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

NCT03108222 | Unknown DMC

• 1 other identifier: 1612460566
• Study Type: observational
• Target: 20
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

Chronic Kidney Disease Mineral and Bone Disorder

Keywords

chronic kidney disease; CKD; renal failure; phosphorus; phosphate; intestinal absorption

Outcome Measures

Primary Outcomes (1)

• 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 Outcomes (5)

• Serum FGF23

  Measured from baseline measures and serial blood draws over a 4-hour time frame

• Serum 1,25(OH)2D

  Measured from baseline measures and serial blood draws over a 4-hour time frame

• Serum parathyroid hormone (PTH)

  Measured from baseline measures and serial blood draws over a 4-hour time frame

• Serum phosphate

  Measured from baseline measures and serial blood draws over a 4-hour time frame

• 24h Urine phosphate

  measured from two, 24-hour urine collections

Study Arms (2)

Healthy Subjects

Healthy subjects, free of CKD

Other: Phosphorus Absorption Test

Moderate CKD Subjects

Subjects with moderate-stage CKD

Other: Phosphorus Absorption Test

Interventions

Phosphorus Absorption Test OTHER

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.

Healthy Subjects; Moderate CKD Subjects

Eligibility Criteria

• Age: 30 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Healthy subjects and subjects with moderate CKD will be recruited from the community.

You may qualify if:

• 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.

You may not qualify if:

• 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

Sponsors & Collaborators

• Purdue University: lead

Study Sites (1)

Purdue University Nutrition Science Department

West Lafayette, Indiana, 47907, United States

Location

Related Publications (1)

• Stremke ER, Wiese GN, Moe SM, Wastney ME, Moorthi RN, Hill Gallant KM. Intestinal Phosphorus Absorption in Moderate CKD and Healthy Adults Determined Using a Radioisotopic Tracer. J Am Soc Nephrol. 2021 Aug;32(8):2057-2069. doi: 10.1681/ASN.2020091340. Epub 2021 Jul 8.

  PMID: 34244325 DERIVED

MeSH Terms

Conditions

Chronic Kidney Disease-Mineral and Bone Disorder; Renal Insufficiency, Chronic; Renal Insufficiency

Condition Hierarchy (Ancestors)

Rickets; Bone Diseases, Metabolic; Bone Diseases; Musculoskeletal Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Metabolic Diseases; Nutritional and Metabolic Diseases; Calcium Metabolism Disorders; Vitamin D Deficiency; Avitaminosis; Deficiency Diseases; Malnutrition; Nutrition Disorders; Hyperparathyroidism, Secondary; Hyperparathyroidism; Parathyroid Diseases; Endocrine System Diseases; Chronic Disease; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: April 5, 2017
• First Posted: April 11, 2017
• Study Start: April 25, 2018
• Primary Completion: August 30, 2019
• Study Completion: December 1, 2019
• Last Updated: July 10, 2019

Record last verified: 2019-07

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)