Changes in Acid Base Status During High Salt Intake (SL8)

August 1, 2012 updated by: DLR German Aerospace Center

The study aimed to examine the effects of an alkalinisation of a NaCl (sodium chloride, salt)-rich diet on acid base status, bone metabolism, protein turnover and other influenced physiological systems. Due to increased urinary calcium excretion and bone resorption a high NaCl-intake is considered as a risk factor for osteoporosis. On the contrary an alkaline diet is known to have a beneficial influence on bone metabolism. Therefore the investigators hypothesized that an alkaline diet can reduce NaCl-induced bone resorption.

8 healthy male volunteers took part in a stationary study carried out in the metabolic ward of the German Aerospace Center. The study consisted of 2 campaigns, each lasting 16 days. Both campaigns were divided into 5 days of adaptation, 10 days of intervention and 1.5 days of stationary recovery. During the intervention period the volunteers diet was NaCl-rich (7.7 mmol Na/kg body weight/day) and supplemented in one campaign by 90 mmol potassium bicarbonate (KHCO3) in a randomized cross-over design. The other campaign served as control.

Bone metabolism was studied by bone formation markers in the fasting morning blood and 24h-urinary bone resorption markers. Acid base status was assessed by blood gas analyses in the fasted and the postprandial state as well as urinary markers. Protein turnover was studied with stable isotopes. Further physiological systems like energy metabolism and the cardiovascular system are also under investigation.

Study Overview

Study Type

Interventional

Enrollment (Actual)

8

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Cologne, Germany, 51147
        • German Aerospace Center (DLR)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

19 years to 35 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • healthy males
  • 19 - 35 years
  • 65 - 85kg
  • 170 - 190 cm
  • successfully completed psychological and medical screening

Exclusion Criteria:

  • athletes
  • smoking
  • drug- or alcohol abuse
  • hyperlipidemia
  • renal diseases
  • obesity
  • anemia
  • bone diseases
  • diabetes
  • rheumatism
  • blood donation within three month prior to study start
  • participation in another clinical investigation three month prior to study start

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Campaign 1
7.7 mmol Na/kgBW/d + 90 mmol KHCO3
7.7 mmol Na/kgBW/d
Experimental: Campaign 2
7.7 mmol Na/kgBW/d + 90 mmol KHCO3
7.7 mmol Na/kgBW/d

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Change in daily urinary C- and N-terminal bone collagen telopeptides (mmol/d)
Time Frame: Daily for a duration of 16 days
Daily for a duration of 16 days

Secondary Outcome Measures

Outcome Measure
Time Frame
Serum concentration of bone specific alkaline phosphatase (microg/L)
Time Frame: Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing the intervention
Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing the intervention
Daily Nitrogen balance (g/d)
Time Frame: Daily for a duration of 16 days
Daily for a duration of 16 days
Free cortisol excretion in 24h urine (microg/d)
Time Frame: Baseline, after 3, 6, 10 days of intervention
Baseline, after 3, 6, 10 days of intervention
Phenylalanine hydroxylation (micromol/min)
Time Frame: Baseline, end of intervention
Baseline, end of intervention
Systolic blood pressure (bpm)
Time Frame: Daily for a duration of 16 days
Daily for a duration of 16 days
24h urinary net acid excretion (mEq/d)
Time Frame: Baseline, end of intervention
Baseline, end of intervention
Serum concentration of N-terminal propeptide Type I (mmol/L)
Time Frame: Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing intervention
Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing intervention
Free cortisone excretion in 24h urine (microg/d)
Time Frame: Baseline, after 3, 6, 10 days of intervention
Baseline, after 3, 6, 10 days of intervention
Protein synthesis (micromol/min)
Time Frame: Baseline, end of intervention
Baseline, end of intervention
Protein degradation (micromol/min)
Time Frame: Baseline, end of intervention
Baseline, end of intervention
Diastolic blood pressure (bpm)
Time Frame: Daily for a duration of 16 days
Daily for a duration of 16 days
Capillary pH
Time Frame: Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing intervention
Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing intervention
Capillary HCO3- Concentration (mmol/L)
Time Frame: Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing intervention
Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing intervention
Capillary Base excess (mmol/L)
Time Frame: Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing intervention
Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing intervention
Capillary pCO2 (mmHg)
Time Frame: Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing intervention
Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing intervention
Capillary pO2 (mmHg)
Time Frame: Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing intervention
Baseline, after 3, 6, 8, 10 days of intervention, 2 days after finishing intervention

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

July 1, 2007

Study Completion (Actual)

August 1, 2007

Study Registration Dates

First Submitted

July 23, 2012

First Submitted That Met QC Criteria

August 1, 2012

First Posted (Estimate)

August 2, 2012

Study Record Updates

Last Update Posted (Estimate)

August 2, 2012

Last Update Submitted That Met QC Criteria

August 1, 2012

Last Verified

July 1, 2012

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • DLR Salty Life 8 Study

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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