Effect of Calcium Channel Blocker on the Serum Fibrobalst Growth Factor-23 (FGF-23) Levels in Type-2 Diabetic Patients With Proteinuria Purpose

November 29, 2012 updated by: Mahmut Ilker Yilmaz, Gulhane School of Medicine

In recent years, diabetic nephropathy, which may lead to dialysis treatment, is the most prevalent underlying disease of people in developed countries. A wide range of studies have been carried out, from various points of view, to understand the progress of renal dysfunction in diabetic nephropathy.

Fibroblast growth factor 23 (FGF-23) is a primary regulator of renal phosphate excretion. FGF23 is inversely associated with the GFR, a relationship underlying a fundamental mechanism for maintaining serum phosphate constancy during CKD progression. Such an adaptation may have deleterious trade-offs because, independently of serum phosphate, high FGF23 signals a high risk of death in ESRD patients. Some studies showed that there is relationship between FGF-23 levels and proteinuria in CKD patients.

There is no data about the effects of calcium channel blocker on FGF23 levels in diabetic patients with proteinuria. The aim of this study was to find out whether the beneficial effects of calcium channel blocker in diabetic proteinuria has any relation with the alteration of FGF-23 levels. The investigators searched for the effects of calcium channel blocker amlodipine on the clinical and laboratory parameters of diabetic patients with proteinuria.

The investigators registered the study 'The effect of renin angiotensin system Blockage (RAS), calcium channel blocker and combined drugs on TWEAK, PTX3 and FMD levels in Diabetic Proteinuric Patients with Hypertension' (ClinicalTrials.gov Identifier:NCT00921570). The investigators will use the samples of the some patients for this study. The investigators also registered the study 'FGF-23 and Endothelial Dysfunction in Diabetic Proteinuric Patients' (ClinicalTrials.gov Identifier: NCT01703234). The investigators will combine these two registered studies (NCT00921570 and NCT01703234) in one study.

Study Overview

Detailed Description

The patients who were non-obese (BMI<30kg/m2), non dyslipidemic (total cholesterol <200mg/dl, Triglyceride<150mg/dl), and free of cardiovascular events (negative medical history, negative ECG findings) were investigated for enrollment. CKD stage 1 patients older than 18 years of age and willing to participate to the study were screened. From the 231 patients with established type 2 diabetes mellitus, 126 had proteinuria and/or hypertension (24 h protein excretion 1-2 g/day, systolic blood pressures ≥140mmHg and/or diastolic blood pressures ≥ 90 mmHg, respectively). All cases were first referrals and at the time of the study all were off treatment. Patients with history of coronary artery disease, smokers and those taking statins or renin-angiotensin blockers were excluded because of the effect of these factors on endothelial dysfunction. Of 61 screened patients 32 met the study criteria and were included in this study. The duration of proteinuria and diabetic nephropathy after initial diagnosis was not known.

The exclusion criteria were as follows: A)Nephrotic syndrome, B)coronary heart disease (patients with ischemic ST-T alterations and voltage criteria for LVH on electrocardiogram, and with history of revascularization or myocardial infarction), C) elevated liver enzymes (AST or ALT levels ≥ 40U/L) and D) renal failure (serum creatinine levels > 1.3 mg/dl). In order to evaluate the effect of calcium channel blocker on serum FGF-23 concentrations, patients with proteinuria were given an calcium channel blocker (Amlodipine 10 mg/day) for 12 weeks. The effect of calcium channel blocker on insulin sensitivity and proteinuria was also investigated.

After the intervention period, blood samples were obtained for assay of plasma PTX3 concentrations, HbA1c , and insulin resistance scores (HOMA-IR).

Urine samples were also collected over a 24-hour period to determine the degree of proteinuria.

Study Type

Interventional

Enrollment (Actual)

32

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Ankara, Turkey, 06018
        • Gulhane School of Medicine

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • CKD stage 1 patients
  • Older than 18 years of age
  • Type 2 Diabetic patients
  • Proteinuria

Exclusion Criteria:

  • History of coronary artery disease
  • Smokers
  • Taking statins or renin-angiotensin blockers

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Amlodipine
Amlodipine 10 mg/day for 12 weeks
10 mg/day for 12 weeks

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Fibroblast Growth factor 23

Secondary Outcome Measures

Outcome Measure
Flow mediated dilatation

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 1, 2008

Primary Completion (Actual)

May 1, 2009

Study Completion (Actual)

May 1, 2009

Study Registration Dates

First Submitted

November 28, 2012

First Submitted That Met QC Criteria

November 29, 2012

First Posted (Estimate)

November 30, 2012

Study Record Updates

Last Update Posted (Estimate)

November 30, 2012

Last Update Submitted That Met QC Criteria

November 29, 2012

Last Verified

February 1, 2008

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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