AgingNCT07149337
Assessing How the Body Responds to Increased Phosphate Intake, and How This Response Depends on Age and Sex.
A study testing Oral phosphate load in people with Aging and Kidney Disease, run by University of Zurich.
Trial summary
Kidney function declines with age and this could affect phosphate balance after an acute phosphate load (increased phosphate intake). In daily life, we regularly experience acute phosphate loads through our diet. Read more about this study
- Who is it for?
- Ages 25 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Aging, Kidney Disease, Mineral Metabolism
- What is being tested?
- Oral phosphate load
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- No sites listed yet
- Study dates
- 30 Sep 2025to Sep 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 25 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Healthy volunteers 18-25 and 63-70 years old
- 18.5 ≥ BMI < 26 kg/m2
- 0.84 ≥ phosphate in plasma ≤ 1.45 mM
- 2.20 ≥ calcium in plasma ≤ 2.50 mM
- 15 ≥ PTH in plasma ≤ 65 pg/ml
- eGFR ≥ 60 ml/min/1-73 m2
Show all 11Show fewer
- 90 ≥ Systolic blood pressure ≤ 140 mmHg
- 60 ≥ Diastolic blood pressure ≤ 85 mmHg
- No hematuria and no acute urinary tract infection
- Ability and willingness to participate in the study
- Voluntary signed inform consent
Who cannot join
- Diabetes mellitus
- Pregnancy
- History of kidney stones
- History of parathyroidectomy
- History of anorexia nervosa
- History of bulimia
Show all 20Show fewer
- History of solid organ transplantation.
- Nephrolithiasis
- Sarcoidosis
- Chronic pancreatitis
- Chronic diarrhea
- Chronic liver disease
- Complete distal renal acidosis (dRTA)
- Cystinuria
- Hypo- or hyperaldosteronism
- Hyper- or hypotension
- Hypernatremia
- Gastrointestinal disorders
- Known hypersensitivity reactions to azoic dyes, acetylsalicylic acid, as well as antirheumatic drugs and painkillers (prostaglandin synthesis inhibitors).
- Intake of vitamin D and calcium supplements, phosphate, bisphosphonates, cinacalcet, denusomab, teriparatide, systemic glucocorticoids or mineralcorticoids, antiepileptics, carboanydrase inhibitors or diuretics
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Assessing Human Phosphate Tolerance and Its Dependency on Age and Sex
Kidney function declines with age and this could affect phosphate balance after an acute phosphate load (increased phosphate intake). In daily life, we regularly experience acute phosphate loads through our diet.
The aim of this clinical study is to determine whether the body's response to increased phosphate intake changes with age and whether there are sex differences in this response.
Read the detailed description
Forty subjects (males and females aged 18-25 or 63-70) will ingest an oral phosphate load, after which their body's response will be assessed by collecting blood and urine samples over a period of ten hours.
- Conditions
- Aging, Kidney Disease, Mineral Metabolism
- Being tested
- Oral phosphate load
- Keywords
- Phosphate homeostasis and aging, Oral phosphate challenge
- Medical subject headings
- Kidney Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Oral phosphate loadOther
Participants ingest an oral phosphate load containing 558 mg of phosphorus once.
| Study group | Role | What they receive |
|---|---|---|
| Oral phosphate load | Experimental | Participants will eat a standard phosphate dinner. The next morning, after consuming a standard phosphate breakfast, they will ingest a phosphate load (558 mg phosphorus) and provide blood and urine samples for nine hours. Receives: Other: Oral phosphate load |
What is being measured
The primary outcome is the main question the study is designed to answer.
Phosphate in plasma
Phosphate in plasma 4 hours after the oral phosphate load shows age differences
Measured: The primary outcome will be measured 5 hours after the first blood collection on the day of the study and 4 hours after ingesting the oral phosphate load.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Sep 2025
- Study start30 Sep 2025 (estimated)
- Primary completion30 Sep 2026 (estimated)
- Study completionSep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AgingStudies of the same condition, open and under way.
- More trials run by University of ZurichThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Zurich
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07149337
- Sponsor's protocol ID
- 2024-02538
- Status last verified
- Aug 2025
- First submitted
- 22 Aug 2025
- Last updated
- 2 Sep 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessing Human Phosphate Tolerance and Its Dependency on Age and Sex
- ClinicalTrials.gov ID
- NCT07149337
- Acronym / sponsor ID
- 2024-02538
- Conditions
- Aging, Kidney Disease, Mineral Metabolism
- Keywords
- Phosphate homeostasis and aging, Oral phosphate challenge
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- University of ZurichUniversity, hospital or other
- Study start
- 30 Sep 2025 (estimated)
- Primary completion
- 30 Sep 2026 (estimated)
- Study completion
- Sep 2027 (estimated)
- First posted
- 2 Sep 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Kidney function declines with age and this could affect phosphate balance after an acute phosphate load (increased phosphate intake). In daily life, we regularly experience acute phosphate loads through our diet.
The aim of this clinical study is to determine whether the body's response to increased phosphate intake changes with age and whether there are sex differences in this response.
Detailed description
Forty subjects (males and females aged 18-25 or 63-70) will ingest an oral phosphate load, after which their body's response will be assessed by collecting blood and urine samples over a period of ten hours.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Oral phosphate load | Experimental | Other: Oral phosphate loadParticipants will eat a standard phosphate dinner. The next morning, after consuming a standard phosphate breakfast, they will ingest a phosphate load (558 mg phosphorus) and provide blood and urine samples for nine hours. |
Who may qualify
- Ages
- 25 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (11 listed)
- Healthy volunteers 18-25 and 63-70 years old
- 18.5 ≥ BMI < 26 kg/m2
- 0.84 ≥ phosphate in plasma ≤ 1.45 mM
- 2.20 ≥ calcium in plasma ≤ 2.50 mM
- 15 ≥ PTH in plasma ≤ 65 pg/ml
Key exclusion criteria (20 listed)
- Diabetes mellitus
- Pregnancy
- History of kidney stones
- History of parathyroidectomy
- History of anorexia nervosa
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Oral phosphate loadParticipants ingest an oral phosphate load containing 558 mg of phosphorus once. | Other | Oral phosphate load |
Primary outcome
Phosphate in plasma
Time frame: The primary outcome will be measured 5 hours after the first blood collection on the day of the study and 4 hours after ingesting the oral phosphate load.
Phosphate in plasma 4 hours after the oral phosphate load shows age differences
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Sep 2025.
Related trials for Aging
Recruiting
Feasibility of A Smartphone Application Intervention in Community Settings: A Pretest-Posttest Pilot Study
Aging, Dementia
Not yet recruitingObservational study
Prospective Research on Identification of Dementia in Early Stages (P.R.I.D.E)
Mild Cognitive Impairment, Memory Disorders
RecruitingObservational study
PET Imaging in the Baltimore Longitudinal Study of Aging (BLSA)
Aging
RecruitingPhase 2
Neuroplasticity Enhancement From Cognitive Training Reinforced by Psilocybin
Alzheimer's Disease
Recruiting
Plant-based Diet in Older People: What Consequences for Muscle Health?
Aging
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
A study testing Oral phosphate load in people with Aging and Kidney Disease, run by University of Zurich.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 11 inclusion and 20 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 2 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Carsten A Wagner, Prof. MD (41 44 635 50 23, carsten.wagner@physiol.uzh.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Phosphate in plasma (time frame: The primary outcome will be measured 5 hours after the first blood collection on the day of the study and 4 hours after ingesting the oral phosphate load.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Sep 2025.