Hypertensive DiseasePhase 1/2NCT02697708
Retention of Potassium From Potatoes and Potassium Gluconate, and the Effect on Blood Pressure.
A Phase 1/2 study testing Potassium gluconate diet, Potato Diet and French Fries Diet in people with Hypertensive Disease, run by Purdue University at 1 site in United States.
Trial summary
This study is designed to compare the effect of different dietary potassium sources on uptake and retention of potassium, as well as to determine the effect of potassium intake on blood pressure and acid-base balance. Read more about this study
- Who is it for?
- Ages 21 years and olderHealthy volunteers can take part
- Conditions the study is for
- Hypertensive Disease
- What is being tested?
- Potassium gluconate diet, Potato Diet and French Fries Diet
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 40 participants
- Where
- 1 siteUnited States
- Study dates
- 27 Apr 2016to 31 Dec 2018
- Phase
- Phase 1/2
- Are there results?
- None posted in the registry
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 21 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age 21 and above
- Subjects able to adhere to the visit schedule and protocol requirements and be available to complete the study.
- Pre-hypertensive, (SBP: 120-159mmHg).
Who cannot join
- Subjects taking more than one medication to treat hypertension
- Subject is taking medication to treat hypotension, or medication known to affect electrolyte metabolism or contain high levels of potassium or sodium, smoke cigarettes, use illegal drugs, or excessive alcohol intake.
- Current use systemic corticosteroids, androgens, phenytoin, erythromycin, thyroid hormones, lipid-lowering medication.
- Subjects who have hypertension (SBP > 160 mmHg), hypotension (SBP < 120mmHg) or diseases known to affect potassium metabolism (kidney disease or malabsorption disorders). History of myocardial infarction, diabetes mellitus, renal disease, gastrointestinal disease, pancreatitis, cholestatic liver disease, cancer.
- Subjects who are pregnant.
- Allergy or intolerance of intervention foods.
Show all 9Show fewer
- Unwillingness to refrain from dietary supplements.
- Weight loss > 3kg in the past 2 months.
- Subjects with liver and/or lipid abnormalities (elevated alanine amino transferase (ALT) and aspartate amino transferase (AST), dyslipidemia).
Trial locations and contacts
1 site in 1 country.
United States1 site
Department of Nutrition Science Purdue University
West Lafayette, Indiana, 47907-2059
About this study
Official title: The Effect of Potatoes on Potassium Retention, Acid Base Balance, and Blood Pressure
This study is designed to compare the effect of different dietary potassium sources on uptake and retention of potassium, as well as to determine the effect of potassium intake on blood pressure and acid-base balance. The study will compare three different sources of potassium given as a supplement, potatoes or French fries.
Read the detailed description
Potassium is a shortfall nutrient according to the 2010 Dietary Guidelines for Americans. Only 3% of Americans meet the recommended Adequate Intake of 4700 mg/d for potassium. Average potassium intake is approximately half of the Recommended Dietary Allowance (RDA), with potatoes providing the highest percentage (19-20% of potassium) in the American diet. Recommended dietary potassium intakes were determined primarily to optimize protection against hypertension and secondarily to protect against stroke and coronary heart disease. In setting requirements for most minerals, bioavailability is usually considered. However, little is known about bioavailability of potassium and what is known is from supplements rather than food. Recently, we performed a potassium bioavailability study on white potatoes looking at 35 healthy, normotensive men and women at 3 levels of potassium intake as potatoes or potassium gluconate supplements. Bioavailability of potassium was determined from AUC of serial blood draws and cumulative urinary excretion. Serum potassium Area Under the Curve (AUC )increased with dose (P<0.0001) and did not differ due to source (p=0.52). Cumulative 24 h urinary potassium also increased with dose (p<0.0001) and was greater with potato than supplement (p<0.0001), concluding that bioavailability of potassium is as high from potatoes as from supplements. These data allow us to evaluate the quality of the food as a source of potassium. However, a remaining question is whether retention of potassium from potatoes is higher than from the salt, which requires a metabolic balance study to determine. The effects of potassium rich foods on blood pressure have also been recently accessed. A controlled feeding study would properly capture potassium retention and balance, as well as adequately control for any positive benefit potassium may have on blood pressure and other vascular outcomes.
Increasing potassium citrate decreased titratable acidity and improved calcium retention in a dose response manner in postmenopausal women. There is one Randomized Controlled Trial (RCT) of potassium on bone, in postmenopausal women, showing a benefit of a supplement of potassium chloride on protecting against bone loss. Similar studies have not been performed with food sources of potassium.
This study is designed to evaluate the effect of added potassium (K) from potatoes in the diet on K retention , blood pressure, and parameters related to bone health including calcium retention and acid base balance.
- Conditions
- Hypertensive Disease
- Being tested
- Potassium control diet, Potassium gluconate diet, Potato Diet, French Fries Diet
- Medical subject headings
- Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Potassium control dietDietary supplement
Also called Control Diet
No additional potassium.
Potassium gluconate dietDietary supplement
1000 mg K from potassium gluconate.
Potato DietDietary supplement
1000 mg K from potatoes.
French Fries DietDietary supplement
1000 mg K from French Fries.
| Study group | Role | What they receive |
|---|---|---|
| Control Diet | Placebo comparator | Control (no additional potassium added to diet): Arm will consist of a 16 day balance period with a basal diet set at ~2340mg K/day; based on average American intake. Receives: Dietary Supplement: Potassium control diet |
| Potassium Supplement Diet | Active comparator | Potassium gluconate: Arm will consist of a 16 day balance period with the basal (control) diet plus the addition of 1000mg of K/day from potassium gluconate (12 tablets). Receives: Dietary Supplement: Potassium gluconate diet |
| Potato Diet | Experimental | Potato diet: Arm will consist of a 16 day balance period with a basal (control) diet with an addition of 1000mg of K/day from white potatoes. Receives: Dietary Supplement: Potato Diet |
| French fries Diet | Experimental | French fry diet: Arm will consist of a 16 day balance period with a basal (control) diet with an addition of 1000mg K/day from French fries. Receives: Dietary Supplement: French Fries Diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in systolic blood pressure
Systolic blood pressure measured directly three consecutive times after 15 min of supine rest.
Measured: 1, 3, 6, 8, 10, 12, 14, 16 days
Potassium balance/retention
Twenty four hour urine and feces will be collected on all intervention days of each phase. Urine will be analyzed for creatinine, K, Na, Ca, Mg according to the urine protocol. Some urine will be stored for future analysis and the rest discarded.
Measured: Through out each day of each 16 day intervention
Potassium serum kinetics
Following breakfast, which will include the respective source of potassium or control, pooled urine will be collected at 2, 4, 6, 12 and 24.h. Blood will be drawn (5ml each draw) at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6 and 24 hours post breakfast meal. , A catheter will be inserted in the arm at baseline and will be kept there until the blood draw at 6 hours. A needle will be used for the sample at 24 hours. BP will be measured after 4, 6, and 24h.
Measured: Day 16 (24 hours) of each intervention period
Secondary outcomes (3)
Change in microcirculation
Vascular flow rate measured via Laser Doppler Flowmetry from right forearm for 60 min from the supine position.
Measured: 1, and 16 days
Change in vascular flow rate
Central blood pressure will be measured by pulse wave analysis. Measurements will be repeated at least three times within a 20 minute period after the subject has rested for at least 10 minutes in a seated position. The staff member will place a tonometer (pressure sensor) on the wrist to detect the radial pulse waveform. Measurements will be taken over the course of 5-15 minutes or until pulse wave signal reaches data acquisition parameters.
Measured: 1, 16 days
Acid-base balance
Acid-base balance will be determined on two-end of phase 24 h urine collection to relate to urinary calcium and potassium excretion. Pre-prandial arterialized blood samples will be collected anaerobically using forearm venous blood from the heated hand (10) into a polypropylene syringe containing lyophilized lithium heparin. The blood samples will be stored at room temperature and analyzed within 1 h of collection. Renal acid-base balance will be measured using urinary Net Acid Excretion (NAE) and Potential Renal Acid Load (PRAL).
Measured: 14, 15 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Mar 2016 (estimated)
- Study start27 Apr 2016
- Primary completionAug 2018 (estimated)
- Study completion31 Dec 2018 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Hypertensive DiseaseStudies of the same condition, open and under way.
- 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 1/2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Participants will receive a controlled diet containing 2340 mg potassium.(K) During the 4 - 16 day phases they will receive an additional 0 mg K, 1000 mg K from potatoes, 1000 mg K from French Fries, and 1000 mg K from supplement in randomized order. Blood pressure will be measured every other day during the intervention. There will be a 2 week washout phase during each phase.
- Masking
- None (open label)
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Purdue University
- Sponsor type
- University, hospital or other
- Collaborators
- Alliance for Potato Research and Education
- Responsible party
- Principal investigator, Berdine Martin, Purdue University
- Investigators
- Connie Weaver, PhD, Principal investigator, Purdue University, Nutrition Science
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02697708
- Sponsor's protocol ID
- 1511016780
- Status last verified
- May 2018
- First submitted
- 27 Feb 2016
- Last updated
- 9 May 2018
- Results posted
- No
- Data monitoring committee
- Yes
- Individual data sharing
- Undecided
Publications
Stone MS, Martin BR, Weaver CM. Short-Term Supplemental Dietary Potassium from Potato and Potassium Gluconate: Effect on Calcium Retention and Urinary pH in Pre-Hypertensive-to-Hypertensive Adults. Nutrients. 2021 Dec 9;13(12):4399. doi: 10.3390/nu13124399.
PubMed 34959951Stone MS, Martin BR, Weaver CM. Short-Term RCT of Increased Dietary Potassium from Potato or Potassium Gluconate: Effect on Blood Pressure, Microcirculation, and Potassium and Sodium Retention in Pre-Hypertensive-to-Hypertensive Adults. Nutrients. 2021 May 11;13(5):1610. doi: 10.3390/nu13051610.
PubMed 34064968
Study at a glance
From the registry record, last updated by the sponsor on 9 May 2018. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Potatoes on Potassium Retention, Acid Base Balance, and Blood Pressure
- ClinicalTrials.gov ID
- NCT02697708
- Acronym / sponsor ID
- 1511016780
- Conditions
- Hypertensive Disease
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Purdue UniversityUniversity, hospital or other
- Collaborators
- Alliance for Potato Research and Education
- Study start
- 27 Apr 2016 (actual)
- Primary completion
- Aug 2018 (estimated)
- Study completion
- 31 Dec 2018 (estimated)
- First posted
- 3 Mar 2016 (estimated)
- 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.
This study is designed to compare the effect of different dietary potassium sources on uptake and retention of potassium, as well as to determine the effect of potassium intake on blood pressure and acid-base balance. The study will compare three different sources of potassium given as a supplement, potatoes or French fries.
Detailed description
Potassium is a shortfall nutrient according to the 2010 Dietary Guidelines for Americans. Only 3% of Americans meet the recommended Adequate Intake of 4700 mg/d for potassium. Average potassium intake is approximately half of the Recommended Dietary Allowance (RDA), with potatoes providing the highest percentage (19-20% of potassium) in the American diet. Recommended dietary potassium intakes were determined primarily to optimize protection against hypertension and secondarily to protect against stroke and coronary heart disease. In setting requirements for most minerals, bioavailability is usually considered. However, little is known about bioavailability of potassium and what is known is from supplements rather than food. Recently, we performed a potassium bioavailability study on white potatoes looking at 35 healthy, normotensive men and women at 3 levels of potassium intake as potatoes or potassium gluconate supplements. Bioavailability of potassium was determined from AUC of serial blood draws and cumulative urinary excretion. Serum potassium Area Under the Curve (AUC )increased with dose (P<0.0001) and did not differ due to source (p=0.52). Cumulative 24 h urinary potassium also increased with dose (p<0.0001) and was greater with potato than supplement (p<0.0001), concluding that bioavailability of potassium is as high from potatoes as from supplements. These data allow us to evaluate the quality of the food as a source of potassium. However, a remaining question is whether retention of potassium from potatoes is higher than from the salt, which requires a metabolic balance study to determine. The effects of potassium rich foods on blood pressure have also been recently accessed. A controlled feeding study would properly capture potassium retention and balance, as well as adequately control for any positive benefit potassium may have on blood pressure and other vascular outcomes.
Increasing potassium citrate decreased titratable acidity and improved calcium retention in a dose response manner in postmenopausal women. There is one Randomized Controlled Trial (RCT) of potassium on bone, in postmenopausal women, showing a benefit of a supplement of potassium chloride on protecting against bone loss. Similar studies have not been performed with food sources of potassium.
This study is designed to evaluate the effect of added potassium (K) from potatoes in the diet on K retention , blood pressure, and parameters related to bone health including calcium retention and acid base balance.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 4
- Model description
- Participants will receive a controlled diet containing 2340 mg potassium.(K) During the 4 - 16 day phases they will receive an additional 0 mg K, 1000 mg K from potatoes, 1000 mg K from French Fries, and 1000 mg K from supplement in randomized order. Blood pressure will be measured every other day during the intervention. There will be a 2 week washout phase during each phase.
| Arm | Type | Receives |
|---|---|---|
| Control Diet | Placebo comparator | Dietary Supplement: Potassium control dietControl (no additional potassium added to diet): Arm will consist of a 16 day balance period with a basal diet set at ~2340mg K/day; based on average American intake. |
| Potassium Supplement Diet | Active comparator | Dietary Supplement: Potassium gluconate dietPotassium gluconate: Arm will consist of a 16 day balance period with the basal (control) diet plus the addition of 1000mg of K/day from potassium gluconate (12 tablets). |
| Potato Diet | Experimental | Dietary Supplement: Potato DietPotato diet: Arm will consist of a 16 day balance period with a basal (control) diet with an addition of 1000mg of K/day from white potatoes. |
| French fries Diet | Experimental | Dietary Supplement: French Fries DietFrench fry diet: Arm will consist of a 16 day balance period with a basal (control) diet with an addition of 1000mg K/day from French fries. |
Who may qualify
- Ages
- 21 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Age 21 and above
- Subjects able to adhere to the visit schedule and protocol requirements and be available to complete the study.
- Pre-hypertensive, (SBP: 120-159mmHg).
Key exclusion criteria (9 listed)
- Subjects taking more than one medication to treat hypertension
- Subject is taking medication to treat hypotension, or medication known to affect electrolyte metabolism or contain high levels of potassium or sodium, smoke cigarettes, use illegal drugs, or excessive alcohol intake.
- Current use systemic corticosteroids, androgens, phenytoin, erythromycin, thyroid hormones, lipid-lowering medication.
- Subjects who have hypertension (SBP > 160 mmHg), hypotension (SBP < 120mmHg) or diseases known to affect potassium metabolism (kidney disease or malabsorption disorders). History of myocardial infarction, diabetes mellitus, renal disease, gastrointestinal disease, pancreatitis, cholestatic liver disease, cancer.
- Subjects who are pregnant.
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 |
|---|---|---|
| Potassium control dietAlso: Control DietNo additional potassium. | Dietary supplement | Control Diet |
| Potassium gluconate diet1000 mg K from potassium gluconate. | Dietary supplement | Potassium Supplement Diet |
| Potato Diet1000 mg K from potatoes. | Dietary supplement | Potato Diet |
| French Fries Diet1000 mg K from French Fries. | Dietary supplement | French fries Diet |
Primary outcome
Change in systolic blood pressure
Time frame: 1, 3, 6, 8, 10, 12, 14, 16 days
Systolic blood pressure measured directly three consecutive times after 15 min of supine rest.
Potassium balance/retention
Time frame: Through out each day of each 16 day intervention
Twenty four hour urine and feces will be collected on all intervention days of each phase. Urine will be analyzed for creatinine, K, Na, Ca, Mg according to the urine protocol. Some urine will be stored for future analysis and the rest discarded.
Potassium serum kinetics
Time frame: Day 16 (24 hours) of each intervention period
Following breakfast, which will include the respective source of potassium or control, pooled urine will be collected at 2, 4, 6, 12 and 24.h. Blood will be drawn (5ml each draw) at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6 and 24 hours post breakfast meal. , A catheter will be inserted in the arm at baseline and will be kept there until the blood draw at 6 hours. A needle will be used for the sample at 24 hours. BP will be measured after 4, 6, and 24h.
3 secondary outcomes
Change in microcirculation
Time frame: 1, and 16 days
Change in vascular flow rate
Time frame: 1, 16 days
Acid-base balance
Time frame: 14, 15 days
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 May 2018.
- Derived from this study: PubMed 34959951Stone MS, Martin BR, Weaver CM. Short-Term Supplemental Dietary Potassium from Potato and Potassium Gluconate: Effect on Calcium Retention and Urinary pH in Pre-Hypertensive-to-Hypertensive Adults. Nutrients. 2021 Dec 9;13(12):4399. doi: 10.3390/nu13124399.
- Derived from this study: PubMed 34064968Stone MS, Martin BR, Weaver CM. Short-Term RCT of Increased Dietary Potassium from Potato or Potassium Gluconate: Effect on Blood Pressure, Microcirculation, and Potassium and Sodium Retention in Pre-Hypertensive-to-Hypertensive Adults. Nutrients. 2021 May 11;13(5):1610. doi: 10.3390/nu13051610.
- Individual participant dataSharing planned: Undecided
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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. This study is not recruiting at the moment.
Connie Weaver, PhD principal investigator
Purdue University, Nutrition Science
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Potassium gluconate diet, Potato Diet and French Fries Diet in people with Hypertensive Disease, run by Purdue University 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 3 inclusion and 9 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: status not confirmed, as of the sponsor's last update on 9 May 2018. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Results are not available in the source record.
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?
Change in systolic blood pressure (time frame: 1, 3, 6, 8, 10, 12, 14, 16 days). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02697708, which also lists 2 linked publications.
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 9 May 2018.