. Furthermore, an elevated risk of cardiovascular disease due to advanced atherosclerosis associated with both secondary hyperparathyroidism and the administration of vitamin D sterols has been reported in patients with moderate to severe CKD, resulting in a high mortality in these patients. In order to control serum Ca levels, therefore, additional use of cinacalcet hydrochloride may be useful. However, acute reduction of serum Ca levels and chronic hyperphosphatemia should be avoided; therefore, the doses of phosphorus (P) binders should be increased or the initiation of low doses of vitamin D sterols may be favorable in patients with stage III and IV CKD receiving cinacalcet hydrochloride. The phosphaturic effect of FGF-23 after treatment with cinacalcet is estimated to be small as compared with that of vitamin D in moderate to severe CKD patients, therefore, evaluation of osteocytes should be performed in patients with secondary hyperparathyroidism treated with cinacalcet hydrochloride.