Phosphorus Absorption in Healthy Adults and in Patients With Moderate Chronic Kidney Disease

Chronic Kidney Disease Mineral and Bone Disorder Clinical Trial

Official title:

Phosphorus Absorption in Healthy Adults and in Patients With Moderate Chronic Kidney Disease

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT03108222
• Other study ID #: 1612460566
• Status: Active, not recruiting
• Start date: April 25, 2018
• Est. completion date: December 2019

Study information

• Verified date: July 2019
• Source: Purdue University
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

Chronic kidney disease (CKD) affects approximately 26 million Americans with many more at risk for disease development. Elevated serum phosphorus (P) and related abnormalities in P homeostasis due to progressive loss of kidney function are primary driving forces behind cardiovascular dysfunction and mortality in CKD patients. Intestinal P absorption is an critical aspect in P homeostasis but has been understudied, particularly in the early stages of CKD progression. This study aims to determine P absorption in patients with moderate CKD compared to healthy adults.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 20
• Est. completion date: December 2019
• Est. primary completion date: August 30, 2019
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 30 Years to 75 Years

Eligibility

Inclusion:

Men and women ages 30-75 years old, any race

Moderate CKD, based on the last set of labs done in the past year, defined as:

Glomerular Filtration Rate (GFR) category G3a (eGFR 45-59 mL/min) with A2 or A3 albuminuria or proteinuria by positive dipstick or urine protein/creatinine ratio (UPCR); -or- G3b (eGFR 30-44 mL/min), with or without evidence of albuminuria (any A1-A3) or proteinuria. (Figure 1)

-or- Healthy control with no diagnosis or evidence of CKD

Female subjects must be post-menopausal, surgically sterile, or confirmed not pregnant by pregnancy test and not breastfeeding.

Subjects must be on stable doses of medications (except those noted in exclusion criteria) for at least 6 weeks prior to the study

Exclusion:

Plans to initiate dialysis within 6 months

Labs based on the last set done in the past year:

Hypercalcemia defined as serum calcium > 10.5 mg/dL

Hyperkalemic > 5.5 mg/dL Prescribed a phosphate binder medication

Small bowel resection, bariatric surgery. Medically unstable or poorly controlled hypertension, diabetes, or gastrointestinal disorders in the opinion of the physicians on the study team

Calcitriol, ergocalciferol, cholecalciferol, vitamin D analogs, calcimimetics, PTH analogues, calcium supplements, multivitamins/mineral and other medications that may alter phosphorus metabolism - must be off for at least 6 weeks prior to study

Related Conditions & MeSH terms

• Bone Diseases
• Chronic Kidney Disease Mineral and Bone Disorder
• Chronic Kidney Disease-Mineral and Bone Disorder
• Kidney Diseases
• Renal Insufficiency, Chronic

Intervention

Other:
• Phosphorus Absorption Test
Subjects will undergo a radiophosphorus (P-33) absorption test over two days, that will include an oral administration of P-33 on the 1st day of the test, and an IV administration of P-33 on the 2nd day of the test. P-33 activity from serial serum and urine collections will be determined by scintillation counting, and fractional phosphorus absorption calculated by kinetic modeling.

Locations

Country	Name	City	State
United States	Purdue University Nutrition Science Department	West Lafayette	Indiana

Sponsors (1)

Lead Sponsor	Collaborator
Purdue University

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Fractional Phosphorus Absorption	Radiophosphorus (P-33) activity determined by liquid scintillation counting in serum and urine after oral and IV administration will be used to determine fractional phosphate absorption.	Measured from serial blood draws over a 4-hour time frame
Secondary	Serum FGF23	serum intact and c-terminal FGF23	Measured from baseline measures and serial blood draws over a 4-hour time frame
Secondary	Serum 1,25(OH)2D	serum 1,25-dihydroxyvitamin D	Measured from baseline measures and serial blood draws over a 4-hour time frame
Secondary	Serum parathyroid hormone (PTH)	serum intact parathyroid hormone	Measured from baseline measures and serial blood draws over a 4-hour time frame
Secondary	Serum phosphate	serum phosphate	Measured from baseline measures and serial blood draws over a 4-hour time frame
Secondary	24h Urine phosphate	24h urine phosphate	measured from two, 24-hour urine collections