Influence of Serum Sodium Levels on Bone Metabolism and Turnover in Hospitalized Patients

Study Overview
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Brief Summary
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In this study, the possible role of serum sodium concentration and its changes on bone markers in hospitalized, hyponatremic patients is determined. Therefore, it is investigated whether in hospitalized, hyponatremic patients the level of carboxy-terminal collagen crosslinks (CTX) is modified by changes in plasma sodium concentration, independently from the aetiology of hyponatremia.

Official Title
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Influence of Serum Sodium Levels on Bone Metabolism and Turnover in Hospitalized Patients - A Prospective Study (BONA-Trial)

Conditions
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Hyponatremia

Intervention / Treatment
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* Other: blood sampling


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult hospitalized patients with non-hypertonic hyponatremia: serum sodium < 130 mmol/l, serum osmolality < 300 milliosmol /kg age 18 to 99-year-old Informed consent as documented by signature Exclusion Criteria: Severe symptomatic hyponatremia in need of intensive care treatment Hypertonic hyponatremia with serum osmolality > 300 mOsm/kg End of life care (palliative treatment) End stage kidney disease (dialysis) Acute liver failure Wernicke encephalopathy Hepatic encephalopathy during last 2 months Hepato-renal syndrome Any bone disease requiring treatment in the last three years History of fragility fractures Pre-menopausal women Hypogonadism (diagnosed before hospitalization) Hyperthyroidism Steroid therapy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Hyponatremic patients<br>Patients hospitalized at the University Hospital of Basel and presenting with hyponatremia will be screened for the study | Other: blood sampling<br>* blood sampling for measurement of bone markers after a fasting period of at least 6 hours<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in carboxy-terminal collagen crosslinks (CTX) levels | CTX level (pg/ml) and its dynamic within 10 days of hospitalization | baseline blood exam on day 1 after inclusion and further blood collections at day 10 (+/-3 days) or at discharge, if discharge will be earlier | 
| Change in plasma sodium level | serum sodium levels (milliequivalents per liter (mEq/L) and its dynamic within 10 days of hospitalization | baseline blood exam on day 1 after inclusion and further blood collections at day 10 (+/-3 days) or at discharge, if discharge will be earlier | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in bone specific alkaline phosphatase (bAP) | bAP levels and their dynamic within 10 days of hospitalization | baseline blood exam on day 1 after inclusion and further blood collections at day 10 (+/-3 days) or at discharge, if discharge will be earlier | 
| Change in osteocalcin | Osteocalcin (ng/mL) levels and their dynamic within 10 days of hospitalization | baseline blood exam on day 1 after inclusion and further blood collections at day 10 (+/-3 days) or at discharge, if discharge will be earlier | 
| Change in procollagen type I N propeptide (PINP) (PINP) levels | PINP (ng/mL) levels and their dynamic within 10 days of hospitalization | baseline blood exam on day 1 after inclusion and further blood collections at day 10 (+/-3 days) or at discharge, if discharge will be earlier | 
| Change in sclerostin | Sclerostin (pg/ml) levels and their dynamic within 10 days of hospitalization | baseline blood exam on day 1 after inclusion and further blood collections at day 10 (+/-3 days) or at discharge, if discharge will be earlier | 
| Change in parathyroid hormone (PTH) | PTH (pg/ml) levels and their dynamic within 10 days of hospitalization | changes from baseline (day 1) to day 10 after inclusion in the study | 
| Change in 25-hydroxy-vitamin D3 | 25-hydroxy-vitamin D3 (ng/ml) levels and their dynamic within 10 days of hospitalization | baseline blood exam on day 1 after inclusion and further blood collections at day 10 (+/-3 days) or at discharge, if discharge will be earlier | 
| Change in calcium | Calcium (mg/dl) levels and their dynamic within 10 days of hospitalization | baseline blood exam on day 1 after inclusion and further blood collections at day 10 (+/-3 days) or at discharge, if discharge will be earlier | 
| Change in phosphate levels | Phosphate(mg/dl) levels and their dynamic within 10 days of hospitalization | baseline blood exam on day 1 after inclusion and further blood collections at day 10 (+/-3 days) or at discharge, if discharge will be earlier | 
| Numbers of falls | telephone interview will be performed to collect data about occurrence and numbers of falls within 30 days after enrolment | numbers of falls within 30 days after enrolment | 
| Numbers of fractures | telephone interview will be performed to collect data about occurrence and numbers of fractures within 30 days after enrolment | Numbers of fractures within 30 days after inclusion in the study | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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electrolyte disorder, Bone Metabolism, Sodium Levels