Chronic Kidney Disease in Relation to Alterations in Protein and Amino Acid Metabolism and Function

Weight loss commonly occurs in patients with chronic kidney disease (CKD), negatively influencing their quality of life, treatment response and survival. Loss of muscle protein is generally a central component of weight loss in CKD patients but patients also have reductions in fat mass and bone density, independent of the severity of the disease state. Attempts to reverse weight and muscle loss in CKD and improve nutritional status by nutritional supplementation have been unsuccessful and there are currently no approved therapies.

Purpose of this study is to provide detailed insight in disease related gut function by obtaining information on gut permeability, digestion and absorption of glucose, fat and protein in CKD patients compared to matched healthy controls. Additionally, to examine whether protein and amino acid metabolism is disturbed in CKD patients compared to healthy controls. This will provide required information that will lead to implement new strategies to develop optimal nutritional regimen in order to enhance nutritional status, quality of life and survival in relation to kidney disease.

Study Overview

• Status: Withdrawn
• Conditions: Chronic Kidney Failure
• Intervention / Treatment: Dietary supplement: Boost High Protein

Detailed Description

This study involves one test day of approximately 7-8 hours. On this test day subjects will ingest a sugar drink to assess gut permeability and gut function, and a protein meal to measure digestion/absorption and the anabolic response to food intake. Subjects will also receive a mixture of amino acids that are made a little heavier than normal, called stable isotopes. This stable isotopes is used to investigate protein behavior in the body (protein kinetics). Blood (100-120 ml in total) and urine samples will be collected over 7.5 hours.

• Study Type: Interventional
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Texas
    • College Station, Texas, United States, 77843
      • Texas A&M University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 55 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion criteria CKD subjects

• Ability to walk, sit down and stand up independently
• Age 55 years or older
• Ability to lie in supine or elevated position for 7 hours
• Diagnosis of kidney disease; undergoing hemodialysis
• Clinically stable condition; no hospitalization 4 weeks preceding first study day
• Willingness and ability to comply with the protocol

Inclusion criteria healthy subjects:

• Healthy male or female according to the investigator's or appointed staff's judgment
• Ability to walk, sit down and stand up independently
• Age 55 years or older (older control group)
• Ability to lay in supine or elevated position for 7 hours
• No diagnosis of CKD
• Willingness and ability to comply with the protocol

Exclusion Criteria all subjects:

• Any condition that may interfere with the definition 'healthy subject' according to the investigator's judgment (healthy subjects only)
• Established diagnosis of malignancy
• Established diagnosis of Insulin Dependent Diabetes Mellitus
• History of untreated metabolic diseases including hepatic disorder
• Presence of acute illness or metabolically unstable chronic illness
• Presence of fever within the last 3 days
• Body mass index >40 kg/m2 (healthy subjects only)
• Any other condition that would interfere with the study or safety of the patient (according to the PI or nurse)
• Use of protein or amino acid containing nutritional supplements within 5 days of first study day
• Use of long-term oral corticosteroids or short course of oral corticosteroids within 4 weeks preceding first study day
• Failure to give informed consent or Investigator's uncertainty about the willingness or ability of the subject to comply with the protocol requirements
• (Possible) pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Boost High Protein; Boost high protein with added spirulina	Dietary supplement: Boost High Protein; Subjects will receive stable amino acid isotopes IV and will receive Boost High Protein with added isotopes to measure anabolic response to a meal.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Net whole-body protein synthesis	Change in whole-body protein synthesis rate after intake of meal	0, 15, 30, 45, 60, 75, 90, 105, 120, 150, 180, 210 min post-meal

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Glucose absorption	Recovery of 3-O-Methyl-D-glucose in the urine.	7 hours
Skeletal and respiratory muscle strength	Difference in leg strength and fatigue, handgrip strength and fatigue, and inspiratory and expiratory pressure between heart failure patients and healthy controls.	1 day
Cognitive function	Outcome of neuro-psychological tests in heart failure patients and healthy controls in relation to the tryptophan metabolism	1 day
Fatty acid digestion after feeding	Enrichment in palmitic acid and tripalmitin fatty acids in plasma	0,15,30,45,60,75,90,105,120,150,180,210 min post-meal
Protein digestion after feeding	Ratio enrichment free phenylalanine vs phenylalanine from protein spirulina	0,15,30,45,60,75,90,105,120,150,180,210, min post-meal
Whole body collagen breakdown rate	Hydroxyproline enrichment in plasma	Postabsorptive state during 3 hours
Tryptophan turnover rate	Tryptophan enrichment in plasma	Postabsorptive state during 3 hours
Arginine turnover rate	Arginine enrichment in plasma	Postabsorptive state during 3 hours
Insulin response to feeding	Acute change from postabsorptive state after intake of meal	During 3 hours after feeding
Fat-free mass	Characteristics of study subjects	Postabsorptive state during 15 min
Glycine rate of appearance	Glycine enrichment in plasma	Postabsorptive state during 3 hours
Taurine turnover rate	Enrichment of taurine in plasma	Postabsorptive state during 3 hours
Citrulline Rate of appearance	Plasma enrichment of citrulline	Postabsorptive state during 3 hours
Gut permeability	Recovery of rhamnose/lactulose in urine	7 hours
Myofibrillar protein breakdown rate	3-Methylhistidine enrichment in plasma	0,15,30,45,60,75,90,105,120,150,180,210 min post-meal

Collaborators and Investigators

• Sponsor: Texas A&M University

Study record dates

Study Major Dates

• Study Start: June 1, 2013
• Primary Completion (Anticipated): December 1, 2015
• Study Completion (Anticipated): December 1, 2016

Study Registration Dates

• First Submitted: June 27, 2013
• First Submitted That Met QC Criteria: June 27, 2013
• First Posted (Estimate): July 2, 2013

Study Record Updates

• Last Update Posted (Estimate): May 1, 2015
• Last Update Submitted That Met QC Criteria: April 29, 2015
• Last Verified: April 1, 2015

More Information

Terms related to this study

• Keywords: CKD; Hemodialysis; Muscle Function; Protein Digestion; Fat Digestion; Gut Function; Glucose Absorption
• Additional Relevant MeSH Terms: Urologic Diseases; Kidney Diseases; Renal Insufficiency, Chronic; Kidney Failure, Chronic; Renal Insufficiency
• Other Study ID Numbers: 2013-0294