Clinical trial NCT00297219: Effects of Lowering Dialysate Calcium Level on Progression of Coronary Artery Calcification and Bone Histomorphometry
Official title: The Effects of Lowering Dialysate Calcium Level on Progression of Coronary Artery Calcification and Bone Histomorphometry: Prospective, Randomized, Controlled Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: End-Stage Renal Disease
Hemodialysis
Keywords: Hemodialysis
Coronary artery calcification
Adynamic bone disease
Dialysate calcium
Bone mineral density
Bone histomorphometry
Lead sponsor: Ege University
Sponsor class: OTHER
Collaborators: name: University of Kentucky
name: Fresenius Medical Care North America
First posted: 2006-02-28
Enrollment: 457
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The high rate of cardiovascular complications in the dialysis population cannot be explained by traditional cardiovascular risk factors. One of such factors proposed to contribute to the cardiovascular mortality in dialysis patient population is vascular calcification possibly resulting from disturbances of calcium-phosphate metabolism.

The aim of this study is to assess the effects of treatment with dialysate containing 1.75 or 1.5 mmol/L to 1.25 mmol/L calcium regarding coronary artery calcification and bone histomorphometry in hemodialysis patients.

Detailed description: Sample size calculations were based on previously reported changes in coronary artery calcification scores in hemodialysis patients during time (90% power with a two-sided, alpha error rate of 5%). Four hundred fifty-seven hemodialysis patients, taking drop-out rate into consideration, will be enrolled in this prospective-controlled study.The cases already being treated with calcium-based phosphate binder and dialysate containing 1.75 or 1.5 mmol/L calcium will be enrolled from eight hemodialysis centers.The cases will be randomized to two arms:

1. Dialysate containing 1.25 mmol/L calcium + calcium-based phosphate binder group: Dialysate calcium will be reduced from 1.75 or 1.5 mmol/L to 1.25 mmol/L in this group. Patients will use calcium-based phosphate binder according to phosphate level.
2. Dialysate containing 1.75 mmol/L calcium + calcium-based phosphate binder group (Control group): Dialysate calcium will remain or switched to 1.75 mmol/L and patients will be on calcium-based phosphate binder.

The study will last for 18 months.Coronary artery calcification (Multi-slice CT), bone histomorphometry, and bone mineral density will be assessed in the beginning and at the end of the study. Coronary artery calcification and bone mineral density will be measured in all patients; bone histomorphometry will be assessed in 150 patients, 75 from each group.

Eligibility criteria: Inclusion Criteria:

* Aged between 18 and 80 years
* On maintenance bicarbonate hemodialysis scheduled thrice weekly, at least 12 hours/week
* To be treated with a dialysate containing 1.75 or 1.5 mmol/L calcium
* Willingness to participate in the study with a written informed consent

Exclusion Criteria:

* To be scheduled for living donor renal transplantation
* To have serious life-limiting co-morbid situations, namely active malignancy, active infection, end-stage cardiac, pulmonary, or hepatic disease
* Pregnancy or lactating
* To be unable to give informed consent because of mental incompetence or a psychiatric disorder
* To be on vitamin D treatment within six months of randomization or having iPTH values over target levels (\>300 pg/mL)
* Hypercalcemia (Ca \>10.5 mg/dl) with use of dialysate containing 1.75 or 1.5 mmol/L calcium

Primary outcomes:
measure: Progression of coronary artery calcification scores
timeFrame: eighteen months
measure: Changes in bone histomorphometry analysis
timeFrame: eighteen months
measure: Changes in bone mineral density
timeFrame: eighteen months
Secondary outcomes:
measure: Changes in intact PTH levels
timeFrame: eighteen months
measure: effects of dialysate with or without glucose (e.g intradialytic hypoglycemia and hypotension, arrythmia-by Holter ECG- and changes in HbA1c, insulin)
timeFrame: eighteen months
Other outcomes:
Locations:
city: Lexington
country: United States
facility: University of Kentucky Medical Center
state: Kentucky
city: Bornova
country: Turkey
facility: FMC Clinics
state: Izmir
city: Bornova-Izmir
country: Turkey
facility: Ege University School of Medicine
Study officials:
affiliation: Ege University School of Medicine Nephrology Department
name: Ercan Ok, MD
role: PRINCIPAL_INVESTIGATOR
References: