OsteoporosisNCT06811363
Contribution of Bone to Urine Citrate
An observational study of Osteoporosis, run by University of Texas Southwestern Medical Center at 1 site in United States.
Trial summary
Identification of the mechanisms by which bone contributes to urine citrate could lead to alternative explanations for and approaches to hypocitraturia. This proposal to explore the role of bone in urine citrate addresses the mission of the CMMCR to discover new mechanisms and innovative therapies for diseases of… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Osteoporosis
- What is being tested?
- Metabolic / prescribed diet, KCit Load (40 meq) and Anti-resorptive agents
- How many people
- 25 participants
- Where
- 1 siteUnited States
- Study dates
- Jun 2026to Mar 2027
- Phase
- Observational
- 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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients with osteoporosis
Who may be able to join
- Osteoporosis naïve to treatment
Who cannot join
- eGFR < 60 ml/min
- chronic diarrhea or gastrointestinal illness
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Identification of the mechanisms by which bone contributes to urine citrate could lead to alternative explanations for and approaches to hypocitraturia. This proposal to explore the role of bone in urine citrate addresses the mission of the CMMCR to discover new mechanisms and innovative therapies for diseases of mineral metabolism. The results will be used to apply for extramural funding to further examine the nonrenal regulation of UCit.
Hypothesis: Serum citrate is a function of bone citrate formation dependent on both bone mass and bone turnover. 20 subjects with osteoporosis naïve to treatment will be identified to examine bone parameters that correlate with ΔUcit/Δk.
Read more
Use of potent anti-osteoporotic therapies to increase the likelihood of identifying significant bone turnover and BMD correlations with ΔUcit/Uk will take place in this study.
Plan to achieve the following aim:
- Correlate ∆ Ucit/∆k in response to acute KCit load with:
- Bone turnover marker at baseline
- BMD at baseline
- Change in bone turnover markers at 1 month and 6 months with each osteoporosis treatment modality (anti-resorptive agents such as Zoledronic acid or Denosumab, or the Anabolic agent Romosozumab)
- Change in bone mineral density at 6 with each osteoporosis treatment modality (anti-resorptive agents such as Zoledronic acid or Denosumab, or the Anabolic agent Romosozumab)
Read the detailed description
Screening Visit: Before enrollment into the trial, potential candidates will undergo screening, whereby the study team will conduct a physical exam and ask questions about the subject's medical history, including medications and any surgical procedures. Those who meet the entry-exclusion criteria will be selected for consideration into the study. During screening, subjects will provide information on or have the following exams, tests or procedures:
- Social and medical history;
- Medications;
- Vital signs;
- Demographic information (age, gender, ethnic origin);
- Personal information (name, date of birth, address, telephone number, emergency contact, and referring physician)
Assignment to groups:
Group 1- Patients with osteoporosis naïve to treatment will initiate treatment with anti-resorptive agents (zoledronic acid or denosumab).
Group 2- - Patients with osteoporosis naïve to treatment will initiate treatment with anabolic agents (romosozumab).
The anti-osteoporosis medication would be prescribed by the treating physician.
Phase 1 (pre-treatment phase):
All patients will be stabilized with instructed diet (400 mg Ca, 800 mg P, 100 mEq Na) and two liters of distilled water daily for three days (equilibration period), followed by a constant standardized meal with the same composition of Ca, P, and Na for one day (stabilization period) and undergo a run-in (pre-Rx) period.
One 24-hour urine will be obtained on day 4 without mineral oil (stabilization period). The 24-hour urine will be analyzed for total volume, pH, creatinine, sodium, potassium, calcium, magnesium, phosphorus chloride, oxalate, citrate, ammonium, titratable acidity, bicarbonate and deoxypyridinoline (DPD). The patient will be fasted from 9 pm of the preceding evening except for 300 ml of distilled water at 9 pm and 11 pm. On test days, 600 ml of distilled water will be given at 7 am and fasting blood will be obtained tested for Serum BMP, citrate and bone turnover markers (CTX, P1NP, bone alkaline phosphatase).
Potassium citrate load of 40meq will be given after fasting blood has been obtained and hourly blood and urine measurements of citrate and creatinine for 4 hours after ingesting will be collected.
Laboratory Analysis:
Urine samples - Post-load every 1 hour for 4 hours analyzed for citrate and creatinine by Mineral Metabolism Laboratory.
Blood samples - Post-load every 1 hour for 4 hours analyzed for citrate and creatinine by Mineral Metabolism Laboratory.
Phase 2 (1 month after initiating treatment) and Phase 3 (6 months after initiating treatment):
These two visits consist of identical study procedure as Phase 1.
Imaging:
Imagining studies will be done using DXA for bone density measurement and micro-CT measurement for determaination of bone quality and microarchitecture of the bone. The imaging studies will be performed during phase 1 and phase 3.
- Conditions
- Osteoporosis
- Being tested
- Metabolic / prescribed diet, KCit Load (40 meq), Anti-resorptive agents, Anabolic Agents
- Keywords
- naïve to treatment, bone mass, bone turnover
- Medical subject headings
- Osteoporosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Metabolic / prescribed dietOther
Instructed diet (400 mg Ca, 800 mg P, 100 mEq Na) and two liters of distilled water daily for three days (equilibration period), followed by a constant standardized meal with the same composition of Ca, P, and Na for one day. After 240hr urine sample collection patient fasted the preceding evening except for 300 ml of distilled water at 9 pm and 11 pm. On test days, 600 ml distilled water given and fasting blood obtained.
KCit Load (40 meq)Other
Potassium citrate load of 40meq will be given after fasting blood has been obtained
Anti-resorptive agentsDrug
Zoledronic acid or Denosumab (as prescribed by their physician)
Anabolic AgentsDrug
Romosozumab (as prescribed by their physician)
| Study group | Role | What they receive |
|---|---|---|
| Anti-resorptive agents use Group | Patients with osteoporosis naïve to treatment will initiate treatment with anti-resorptive agents (zoledronic acid or denosumab) Receives: Other: Metabolic / prescribed diet; Other: KCit Load (40 meq); Drug: Anti-resorptive agents | |
| Anabolic agents use Group | Patients with osteoporosis naïve to treatment will initiate treatment with anabolic agents (romosozumab) Receives: Other: Metabolic / prescribed diet; Other: KCit Load (40 meq); Drug: Anabolic Agents |
What is being measured
The primary outcome is the main question the study is designed to answer.
Correlation of change in Urine Citrate levels to change in Potassium levels with change in bone turnover markers at 1 month after initiating treatment
Change in Urine Citrate levels to change in Potassium levels from the 24h urine samples is measured and will be correlated with baseline and post treatment bone turnover markers by multiple linear regression modeling using forward and backward selection.
Measured: Baseline, 1month after initiating treatment
Correlation of change in Urine Citrate levels to change in Potassium levels with change in bone turnover markers at 6 months after initiating treatment
Change in Urine Citrate levels to change in Potassium levels from the 24h urine samples is measured and will be correlated with baseline and post treatment bone turnover markers by multiple linear regression modeling using forward and backward selection.
Measured: Baseline, 6 months after initiating treatment
Correlation of change in Urine Citrate levels to change in Potassium levels with bone densitometry at baseline
Change in Urine Citrate levels to change in Potassium levels will be correlated with bone densitometry at lumbar spine, right hip, and radius
Measured: Baseline
Correlation of change in Urine Citrate levels to change in Potassium levels with change in bone densitometry at 6 months after initiating treatment
Change in Urine Citrate levels to change in Potassium levels will be correlated with change in bone densitometry at lumbar spine, right hip, and radius
Measured: Baseline, 6 months after initiating treatment
K Cit load
The AUC for citrate will be calculated from the serum and urine levels based on the assumption that oral K Cit is 100% absorbed to estimate hepatic uptake effect on filtered load. The fractional excretion of citrate (FeCit) will be calculated from hourly serum and urine creatinine and citrate levels (FeCit = (serum Cit x Urine Cr)/urine Cit x serum Cr) x 100. Differences in FeCit will be correlated with ΔUcit/Δk and will be used to discriminate changes in ΔUcit/Δk due to filtered load vs renal handling.
Measured: Predose, 0.5, 1, 2, 3, 4 hours after drug administration in Phases 1, 2, 3
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Feb 2025
- Study startJun 2026 (estimated)
- Primary completionMar 2027 (estimated)
- Study completionMar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for OsteoporosisStudies of the same condition, open and under way.
- More trials run by University of Texas Southwestern Medical CenterThe 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 25 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Texas Southwestern Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Eleanor Lederer, University of Texas Southwestern Medical Center
- Investigators
- Eleanor Lederer, MD, Principal investigator, University of Texas Southwestern Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06811363
- Sponsor's protocol ID
- STU-2024-0760
- Status last verified
- May 2026
- First submitted
- 31 Jan 2025
- Last updated
- 3 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Individual participant data that underlie the results reported in this article, after deidentification (text, tables, figures, and appendices) for individual participant data meta-analysis.
Study at a glance
From the registry record, last updated by the sponsor on 3 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Contribution of Bone to Urine Citrate
- ClinicalTrials.gov ID
- NCT06811363
- Acronym / sponsor ID
- STU-2024-0760
- Conditions
- Osteoporosis
- Keywords
- naïve to treatment, bone mass, bone turnover
- Study type
- Observational
- Recruitment status
- Enrolling by invitation
- Enrolment
- 25 participants (estimated)
- Lead sponsor
- University of Texas Southwestern Medical CenterUniversity, hospital or other
- Study start
- Jun 2026 (estimated)
- Primary completion
- Mar 2027 (estimated)
- Study completion
- Mar 2027 (estimated)
- First posted
- 6 Feb 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.
Identification of the mechanisms by which bone contributes to urine citrate could lead to alternative explanations for and approaches to hypocitraturia. This proposal to explore the role of bone in urine citrate addresses the mission of the CMMCR to discover new mechanisms and innovative therapies for diseases of mineral metabolism. The results will be used to apply for extramural funding to further examine the nonrenal regulation of UCit.
Hypothesis: Serum citrate is a function of bone citrate formation dependent on both bone mass and bone turnover. 20 subjects with osteoporosis naïve to treatment will be identified to examine bone parameters that correlate with ΔUcit/Δk.
Use of potent anti-osteoporotic therapies to increase the likelihood of identifying significant bone turnover and BMD correlations with ΔUcit/Uk will take place in this study.
Plan to achieve the following aim:
- Correlate ∆ Ucit/∆k in response to acute KCit load with:
- Bone turnover marker at baseline
- BMD at baseline
- Change in bone turnover markers at 1 month and 6 months with each osteoporosis treatment modality (anti-resorptive agents such as Zoledronic acid or Denosumab, or the Anabolic agent Romosozumab)
- Change in bone mineral density at 6 with each osteoporosis treatment modality (anti-resorptive agents such as Zoledronic acid or Denosumab, or the Anabolic agent Romosozumab)
Detailed description
Screening Visit: Before enrollment into the trial, potential candidates will undergo screening, whereby the study team will conduct a physical exam and ask questions about the subject's medical history, including medications and any surgical procedures. Those who meet the entry-exclusion criteria will be selected for consideration into the study. During screening, subjects will provide information on or have the following exams, tests or procedures:
- Social and medical history;
- Medications;
- Vital signs;
- Demographic information (age, gender, ethnic origin);
- Personal information (name, date of birth, address, telephone number, emergency contact, and referring physician)
Assignment to groups:
Group 1- Patients with osteoporosis naïve to treatment will initiate treatment with anti-resorptive agents (zoledronic acid or denosumab).
Group 2- - Patients with osteoporosis naïve to treatment will initiate treatment with anabolic agents (romosozumab).
The anti-osteoporosis medication would be prescribed by the treating physician.
Phase 1 (pre-treatment phase):
All patients will be stabilized with instructed diet (400 mg Ca, 800 mg P, 100 mEq Na) and two liters of distilled water daily for three days (equilibration period), followed by a constant standardized meal with the same composition of Ca, P, and Na for one day (stabilization period) and undergo a run-in (pre-Rx) period.
One 24-hour urine will be obtained on day 4 without mineral oil (stabilization period). The 24-hour urine will be analyzed for total volume, pH, creatinine, sodium, potassium, calcium, magnesium, phosphorus chloride, oxalate, citrate, ammonium, titratable acidity, bicarbonate and deoxypyridinoline (DPD). The patient will be fasted from 9 pm of the preceding evening except for 300 ml of distilled water at 9 pm and 11 pm. On test days, 600 ml of distilled water will be given at 7 am and fasting blood will be obtained tested for Serum BMP, citrate and bone turnover markers (CTX, P1NP, bone alkaline phosphatase).
Potassium citrate load of 40meq will be given after fasting blood has been obtained and hourly blood and urine measurements of citrate and creatinine for 4 hours after ingesting will be collected.
Laboratory Analysis:
Urine samples - Post-load every 1 hour for 4 hours analyzed for citrate and creatinine by Mineral Metabolism Laboratory.
Blood samples - Post-load every 1 hour for 4 hours analyzed for citrate and creatinine by Mineral Metabolism Laboratory.
Phase 2 (1 month after initiating treatment) and Phase 3 (6 months after initiating treatment):
These two visits consist of identical study procedure as Phase 1.
Imaging:
Imagining studies will be done using DXA for bone density measurement and micro-CT measurement for determaination of bone quality and microarchitecture of the bone. The imaging studies will be performed during phase 1 and phase 3.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Anti-resorptive agents use Group | – | Other: Metabolic / prescribed diet, Other: KCit Load (40 meq), Drug: Anti-resorptive agentsPatients with osteoporosis naïve to treatment will initiate treatment with anti-resorptive agents (zoledronic acid or denosumab) |
| Anabolic agents use Group | – | Other: Metabolic / prescribed diet, Other: KCit Load (40 meq), Drug: Anabolic AgentsPatients with osteoporosis naïve to treatment will initiate treatment with anabolic agents (romosozumab) |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with osteoporosis
Key inclusion criteria (1 listed)
- Osteoporosis naïve to treatment
Key exclusion criteria (2 listed)
- eGFR < 60 ml/min
- chronic diarrhea or gastrointestinal illness
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 |
|---|---|---|
| Metabolic / prescribed dietInstructed diet (400 mg Ca, 800 mg P, 100 mEq Na) and two liters of distilled water daily for three days (equilibration period), followed by a constant standardized meal with the same composition of Ca, P, and Na for one day. After 240hr urine sample collection patient fasted the preceding evening except for 300 ml of distilled water at 9 pm and 11 pm. On test days, 600 ml distilled water given and fasting blood obtained. | Other | Anabolic agents use Group, Anti-resorptive agents use Group |
| KCit Load (40 meq)Potassium citrate load of 40meq will be given after fasting blood has been obtained | Other | Anabolic agents use Group, Anti-resorptive agents use Group |
| Anti-resorptive agentsZoledronic acid or Denosumab (as prescribed by their physician) | Drug | Anti-resorptive agents use Group |
| Anabolic AgentsRomosozumab (as prescribed by their physician) | Drug | Anabolic agents use Group |
Primary outcome
Correlation of change in Urine Citrate levels to change in Potassium levels with change in bone turnover markers at 1 month after initiating treatment
Time frame: Baseline, 1month after initiating treatment
Change in Urine Citrate levels to change in Potassium levels from the 24h urine samples is measured and will be correlated with baseline and post treatment bone turnover markers by multiple linear regression modeling using forward and backward selection.
Correlation of change in Urine Citrate levels to change in Potassium levels with change in bone turnover markers at 6 months after initiating treatment
Time frame: Baseline, 6 months after initiating treatment
Change in Urine Citrate levels to change in Potassium levels from the 24h urine samples is measured and will be correlated with baseline and post treatment bone turnover markers by multiple linear regression modeling using forward and backward selection.
Correlation of change in Urine Citrate levels to change in Potassium levels with bone densitometry at baseline
Time frame: Baseline
Change in Urine Citrate levels to change in Potassium levels will be correlated with bone densitometry at lumbar spine, right hip, and radius
Correlation of change in Urine Citrate levels to change in Potassium levels with change in bone densitometry at 6 months after initiating treatment
Time frame: Baseline, 6 months after initiating treatment
Change in Urine Citrate levels to change in Potassium levels will be correlated with change in bone densitometry at lumbar spine, right hip, and radius
K Cit load
Time frame: Predose, 0.5, 1, 2, 3, 4 hours after drug administration in Phases 1, 2, 3
The AUC for citrate will be calculated from the serum and urine levels based on the assumption that oral K Cit is 100% absorbed to estimate hepatic uptake effect on filtered load. The fractional excretion of citrate (FeCit) will be calculated from hourly serum and urine creatinine and citrate levels (FeCit = (serum Cit x Urine Cr)/urine Cit x serum Cr) x 100. Differences in FeCit will be correlated with ΔUcit/Δk and will be used to discriminate changes in ΔUcit/Δk due to filtered load vs renal handling.
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 3 Jun 2026.
- Individual participant dataSharing planned: Yes. Individual participant data that underlie the results reported in this article, after deidentification (text, tables, figures, and appendices) for individual participant data meta-analysis.
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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.
Eleanor Lederer, MD principal investigator
University of Texas Southwestern Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Osteoporosis, run by University of Texas Southwestern Medical Center at 1 site in United States.
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 1 inclusion and 2 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: enrolling by invitation, as of the sponsor's last update on 3 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Correlation of change in Urine Citrate levels to change in Potassium levels with change in bone turnover markers at 1 month after initiating treatment (time frame: Baseline, 1month after initiating treatment). The study lists 5 primary outcomes in all. 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 3 Jun 2026.