Clinical trial NCT00477516: Association of FGF-23 and Parathyroid Hormone (PTH) in Dialysis Patients
Official title: Determination of FDF-23 Levels in Non-suppressible PTH Secretion and the Influence of Inflammation on Fetuin A Levels During Hemodialysis Treatment
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: End-Stage Renal Disease
Lead sponsor: University of Kansas Medical Center
Sponsor class: OTHER
First posted: 2007-05-23
Enrollment: 18
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: 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.

Detailed description: 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).

Eligibility criteria: 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

Primary outcomes:
measure: change in serum fibroblast growth factor-23 (FGF-23)
timeFrame: 0, 45, 90, and 150 minutes
Secondary outcomes:
Other outcomes:
Locations:
city: Kansas City
country: United States
facility: University of Kansas Medical Center
state: Kansas
Study officials:
affiliation: University of Kansas Medical Center
name: Peter W. Santos, D.O
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Kansas Medical Center
name: James B. Wetmore, M.D.
role: PRINCIPAL_INVESTIGATOR
References: