Impact of blood cell counts and volumes on glucose concentration in uncentrifuged serum and lithium-heparin blood tubes.
Author(s): Lippi G, Salvagno GL, Lampus S, Danese E, Gelati M, Bovo C, Montagnana M, Simundic AM
Publication: Clin Chem Lab Med, 2018, Vol. , Page
PubMed ID: 29935113 PubMed Review Paper? No
Purpose of Paper
This paper investigated the effects of delayed blood processing on glucose concentration in lithium heparin plasma and serum and the impact of blood cell counts on the changes observed.
Conclusion of Paper
The glucose concentration was significantly higher in lithium heparin plasma than in serum when centrifuged 15 min after collection. Glucose levels in lithium heparin plasma and serum declined with increased pre-centrifugation storage but the rate of decline was larger in plasma than serum. The red blood cell (RBC), white blood cell (WBC), neutrophil, and monocyte counts were associated with the decrease in glucose concentration by multivariate analysis and significant differences in glucose concentrations were observed between tertiles for WBC, RBC, neutrophil, and monocyte counts.
Studies
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Study Purpose
This study investigated the effects of delayed blood processing on glucose concentration in lithium heparin plasma and serum and the impact of blood cell counts on the changes observed. Blood was collected using 19-gauge needles by the same phlebotomist from 30 healthy volunteers into three lithium heparin tubes with gel separator and three serum tubes with clot activator and serum separator. The draw order shifted between subjects. One tube of each type was centrifuged at 1300 x g for 15 min after storage vertically for 15 min, 1 h, or 2 h at room temperature. Glucose was measured in serum and plasma immediately after separation using the hexokinase assay on a Roche Cobas c702 analyzer. A complete blood count was performed in lithium heparin plasma separated 15 min after collection using a Sysmex XN hematological analyzer.
Summary of Findings:
The glucose concentration was significantly higher in lithium heparin plasma than in serum when centrifuged 15 min after collection (4.72 mmol/ L versus 4.66 mmol/L, P=0.012). Glucose levels in lithium heparin plasma declined by 7% when blood was stored pre-centrifugation for 1 h versus 15 min (P<0.001) and then another 8% when stored for 2 h rather than 1 h (P<.001). Similarly, glucose levels in serum declined with increasing centrifugation delays (4% for 1 h versus 15 min, P<0.001 and 3% for 2 h versus 1 h, P<0.001). The rate of decline of glucose levels was higher in plasma than serum (0.33 mmol/L/h versus 0.24 mmol/L/h, P<0.001). In univariate analysis, the decrease in glucose concentration with delayed centrifugation was modestly higher in men than women (r=0.62, P<0.001) and was modestly associated with high RBC counts (r=0.54, P=0.002), hematocrit (r=0.48, P=0.007), WBC counts (r=0.53, P=0.003), monocyte counts (r=0.63, P<0.001), and neutrophil counts (r=0.54, P=0.002), but in multivariate analysis only the RBC, WBC, neutrophil, and monocyte counts were associated with the decrease in glucose concentration (P=0.013, P=0.049, P=0.022, and P=0.008; respectively). Finally, significant differences in glucose concentrations across hematology tertiles were observed for WBC (P=0.025 in plasma and P=0.013 in serum), RBC (P=0.019 in plasma and P=0.009 in serum), neutrophils (P=0.009 in plasma and P=0.016 in serum), and monocytes (P<0.001 in plasma and P=0.009 in serum).
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Normal
Platform:
Analyte Technology Platform Cell count/volume Hematology/ auto analyzer Carbohydrate Colorimetric assay Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Centrifugation Centrifugation delays investigated
Biospecimen Aliquots and Components Biospecimen components Multiple CBC ranges and tertiles
Storage Time at room temperature 15 min
1 h
2 h
Biospecimen Aliquots and Components Blood and blood products Serum
Plasma