Comparison of pre-analytical properties of blood collection systems for the diagnosis of diabetes mellitus.
Author(s): Flindt J, Radziewitz M, Müller A, Harnack S, Schwarz A
Publication: Pract Lab Med, 2026, Vol. 50, Page e00534
PubMed ID: 42094914 PubMed Review Paper? No
Purpose of Paper
This paper compared glucose levels in case-matched sodium fluoride citrate plasma, lithium heparin plasma and serum specimens and retrospectively compared glucose levels in unmatched specimens collected before and after a switch from sodium fluoride to sodium fluoride citrate tubes. Prior to serum/plasma separation, sodium fluoride citrate blood was stored at room temperature for up to 10 min, lithium heparin blood was stored at room temperature or at 4°C for up to 10 min, and the serum tube was stored at room temperature for up to 30 min.
Conclusion of Paper
Compared to the lithium heparin plasma that was stored on ice, glucose levels were higher in sodium fluoride citrate plasma (5.30 versus 5.14 mmol/L, P<0.001) and lithium heparin plasma stored at room temperature (5.20 versus 5.14, P<0.001), and lower in serum (4.99 versus 5.14 mmol/L, P<0.001). Analysis of blood specimens collected before and after the laboratory switched from sodium fluoride to sodium fluoride citrate tubes showed an average increase of 105% in glucose levels. There was a concurrent increase from 26.0 % to 42.9 % in the percentage of patients classified as having impaired fasting plasma glucose (glucose ≥5.6 mmol/L to 6.99 mmol/L) and an increase from 23.5 % to 32.3% in those classified with impaired glucose tolerance (glucose >7.0mmol/L).
Studies
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Study Purpose
This study compared glucose levels in case-matched sodium fluoride citrate plasma, lithium heparin plasma and serum specimens and retrospectively in unmatched specimens collected before and after a switch from sodium fluoride to sodium fluoride citrate tubes. Blood was collected from forty-five healthy volunteers (16 men and 29 women, aged 22-59 years) into lithium heparin, sodium fluoride citrate, and serum tubes. Blood was stored in serum tubes at room temperature for up to 30 min, aliquots of lithium heparin blood were stored in an ice-water slurry for up to 10 min, and the remaining lithium heparin blood specimens and the sodium fluoride citrate blood were stored at room temperature for up to 10 min. Following storage, blood was centrifuged at 2,900 g for 10 min and plasma/serum were stored at -20°C for ≤ 50 days. Glucose levels were quantified in plasma/serum using a Cobas 8000 c701 analyzer. Additionally, the authors compared glucose levels in 91,146 specimens collected before and 88,018 specimens collected after their laboratory switched from sodium fluoride to sodium fluoride citrate tubes.
Summary of Findings:
Compared to the lithium heparin plasma that was stored on ice, glucose levels were higher in sodium fluoride citrate plasma (5.30 versus 5.14 mmol/L, P<0.001) and lithium heparin plasma stored at room temperature (5.20 versus 5.14, P<0.001), and lower in serum (4.99 versus 5.14 mmol/L, P<0.001). Analysis of blood specimens collected before and after the laboratory switched from sodium fluoride to sodium fluoride citrate tubes showed an average increase of 105% in glucose levels. There was a concurrent increase from 26.0 % to 42.9 % in the percentage of patients classified as having impaired fasting plasma glucose (glucose ≥5.6 mmol/L to 6.99 mmol/L) and an increase from 23.5 % to 32.3% in those classified with impaired glucose tolerance (glucose >7.0 mmol/L).
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Normal
- Not specified
Platform:
Analyte Technology Platform Carbohydrate Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Acquisition Type of collection container/solution Serum tube
Lithium heparin tube
Sodium fluoride citrate tube
Sodium fluoride tube
Storage Storage temperature On ice
Room temperature
Biospecimen Acquisition Anticoagulant Lithium heparin
Sodium fluoride
Sodium fluoride/citrate
None