Changes in Serum Creatinine Levels Can Help Distinguish Hypovolemic From Euvolemic Hyponatremia

Study Overview
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Brief Summary
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Retrospective study that analyzes the changes in serum creatinine as a tool to correctly classify the volemic status volemic status (euvolemia vs hypovolemia) of the patients with hyponatremia.

Detailed Description
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This study evaluates the usefulness of the changes in serum creatinine in differentiating between euvolemia and hypovolemia in hyponatremic patients. Changes in serum creatinine were retrospectively analyzed . The latter was calculated subtracting the serum creatinine value of eunatremia from that of hyponatremia, and was categorized as an increase when it was positive, or decrease/no change when it was negative or equal to zero. The percentual change in serum creatinine was also calculated. Two groups of patients were selected for the current study. First group was conformed by patients with hypovolemic hyponatremia, and second group by patients with euvolemic hyponatremia. Data from eunatremia as well as the hyponatremic episode were collected. Both groups were matched in Receiver operating characteristic curve analyzes where both arithmetical and percentual changes in serum creatinine were assessed and cut-off points were selected for an additional Odd Ratio analysis.

Official Title
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Changes in Serum Creatinine Levels Can Help Distinguish Hypovolemic From Euvolemic Hyponatremia

Conditions
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Hyponatremia, Hypovolemia, SIADH

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with hypovolemic hyponatremia secondary to any cause Patients with euvolemic hyponatremia caused by Syndrome of inappropriate antidiuresis Complete clinical volemia assessment during hyponatremia. Presence of serum creatinine measured in eunatremia as well as in hyponatremic episodes. Exclusion Criteria: Pregnants. Patients with a prior history of diabetes, advanced chronic kidney disease (glomerular filtrate rate below 30 ml/min), cirrhosis, or heart failure were excluded. Patients with hypervolemic hyponatremia.

Ages Eligible for Study
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Minimum Age: 18 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 |
| --- | --- |
| Hypovolemic hyponatremia<br>Patients with any cause of hypovolemic hyponatremia were included. | |
| Euvolemic hyponatremia<br>Only patients with euvolemic hyponatremia secondary to Syndrome of inappropriate antidiuresis were included. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnostic Accuracy of the changes in serum creatinine for volemic classification of hyponatremia | Area under the curve from the Receiver operating characteristic curve analysis were calculated for the changes in serum creatinine. Probabilities of each evaluated tool (arithmetic and percentual change in serum creatinine) to correctly classified the volemic status of the hyponatremic patients were calculated. | 4 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ratio of Correct volemic classification of hyponatremia when Changes in Serum creatinine were used. | Ratio of patients who were correctly classified according to volemic status with different cut-off points obtained from the Receiver operating characteristic curve analyzes. Sensitivity, Specificity, Positive and Negative predictive values were also calculated. | 4 months | 
| Diagnostic Accuracy of Urine sodium for volemic classification of hyponatremia | Area under the curve from the Receiver operating characteristic curve analysis were calculated for the urine sodium y patients with hyponatremia. Sensitivity, specificity, and Positive and Negative predictive values were calculated. | 4 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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hyponatremia diagnosis, serum creatinine;, hypovolemic hyponatremia, euvolemic hyponatremia, SIAD