Control
Conditions
Brief summary
The investigators aim to study potential racial differences in renal phosphorus handling by provocatively testing urinary phosphorus excretion using parathyroid hormone infusions in healthy white volunteers compared to healthy black volunteers.
Interventions
DRUG1-34 parathyroid infusion
1-34 parathyroid infusion at 0.055 mcg/kg/hr for 6 hours
Sponsors
National Institutes of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
University of Miami
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* 18 years of age or older * Body mass index (BMI) within 20% ideal for their age and gender
Exclusion criteria
* Abnormal urinalysis * Pregnancy or breast-feeding * Medical conditions impacting phosphorus metabolism-primary hyperparathyroidism; diabetes mellitus; gastrointestinal malabsorption disorders; hyper- or hypothyroidism * Medications known to affect phosphorus metabolism- current use of phosphorus supplements, phosphorus binders, calcitriol or calcitriol analogues, regular antacid or laxative use, calcitonin, etidronate, 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 (Hgb \< 8 g/dl for women and \< 9 g/dl for men)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Urinary Phosphorus Excretion | six hours | Fractional excretion of phosphorus (the fraction of phosphorus filtered by the kidney which is excreted in the urine) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Fibroblast Growth Factor 23 | six hours | The change in fibroblast growth factor 23 concentrations from baseline to six hours |
| Serum Phosphorus | six hours | change in serum phosphorus from baseline to six hours |
| Serum Calcium | six hours | change in serum calcium from baseline to six hours |
| Parathyroid Hormone | six hours | change in parathyroid hormone from baseline to six hours |
| Fractional Excretion of Calcium | six hours | change in urinary fractional excretion of calcium from baseline to six hours |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| PTH Infusion (1-34) PTH infusion at a rate of 0.055 ug/kg/hour for six hours
1-34 parathyroid infusion: 1-34 parathyroid infusion at 0.055 mcg/kg/hr for 6 hours | 26 |
| Total | 26 |
Baseline characteristics
| Characteristic | PTH Infusion |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 26 Participants |
| Age, Continuous | 36 years STANDARD_DEVIATION 11 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 7 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 19 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 10 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 16 Participants |
| Region of Enrollment United States | 26 Participants |
| Sex: Female, Male Female | 5 Participants |
| Sex: Female, Male Male | 21 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 26 |
| serious Total, serious adverse events | 0 / 26 |
Outcome results
Primary
Urinary Phosphorus Excretion
Fractional excretion of phosphorus (the fraction of phosphorus filtered by the kidney which is excreted in the urine)
Time frame: six hours
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PTH Infusion | Urinary Phosphorus Excretion | 11 percentage of fractional excretion | Standard Deviation 0.5 |
Secondary
Fibroblast Growth Factor 23
The change in fibroblast growth factor 23 concentrations from baseline to six hours
Time frame: six hours
Population: adult volunteers
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PTH Infusion | Fibroblast Growth Factor 23 | 10 relative units (RU)/ml | Standard Deviation 10 |
Secondary
Fractional Excretion of Calcium
change in urinary fractional excretion of calcium from baseline to six hours
Time frame: six hours
Population: adult volunteers
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PTH Infusion | Fractional Excretion of Calcium | 0.25 percentage of fractional excretion | Standard Deviation 0.05 |
Secondary
Parathyroid Hormone
change in parathyroid hormone from baseline to six hours
Time frame: six hours
Population: adult volunteers
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PTH Infusion | Parathyroid Hormone | 9 pg/ml | Standard Deviation 3 |
Secondary
Serum Calcium
change in serum calcium from baseline to six hours
Time frame: six hours
Population: adult volunteers
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PTH Infusion | Serum Calcium | 0.4 mg/dL | Standard Deviation 0.2 |
Secondary
Serum Phosphorus
change in serum phosphorus from baseline to six hours
Time frame: six hours
Population: adult volunteers
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PTH Infusion | Serum Phosphorus | 0.4 mg/dL | Standard Deviation 0.1 |