Healthy
Conditions
Keywords
phosphorus-based food additives, phosphorus metabolism
Brief summary
The purpose of the study is to learn more about how phosphorus-based food additives affect phosphorus metabolism in people with normal kidney function.
Detailed description
Phosphorus is a mineral that is found in foods such as dairy products, nuts, and meat, and is important for strengthening the bones. However, too much phosphorus in the blood may be bad for the health of your heart and blood vessels. The kidneys keep the blood levels of phosphorus normal by getting rid of extra phosphorus in the urine. New research has found that common forms of food additives that are high in phosphorus may increase blood phosphorus levels in individuals with kidney disease. In addition, these food additives may increase blood levels of hormones that control phosphorus such as parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23). Like high blood phosphorus levels, high levels of PTH and FGF23 in the blood may also be bad for the health of your heart and blood vessels. In this study, the investigators would like to examine the effects of food additives on blood levels of phosphorus, PTH and FGF23 in individuals with normal kidney function.
Interventions
OTHERResearch diet
Participants will be provided specially prepared meals to eat at home for two weeks. During the first week, participants will eat foods that do not have any phosphorus-based food additives in them (this is called the control diet). During the second week, participants will eat foods that all have phosphorus-based food additives in them (called the intervention diet).
Sponsors
University of Alabama at Birmingham
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
19 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy volunteers, 19 - 45 years of age
Exclusion criteria
* abnormal urinalysis-presence of hematuria, proteinuria, or leukocyturia. * pregnancy or breast-feeding * Medical conditions impacting phosphate metabolism-primary hyperparathyroidism; gastrointestinal malabsorption disorders such as Crohn's Disease, ulcerative colitis, celiac disease, or liver dysfunction; hyper- or hypothyroidism; irregular menses for female subjects. * Body Mass Index (BMI) ≥ 30 g/m2 since obesity is independently associated with impaired phosphorus metabolism. * Medications known to affect phosphorus metabolism- current use of phosphorus supplements, high-dose or activated vitamin D compounds, regular antacid or laxative use, anticonvulsants. * Hyper- or hypophosphatemia (≥ 4.6 mg/dl or ≤ 2.5 mg/dl respectively), hyper- or hypocalcemia (≥ 10.6 or ≤ 8.5 mg/dl respectively), or severe anemia (hemoglobin \< 8 g/dl for women and \< 9 g/dl for men).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| FGF23 | 2 weeks | Change in FGF23 levels |
| PTH | 2 weeks | Change in PTH levels over 2 weeks |
| Serum phosphate | 2 weeks | Change in serum phosphate over two weeks |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Insulin sensitivity as measured by HOMA-IR | 2 weeks | changes in HOMA-IR over two weeks |
| Brachial flow mediated dilatation measured by ultrasound | 2 weeks | change in flow mediated dilatation over two weeks |
Countries
United States
Outcome results
None listed