When to collect blood specimens: midmorning vs fasting samples.
Author(s): Leppänen E, Dugué B
Publication: Clin Chem, 1998, Vol. 44, Page 2537-42
PubMed ID: 9836723 PubMed Review Paper? No
Purpose of Paper
Conclusion of Paper
Studies
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Study Purpose
The purpose of this study was to determine the effects of collecting fasting blood specimens at 8:00 am versus collecting blood after breakfast at 9:30 am or 11:00 am on 32 common hematology and clinical chemistry analytes. Three specimens (one at each time point) were collected from each patient. Complete blood counts, thromboplastin time, and erythrocyte sedimentation rates were analyzed in fresh specimens. Serum was separated and frozen at -20 degrees C for 2-5 days prior to analysis of clinical chemistry analytes.
Summary of Findings:
22 of the 32 analytes examined showed statistically significant differences between specimens obtained from fasting individuals and those obtained after the subjects had breakfast. Clinically significant changes were observed for 17 of the analytes in some individuals. The direction or degree of changes observed for many analytes were different between inpatients and outpatients. Analytes showing changes in the opposite direction between inpatients and outpatients included sodium, creatinine, aspartate aminotransferase, gamma-glutamyltransferase, alanine aminotransferase, cholesterol, and free thyroxine.
Biospecimens
Preservative Types
- None (Fresh)
- Frozen
Diagnoses:
- Not specified
- Normal
Platform:
Analyte Technology Platform Morphology Hematology/ auto analyzer Cell count/volume Hematology/ auto analyzer Protein Hematology/ auto analyzer Steroid Clinical chemistry/auto analyzer Lipid Clinical chemistry/auto analyzer Electrolyte/Metal Clinical chemistry/auto analyzer Small molecule Clinical chemistry/auto analyzer Carbohydrate Clinical chemistry/auto analyzer Glycoprotein Clinical chemistry/auto analyzer Protein Clinical chemistry/auto analyzer Peptide Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Preservation Type of fixation/preservation Frozen
None (fresh)
Biospecimen Aliquots and Components Blood and blood products Serum
Whole blood
Biospecimen Acquisition Time of biospecimen collection 8:00 am (fasting)
9:30 am (after breakfast)
11:00 am (after breakfast)
Preaquisition Diagnosis/ patient condition Inpatient (unspecified)
Outpatient (healthy)