The Impact of Phosphate Metabolism on Healthy Aging
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: phosphate.
- Who it may be relevant to
- Registry conditions: Hypophosphatemia, Rickets, Hypercalciuria, XLH. Basic parameters: from 13 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
Determine the association between duration and dose of chronic conventional therapy with Pi and renal (nephrocalcinosis/nephrolithiasis), vascular (endothelial function), and cardiovascular function (echo- cardiography) in patients with hereditary hypophosphatemic rickets with hypercalciuria (HHRH) and patients with X-linked hypophosphatemia (XLH).
Detailed description
The central hypothesis of this proposal is that patients with X-linked hypophosphatemia (XLH), when matched for duration and dose of phosphate (Pi) therapy to patients with hereditary hypophosphatemic rickets with hypercalciuria (HHRH), will evidence greater cardiovascular and vascular debility than patients with HHRH. The overall objectives of this project are to utilize our existing longitudinal databases for individuals with XLH and HHRH through an interdisciplinary collaboration between pediatric and adult endocrinology to: i) quantify the impact of exposure to Pi therapy across the lifespan on cardiovascular and renal complications, which are key aging endpoints, ii) determine the acute response to Pi loading in XLH and HHRH by studying the changes in surrogate markers of cardiovascular and renal function.
Interventions
- Drug phosphate
The target daily phosphate (Pi) intake is 3,500 mg/day (dietary intake plus our supplementation) for this study. Subjects will take a supplement of Pi (as KPhos Neutral 250 mg/tablet) to reach this target. Subjects will receive treatment for 30 days.
Primary outcome measures
- Parathyroid Hormone (PTH) levels [Time frame: 30 days]
- Fibroblast Growth Factor 23 (FGF23) levels [Time frame: 30 days]
Eligibility criteria
Inclusion criteria
- Children above the age of 13 years
- Younger and older adults with XLH and HHRH with confirmed NPT2c mutations affecting both copies of the NPT2c gene (HHRH) or one copy of the PHEX gene (XLH)
- Be willing to provide access to prior medical records to determine eligibility including imaging, biochemical, medical, and surgical history data
- Be willing and able to complete all aspects of the study
- Be willing to adhere to the study visit schedule and comply with the assessments (in the opinion of the investigator).
Exclusion criteria
- Subjects will be excluded, if they are children younger than age 13 years
- Subjects that have other diseases likely to impact bone and mineral metabolism (e.g. renal, hepatic, gastrointestinal disorders, and malignancy),
- Subjects that are currently pregnant,
- Subjects that received medical therapy or developed any condition, which in the opinion of the investigator, could present a concern for either subject safety or difficulty with data interpretation.
- Subjects will be excluded from Aim 2, if they are unable to tolerate supplemental phosphate.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Non-randomized
- Model
- Parallel assignment
- Masking
- Open label
- Primary purpose
- Treatment
Study locations
United States · 1 center
- Yale University School of Medicine — New Haven
Identifiers
NCT: NCT03771105 · 2000023461 · 1UL1TR001863-01