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

This study has been completed.
Sponsor:
Collaborators:
Charite University, Berlin, Germany
University of Erlangen-Nürnberg
Information provided by (Responsible Party):
DLR German Aerospace Center
ClinicalTrials.gov Identifier:
NCT01655953
First received: July 23, 2012
Last updated: August 1, 2012
Last verified: July 2012
  Purpose

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.


Condition Intervention
Low Grade Metabolic Acidosis
Dietary Supplement: High NaCl + KHCO3
Other: Control: high NaCl

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Basic Science

Resource links provided by NLM:


Further study details as provided by DLR German Aerospace Center:

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

Secondary Outcome Measures:
  • 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 ]
  • Daily Nitrogen balance (g/d) [ Time Frame: 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 ]
  • Phenylalanine hydroxylation (micromol/min) [ Time Frame: Baseline, end of intervention ]
  • Systolic blood pressure (bpm) [ Time Frame: Daily for a duration of 16 days ]
  • 24h urinary net acid excretion (mEq/d) [ Time Frame: 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 ]
  • Free cortisone excretion in 24h urine (microg/d) [ Time Frame: Baseline, after 3, 6, 10 days of intervention ]
  • Protein synthesis (micromol/min) [ Time Frame: Baseline, end of intervention ]
  • Protein degradation (micromol/min) [ Time Frame: Baseline, end of intervention ]
  • Diastolic blood pressure (bpm) [ Time Frame: 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 ]
  • Capillary HCO3- Concentration (mmol/L) [ Time Frame: 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 ]
  • Capillary pCO2 (mmHg) [ Time Frame: 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 ]

Enrollment: 8
Study Start Date: July 2007
Study Completion Date: August 2007
Arms Assigned Interventions
Experimental: Campaign 1 Dietary Supplement: High NaCl + KHCO3
7.7 mmol Na/kgBW/d + 90 mmol KHCO3
Other: Control: high NaCl
7.7 mmol Na/kgBW/d
Experimental: Campaign 2 Dietary Supplement: High NaCl + KHCO3
7.7 mmol Na/kgBW/d + 90 mmol KHCO3
Other: Control: high NaCl
7.7 mmol Na/kgBW/d

  Eligibility

Ages Eligible for Study:   19 Years to 35 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

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
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01655953

Locations
Germany
German Aerospace Center (DLR)
Cologne, Germany, 51147
Sponsors and Collaborators
DLR German Aerospace Center
Charite University, Berlin, Germany
University of Erlangen-Nürnberg
  More Information

Responsible Party: DLR German Aerospace Center
ClinicalTrials.gov Identifier: NCT01655953     History of Changes
Other Study ID Numbers: DLR Salty Life 8 Study
Study First Received: July 23, 2012
Last Updated: August 1, 2012

Additional relevant MeSH terms:
Acidosis
Acid-Base Imbalance
Metabolic Diseases

ClinicalTrials.gov processed this record on April 28, 2017