Bone Diseases, MetabolicNUCNCT01509456
The Effect of Potassium Bicarbonate on Bone and Several Physiological Systems During Immobilisation
A study testing Potassium Bicarbonate in people with Bone Diseases, Metabolic and Acid-Base Imbalance, run by DLR German Aerospace Center at 1 site in Germany.
Trial summary
Mainly due to the absence of gravitational forces in weightlessness, astronauts suffer from an increased bone loss- negatively affecting health and vitality during a mission. The development of effective countermeasures to this loss includes many different aspects like sports but also nutrition. Read more about this study
- Who is it for?
- Ages 20 to 45 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Bone Diseases, Metabolic, Acid-Base Imbalance, Muscular Atrophy
- What is being tested?
- Potassium Bicarbonate
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 8 participants
- Where
- 1 siteGermany
- Study dates
- Feb 2010to Oct 2010
- Phase
- Interventional
- 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 20 to 45 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- healthy male subjects
- age: 20- 45
- weight 65- 85 kg
- height: 158- 190 cm
- BMI 20- 26 kg/m2
- no high performance sports
Show all 11Show fewer
- non- smoking (minimum 6 months prior to study start)
- willing to complete both parts of the study
- presentation of social security and criminal record
- successful completion of medical and psychological screening
- signed informed consent
Who cannot join
- drugs- and alcohol abuse
- antiinflammatory drugs taken during the study
- vegetarianism, veganism
- migraine
- psychical illness in the past
- claustrophobia
Show all 30Show fewer
- hiatal hernia
- gastroesophageal reflux
- diabetes mellitus
- Rheumatic disease
- muscle or joint disease
- disc prolapse
- orthostatic intolerance
- Hyperlipidaemia
- renal disease
- thyroid dysfunction
- hyperhomocysteinaemia
- hyper-/hypouremia
- hyper-/hypocalcemia
- anaemia
- hypoferremia
- Vitamin D deficiency
- deviation of blood gases from normal values (pH 7,38 - 7,42; pO2 79 - 98 mmHg; pCO2 34 - 45 mmHg; HCO3 20 - 28 mmol/l; Base excess ± 2 mmol/l)
- risk of thrombosis
- chronic back pain
- bone fracture within one year prior to study start
- bone mineral density 1,5 SD ≤ t-Score
- metal implants or other osteosynthesis material
- subject within another clinical trial within 2 months prior to study start
- any other status which according to the apprehension of the principal investigator leads to the exclusion of the subject
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Effect of Potassium Bicarbonate on Bone and the Immune System During 21 Days of 6° Head- Down- Tilt Bedrest (HDT- Bedrest)
Mainly due to the absence of gravitational forces in weightlessness, astronauts suffer from an increased bone loss- negatively affecting health and vitality during a mission. The development of effective countermeasures to this loss includes many different aspects like sports but also nutrition.
Alkaline salts, abundant in fruits and vegetables, have shown to have positive effects on markers of bone turnover of postmenopausal women but also men and younger adults. With the current study the effects of a potassium bicarbonate supplementation added to a standardised, strictly controlled, definite diet of healthy, young men, should be verified within 21 days of 6°- HDT- Bedrest- the gold standard of simulating weightlessness within earthbound conditions.
Read the detailed description
Astronauts in space suffer from an increased bone loss which is mainly related to the absence of gravitational forces. This increased bone reduction is accompanied by an higher concentration of calcium in urine and in this respect enhancing the risk of renal stones. Due to the fact, that bones´ regeneration does not occur rapidly even after returning to earth, astronauts face an increased risk of osteoporosis.
Nutritional factors such as a deficient intake of calcium, energy and fluid and the abundant intake of table salt exhibit additional negative effects on bone. Results of several studies consistently show the negative effects of acids on bone (increased bone loss). With respect to space missions of longer duration one big challenge is the development of countermeasures for the negative consequences of weightlessness on bone.
As not all needed experiments for the development of countermeasures can be conducted in space, simulation models of weightlessness such as 6° Head- Down- Tilt- Bedrest (HDT- Bedrest) have been implemented on earth, miming some physiological conditions of weightlessness such as unloading and immobilisation of the lower parts of the body and the fluid shift.
Alkaline salts, such as potassium bicarbonate (KHCO3), demonstrate positive effects on bone when being supplemented to postmenopausal women. Apart from the positive effects on markers of bone turnover, calcium concentration in urine could be reduced. Thus, the main aim of the present study was to reduce the immobilization induced bone resorption through an alkalizing effect of the alkaline salt KHCO3's supplementation during Head- Down- Tilt- Bedrest (HDT- Bedrest)-a leading simulation model of weightlessness.
The crossover designed study consisted of two parts of equal length (36 days)- 7 days of adaptation, 21 days of HDT- Bedrest, 6 days recovery and 2 days of long- term follow- up. Both study parts only differed in the HDT- period, where one group of the 8 healthy, young, male participating subjects was supplemented with 90 mmol KHCO3 daily (3 times a day 30 mmol KHCO3 diluted in 200 ml tab water, supplemented together with the main meals), while the other group only received 200 ml of tab water without any supplementation (Control group).
The measurements of bone formation markers as well as bone resorption markers in blood and urine supply insight into the influences of the supplementation on bone metabolism while blood gas analysis together with the pH- values of the 24h- urine point out the alkalising effects of KHCO3. Further physiological systems like protein and muscle metabolism, body weight and body composition, circulation and the neuro- vestibular system are simultaneously under investigation.
- Conditions
- Bone Diseases, Metabolic, Acid-Base Imbalance, Muscular Atrophy, Sprains and Strains, Protein Metabolism, Body Weight Changes
- Being tested
- Potassium Bicarbonate
- Keywords
- bone metabolism, potassium bicarbonate, alkaline salt, acid base balance, bed rest
- Medical subject headings
- Bone Diseases, Metabolic, Acid-Base Imbalance, Muscular Atrophy, Sprains and Strains, Body Weight Changes, Cardiovascular Abnormalities
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Potassium BicarbonateDietary supplement
90 mmol daily, effervescent tablets 30 mmol diluted in 200 ml tab water supplemented three times a day together with the main meals for 21 days of HDT- bedrest
| Study group | Role | What they receive |
|---|---|---|
| Potassium Bicarbonate | Active comparator | Not described Receives: Dietary Supplement: Potassium Bicarbonate |
| Control | No intervention | Not described |
What is being measured
The primary outcome is the main question the study is designed to answer.
The reduction of the immobilisation induced bone loss by supplementing an alkaline salt (potassium bicarbonate)
Measured: 21 days of HDT- Bedrest
Secondary outcomes (6)
Influence of KHCO3 on bone mass, bone mineral density and bone strength
Measured: 21 days of HDT- Bedrest
Determination of effects of KHCO3 on muscle strength, muscle power and muscle volume
Measured: 21 days of HDT- Bedrest
Determine the effects of KHCO3 on body composition and body weight
Measured: 21 days of HDT- Bedrest
Determine the effects of KHCO3 on the cardiovascular system
Measured: 21 days of HDT- Bedrest
Determine the effects of KHCO3 on the neuro- vestibular system
Measured: 21 days of HDT- Bedrest
Determination of effects of KHCO3 on protein and muscle turnover
Measured: 21 days of HDT- Bedrest
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Jan 2012 (estimated)
- Study startFeb 2010
- Primary completionOct 2010
- Study completionOct 2010
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Bone Diseases, MetabolicStudies 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 N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 8 participants (actual)
Sponsor and investigators
- Lead sponsor
- DLR German Aerospace Center
- Sponsor type
- University, hospital or other
- Collaborators
- University of Trieste, University of Aarhus, European Space Agency
- Responsible party
- Sponsor
- Investigators
- Francisca May, Dr., Principal investigator, German Aerospace Centre, Institute of Aerospace Medicine (DLR)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01509456
- Sponsor's protocol ID
- AO-2004-068 (MAP)
- Acronym
- NUC
- Status last verified
- Feb 2017
- First submitted
- 4 Jul 2011
- Last updated
- 1 Mar 2017
- Results posted
- No
- Data monitoring committee
- No
Publications
Frings-Meuthen P, Bernhardt G, Buehlmeier J, Baecker N, May F, Heer M. The negative effect of unloading exceeds the bone-sparing effect of alkaline supplementation: a bed rest study. Osteoporos Int. 2019 Feb;30(2):431-439. doi: 10.1007/s00198-018-4703-6. Epub 2018 Sep 25.
PubMed 30255228
Study at a glance
From the registry record, last updated by the sponsor on 1 Mar 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Potassium Bicarbonate on Bone and the Immune System During 21 Days of 6° Head- Down- Tilt Bedrest (HDT- Bedrest)
- ClinicalTrials.gov ID
- NCT01509456
- Acronym / sponsor ID
- NUC / AO-2004-068 (MAP)
- Conditions
- Bone Diseases, Metabolic, Acid-Base Imbalance, Muscular Atrophy, Sprains and Strains, Protein Metabolism, Body Weight Changes
- Keywords
- bone metabolism, potassium bicarbonate, alkaline salt, acid base balance, bed rest
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 8 participants (actual)
- Lead sponsor
- DLR German Aerospace CenterUniversity, hospital or other
- Collaborators
- University of Trieste, University of Aarhus, European Space Agency
- Study start
- Feb 2010
- Primary completion
- Oct 2010 (actual)
- Study completion
- Oct 2010 (actual)
- First posted
- 13 Jan 2012 (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.
Mainly due to the absence of gravitational forces in weightlessness, astronauts suffer from an increased bone loss- negatively affecting health and vitality during a mission. The development of effective countermeasures to this loss includes many different aspects like sports but also nutrition.
Alkaline salts, abundant in fruits and vegetables, have shown to have positive effects on markers of bone turnover of postmenopausal women but also men and younger adults. With the current study the effects of a potassium bicarbonate supplementation added to a standardised, strictly controlled, definite diet of healthy, young men, should be verified within 21 days of 6°- HDT- Bedrest- the gold standard of simulating weightlessness within earthbound conditions.
Detailed description
Astronauts in space suffer from an increased bone loss which is mainly related to the absence of gravitational forces. This increased bone reduction is accompanied by an higher concentration of calcium in urine and in this respect enhancing the risk of renal stones. Due to the fact, that bones´ regeneration does not occur rapidly even after returning to earth, astronauts face an increased risk of osteoporosis.
Nutritional factors such as a deficient intake of calcium, energy and fluid and the abundant intake of table salt exhibit additional negative effects on bone. Results of several studies consistently show the negative effects of acids on bone (increased bone loss). With respect to space missions of longer duration one big challenge is the development of countermeasures for the negative consequences of weightlessness on bone.
As not all needed experiments for the development of countermeasures can be conducted in space, simulation models of weightlessness such as 6° Head- Down- Tilt- Bedrest (HDT- Bedrest) have been implemented on earth, miming some physiological conditions of weightlessness such as unloading and immobilisation of the lower parts of the body and the fluid shift.
Alkaline salts, such as potassium bicarbonate (KHCO3), demonstrate positive effects on bone when being supplemented to postmenopausal women. Apart from the positive effects on markers of bone turnover, calcium concentration in urine could be reduced. Thus, the main aim of the present study was to reduce the immobilization induced bone resorption through an alkalizing effect of the alkaline salt KHCO3's supplementation during Head- Down- Tilt- Bedrest (HDT- Bedrest)-a leading simulation model of weightlessness.
The crossover designed study consisted of two parts of equal length (36 days)- 7 days of adaptation, 21 days of HDT- Bedrest, 6 days recovery and 2 days of long- term follow- up. Both study parts only differed in the HDT- period, where one group of the 8 healthy, young, male participating subjects was supplemented with 90 mmol KHCO3 daily (3 times a day 30 mmol KHCO3 diluted in 200 ml tab water, supplemented together with the main meals), while the other group only received 200 ml of tab water without any supplementation (Control group).
The measurements of bone formation markers as well as bone resorption markers in blood and urine supply insight into the influences of the supplementation on bone metabolism while blood gas analysis together with the pH- values of the 24h- urine point out the alkalising effects of KHCO3. Further physiological systems like protein and muscle metabolism, body weight and body composition, circulation and the neuro- vestibular system are simultaneously under investigation.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Potassium Bicarbonate | Active comparator | Dietary Supplement: Potassium Bicarbonate |
| Control | No intervention | – |
Who may qualify
- Ages
- 20 to 45 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (11 listed)
- healthy male subjects
- age: 20- 45
- weight 65- 85 kg
- height: 158- 190 cm
- BMI 20- 26 kg/m2
Key exclusion criteria (30 listed)
- drugs- and alcohol abuse
- antiinflammatory drugs taken during the study
- vegetarianism, veganism
- migraine
- psychical illness in the past
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 Bicarbonate90 mmol daily, effervescent tablets 30 mmol diluted in 200 ml tab water supplemented three times a day together with the main meals for 21 days of HDT- bedrest | Dietary supplement | Potassium Bicarbonate |
Primary outcome
The reduction of the immobilisation induced bone loss by supplementing an alkaline salt (potassium bicarbonate)
Time frame: 21 days of HDT- Bedrest
6 secondary outcomes
Influence of KHCO3 on bone mass, bone mineral density and bone strength
Time frame: 21 days of HDT- Bedrest
Determination of effects of KHCO3 on muscle strength, muscle power and muscle volume
Time frame: 21 days of HDT- Bedrest
Determine the effects of KHCO3 on body composition and body weight
Time frame: 21 days of HDT- Bedrest
Determine the effects of KHCO3 on the cardiovascular system
Time frame: 21 days of HDT- Bedrest
Determine the effects of KHCO3 on the neuro- vestibular system
Time frame: 21 days of HDT- Bedrest
Determination of effects of KHCO3 on protein and muscle turnover
Time frame: 21 days of HDT- Bedrest
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Mar 2017.
- Derived from this study: PubMed 30255228Frings-Meuthen P, Bernhardt G, Buehlmeier J, Baecker N, May F, Heer M. The negative effect of unloading exceeds the bone-sparing effect of alkaline supplementation: a bed rest study. Osteoporos Int. 2019 Feb;30(2):431-439. doi: 10.1007/s00198-018-4703-6. Epub 2018 Sep 25.
Related trials for Bone Diseases, Metabolic
RecruitingPhase 1/2
A First-in-human Study of KK8123 in Adults With X-linked Hypophosphatemia
X-linked Hypophosphatemia
Recruiting
Metabolic Health, Bones and Nuts During Weight Loss in Adults
Weight Loss, Bone Density
RecruitingObservational study
Defining the Natural History of Squamous Cell Carcinoma in Fanconi Anemia
Fanconi Anemia, Inherited Bone Marrow Failure Syndrome
RecruitingObservational study
Natural History Study to Determine Drug Metabolism Phenotype and Appropriate Germline Source DNA in Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplant
Leukemia, Lymphoma
Not yet recruitingPhase 2
Melatonin in Posterior Mandible Extraction Socket
Bone Loss
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.
Francisca May, Dr. principal investigator
German Aerospace Centre, Institute of Aerospace Medicine (DLR)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Potassium Bicarbonate in people with Bone Diseases, Metabolic and Acid-Base Imbalance, run by DLR German Aerospace Center at 1 site in Germany.
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 30 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: finished, as of the sponsor's last update on 1 Mar 2017. 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 Germany. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
The reduction of the immobilisation induced bone loss by supplementing an alkaline salt (potassium bicarbonate) (time frame: 21 days of HDT- Bedrest). 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 NCT01509456, which also lists 1 linked publication.
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 1 Mar 2017.