Association of FGF-23 and Parathyroid Hormone (PTH) in Dialysis Patients
Association of FGF-23 and Parathyroid Hormone (PTH) in Dialysis Patients
The purpose of this study is to determine how levels of this newly-discovered hormone, called
 FGF-23, changes in the blood in response to a high calcium dialysis bath during a
 hemodialysis (HD) treatment, and how this relates to changes in the calcium and PTH levels.
 We are also studying the effects of dialysis and inflammation on the levels of Fetuin A.

 We intend to prospectively study a cohort of end stage renal disease (ESRD) patients on
 hemodialysis in order to determine whether FDF-23 levels independently affect
 non-suppressible PTH levels. The relationship between Fetuin A and inflammatory markers will
 also be determined. By dialyzing patients on 3.5 mEq/L calcium dialysate bath, we seek any
 relationship between ionized calcium, FGF-23 and PTH.
The goal of this study is to ascertain whether there is a regulatory relationship between the
 novel phosphorus-regulating polypeptide fibroblast growth factor-23 (FGF-23), ionized calcium
 (iCa), and parathyroid hormone (PTH) levels. In addition, we will determine if there is an
 inverse relationship between Fetuin A levels and inflammatory markers, interleukin 6 (IL-6)
 and C-reactive protein (CRP), during a hemodialysis treatment.

 All patients participating in this study will be off Zemplar and/or Sensipar for a washout
 period of approximately 4 weeks as these medications will interfere with the study. Patients
 will go through one designated research hemodialysis time for a blood draw. Blood draws will
 be taken during 4 separate intervals at 0, 45, 90 and 150 minutes. At each interval, 4 tubes
 of blood will be drawn.

 There are no further required blood draws once each designated research HD session has been
 completed. At the conclusion of the designated research HD session, vitamin D analogue
 (Zemplar®) and/or Cinacalcet (Sensipar®) will be restarted, and the dose will be adjusted to
 reflect the subject's recent biochemical markers (Ca, Phos, and iPTH).
Inclusion Criteria:

 -  18 years or older

 -  Chronic Hemodialysis for more than 3 months

 -  iPTH levels ≥ 300 pg/ml in the absence of therapy: Cinacalcet (Sensipar ®) and/or 1,25
 Vitamin analogues (Zemplar®)

 -  Corrected Ca ≥ 8.4 mg/dl at time of enrollment

 -  Ability to stay at least 3 hours during hemodialysis treatment

 Exclusion Criteria:

 -  Pediatric Patients (age ≤ 18 years)

 -  Those unable to give informed consent

 -  Dialysis treatment for less than 3 months, or pre-emptive kidney transplantation

 -  Inability to stay more than 3 hours during a single hemodialysis treatment period