The Effects of Dietary Phosphate Intake on Calciotropic Hormones and FGF23.

Healthy Clinical Trial

Official title:

The Effects of Dietary Phosphate Intake on Calciotropic Hormones and FGF23

Clinical Trial Details — Status: Withdrawn

Administrative data

• NCT number: NCT00305279
• Other study ID #: H40550-27771
• Secondary ID: 1K23RR020343
• Status: Withdrawn
• Phase: N/A
• First received: March 17, 2006
• Last updated: October 9, 2013
• Start date: February 2006
• Est. completion date: December 2009

Study information

• Verified date: October 2013
• Source: University of California, San Francisco
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review BoardUnited States: National Institutes of Health
• Study type: Interventional

Clinical Trial Summary

The purpose of this study is to determine the effects of different amounts of phosphorus in the diet on hormones that control phosphorus and bone health both in people who are healthy and in ones who have moderate kidney disease.

Description:

Chronic kidney disease affects 11% of the US population; over half of those affected have skeletal manifestations of their renal disease. Renal osteodystrophy is a complex disease, in which multiple mineral systems and related hormones play a role, including phosphate homeostasis. Phosphate regulation primarily depends on renal handling of phosphate, which is partly controlled by parathyroid hormone and vitamin D. However, other mediators in this system clearly exist. Recently, evidence has been accruing that one such factor may be FGF23, a protein produced by osteogenic cells. States of excess FGF23 are associated with marked phosphate wasting, hypophosphatemia, osteomalacia, and inappropriately low calcitriol. FGF23 levels are measurable in healthy humans and markedly elevated in patients who require hemodialysis, although its physiologic role in either state is unknown. Some retrospective evidence suggests that FGF23 is affected by phosphate intake. We are performing a study to gather data describing the response of FGF23 to changes in dietary phosphorus intake in healthy men and women and in men and women with moderate renal insufficiency. The specific aims of this pilot study are: 1) To examine the physiologic effects of alterations in dietary phosphorus on FGF23 in healthy subjects; 2) To examine the physiologic response of FGF23 to dietary phosphorus alterations in patients with moderate renal failure; and 3) To assess whether serum levels of 1,25-dihydroxyvitamin D vary inversely with those of FGF23 when dietary phosphate is changed. The proposed research plan is a dietary intervention trial in which we will study the response of serum FGF23 levels to diets with varying phosphorus contents in healthy adults and adults with moderate renal insufficiency.

Recruitment information / eligibility

• Status: Withdrawn
• Enrollment: 0
• Est. completion date: December 2009
• Est. primary completion date: December 2009
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 21 Years to 65 Years

Eligibility

Inclusion Criteria:

HEALTHY SUBJECTS:

• Men 21-65 years of age;

• Premenopausal women over 21 years of age taking oral contraceptives;

• Postmenopausal women less than 65 years of age;

CHRONIC KIDNEY DISEASE SUBJECTS:

• Men 21-65 years of age;

• Premenopausal women over 21 years of age taking oral contraceptives;

• Postmenopausal women less than 65 years of age;

• Creatinine clearance between 30 and 59 ml/min/1.73 m2 as calculated using the equation derived from the Modification of Diet in Renal Disease (MDRD) study.

Exclusion Criteria:

• Medications affecting bone metabolism;

• Abnormal liver or GI function;

• Extreme electrolyte abnormalities;

• BMI >30 kg/m2.

Study Design

Allocation: Randomized, Intervention Model: Crossover Assignment, Masking: Single Blind (Subject)

Related Conditions & MeSH terms

• Healthy
• Kidney Failure, Chronic
• Renal Insufficiency

Intervention

Other:
• Dietary
Dietary
• Dietary
Dietary
• Dietary
Dietary

Locations

Country	Name	City	State
United States	University of California	San Francisco	California

Sponsors (2)

Lead Sponsor	Collaborator
University of California, San Francisco	National Institutes of Health (NIH)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Hormonal regulators of mineral metabolism		Last two days of each intervention phase	No