Impact of Lowering Phosphate Additive Intake on Metabolism and Cardiovascular Health in Community-Living Adults
Primary Purpose
Healthy, Chronic Kidney Disease
Status
Completed
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
Diet
Sponsored by
About this trial
This is an interventional other trial for Healthy focused on measuring phosphorus, fibroblast growth factor 23, diet
Eligibility Criteria
Inclusion Criteria:
- (i.) Inclusion criteria for healthy volunteers: ≥18 years of age, normal kidney function (eGFR > 60 and normal urinalysis).
Exclusion Criteria:
Exclusion criteria for healthy volunteers will include:
- current smoking
- extreme obesity (BMI ≥ 35 kg/m2)
- pregnancy or breastfeeding
- conditions affecting phosphate metabolism (e.g., hyper- or hypothyroidism; irregular menses for menstruating women)
- current intake of medications that impact phosphate metabolism (high-dose vitamin D, chronic antacid use)
- current use of blood pressure medications
- abnormal serum phosphate (≥ 4.6 or < 2.5 mg/dl) or calcium levels (≥ 10.6 or < 8.5 mg/dl)
- severe anemia (hemoglobin < 8 g/dl for women and < 9 g/dl for men).
- Inability to receive weekly shipments of food at home.
- Requirement for any special diet other than a regular diet.
- Allergies to any foods in the standardized diets (ii.) Inclusion criteria for CKD patients: ≥18 years of age, eGFR 20-50 ml/min
Exclusion criteria for CKD patients will include:
- clinical need for a low potassium, low sodium or low protein diet
- new or recent change (<3 months) in dosage of medications known to impact vascular reactivity
- current smoking
- poorly controlled hypertension (≥160/100 mmHg)
- extreme obesity (BMI ≥ 35 kg/m2)
- pregnancy or breastfeeding
- conditions affecting phosphate metabolism (e.g., hyper- or hypothyroidism)
- current intake of medications that impact phosphate metabolism (e.g., high-dose vitamin D)
- abnormal serum phosphate (≥ 4.6 or < 2.5 mg/dl) or calcium levels (≥ 10.6 or < 8.5 mg/dl)
- severe anemia (hemoglobin < 8 g/dl for women and < 9 g/dl for men).
- Inability to receive weekly shipments of food at home.
- Allergies to any foods in the standardized diets
Sites / Locations
- University of Alabama
Arms of the Study
Arm 1
Arm Type
Experimental
Arm Label
single arm study
Arm Description
Outcomes
Primary Outcome Measures
Change in circulating fibroblast growth factor 23 (FGF23) concentrations
Longitudinal change in FGF23 concentrations over 8 weeks
Change in brachial flow-mediated dilatation (FMD)
Longitudinal changes in FMD over 8 weeks
Change in pulse wave velocity (PWV)
longitudinal changes in PWV over 8 weeks
Secondary Outcome Measures
Full Information
NCT ID
NCT02620449
First Posted
November 25, 2015
Last Updated
March 10, 2021
Sponsor
University of Alabama at Birmingham
1. Study Identification
Unique Protocol Identification Number
NCT02620449
Brief Title
Impact of Lowering Phosphate Additive Intake on Metabolism and Cardiovascular Health in Community-Living Adults
Official Title
Impact of Lowering Phosphate Additive Intake on Metabolism and Cardiovascular Health in Community-Living Adults (Phosphate and Fibroblast Growth Factor 23 [FGF23]: Dietary and Molecular Mediators of Health and Disparities in Cardiovascular and Kidney Diseases)
Study Type
Interventional
2. Study Status
Record Verification Date
March 2021
Overall Recruitment Status
Completed
Study Start Date
August 28, 2015 (Actual)
Primary Completion Date
March 5, 2020 (Actual)
Study Completion Date
March 30, 2020 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
University of Alabama at Birmingham
4. Oversight
Data Monitoring Committee
No
5. Study Description
Brief Summary
The purpose of the study is to learn more about how common food additives can affect phosphorus metabolism in people with normal kidney function and people with chronic kidney disease.
Detailed Description
Disturbances in phosphate homeostasis are strongly associated with cardiovascular morbidity and mortality. High dietary phosphate intake plays a central role in the development of disturbed phosphate metabolism and is common in persons consuming typical American diets rich in processed and fast foods. An important reason for the high phosphate content of these foods is the widespread use of phosphate-based food additives in the food supply. Phosphate additives are heavily utilized by the food manufacturing industry to enhance the appearance, taste and shelf-life of processed foods, accounting for as much as 50% of total phosphate intake per day. Prior work from our group suggest that high phosphate additive intake has serious cardiovascular consequences. We showed that phosphate excess induces heart disease and inflammation in experimental studies, and associates with heart disease and death independently of classic risk factors in epidemiology studies. Further, we showed that high phosphate additive intake stimulates the secretion of fibroblast growth factor 23 (FGF23), a phosphate-regulatory hormone directly implicated in the pathogenesis of cardiovascular disease. Together, these data strongly suggest that high phosphate additive intake promotes cardiovascular disease, with important potential implications for efforts to reduce disparities in cardiovascular disease. This is because individuals with low socioeconomic status have limited means to purchase healthy foods, resulting in excessive consumption of processed foods rich in phosphate additives. Moreover, low income neighborhoods have a disproportionately high prevalence of individuals with chronic kidney disease and black individuals, both groups that have impaired ability to excrete excess phosphate. Together, these data support our overriding hypothesis that high phosphate additive intake is a novel target for reducing socioeconomic and racial disparities in cardiovascular. We will test this hypothesis in detailed feeding studies of 80 individuals fed standardized meals with low phosphate additive content for 6 weeks. We will investigate the impact of reducing phosphate additive intake on changes in FGF23 levels, inflammatory markers and vascular function, and test for effect modification by race and chronic kidney disease (CKD). The results of these studies will help determine whether high phosphate additive intake is a modifiable risk factor for disparities in cardiovascular disease.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Healthy, Chronic Kidney Disease
Keywords
phosphorus, fibroblast growth factor 23, diet
7. Study Design
Primary Purpose
Other
Study Phase
Not Applicable
Interventional Study Model
Single Group Assignment
Masking
None (Open Label)
Allocation
N/A
Enrollment
50 (Actual)
8. Arms, Groups, and Interventions
Arm Title
single arm study
Arm Type
Experimental
Intervention Type
Other
Intervention Name(s)
Diet
Intervention Description
Participants will be fed a low-additive diet as the primary intervention
Primary Outcome Measure Information:
Title
Change in circulating fibroblast growth factor 23 (FGF23) concentrations
Description
Longitudinal change in FGF23 concentrations over 8 weeks
Time Frame
8 weeks
Title
Change in brachial flow-mediated dilatation (FMD)
Description
Longitudinal changes in FMD over 8 weeks
Time Frame
8 weeks
Title
Change in pulse wave velocity (PWV)
Description
longitudinal changes in PWV over 8 weeks
Time Frame
8 weeks
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria:
(i.) Inclusion criteria for healthy volunteers: ≥18 years of age, normal kidney function (eGFR > 60 and normal urinalysis).
Exclusion Criteria:
Exclusion criteria for healthy volunteers will include:
current smoking
extreme obesity (BMI ≥ 35 kg/m2)
pregnancy or breastfeeding
conditions affecting phosphate metabolism (e.g., hyper- or hypothyroidism; irregular menses for menstruating women)
current intake of medications that impact phosphate metabolism (high-dose vitamin D, chronic antacid use)
current use of blood pressure medications
abnormal serum phosphate (≥ 4.6 or < 2.5 mg/dl) or calcium levels (≥ 10.6 or < 8.5 mg/dl)
severe anemia (hemoglobin < 8 g/dl for women and < 9 g/dl for men).
Inability to receive weekly shipments of food at home.
Requirement for any special diet other than a regular diet.
Allergies to any foods in the standardized diets (ii.) Inclusion criteria for CKD patients: ≥18 years of age, eGFR 20-50 ml/min
Exclusion criteria for CKD patients will include:
clinical need for a low potassium, low sodium or low protein diet
new or recent change (<3 months) in dosage of medications known to impact vascular reactivity
current smoking
poorly controlled hypertension (≥160/100 mmHg)
extreme obesity (BMI ≥ 35 kg/m2)
pregnancy or breastfeeding
conditions affecting phosphate metabolism (e.g., hyper- or hypothyroidism)
current intake of medications that impact phosphate metabolism (e.g., high-dose vitamin D)
abnormal serum phosphate (≥ 4.6 or < 2.5 mg/dl) or calcium levels (≥ 10.6 or < 8.5 mg/dl)
severe anemia (hemoglobin < 8 g/dl for women and < 9 g/dl for men).
Inability to receive weekly shipments of food at home.
Allergies to any foods in the standardized diets
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Orlando Gutierrez, MD
Organizational Affiliation
University of Alabama at Birmingham
Official's Role
Principal Investigator
Facility Information:
Facility Name
University of Alabama
City
Birmingham
State/Province
Alabama
ZIP/Postal Code
35294
Country
United States
12. IPD Sharing Statement
Learn more about this trial
Impact of Lowering Phosphate Additive Intake on Metabolism and Cardiovascular Health in Community-Living Adults
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