Will the Use of Lyophilized Citrate Tubes Lead to the Over-Diagnosis of Diabetes in Pregnancy?

Abstract

COOH losses in urine from contact with LDPE.Because of limitations of available leftover patient urine volume, analysis time, and cost, we only performed singlicate experiments, which demonstrated that the THC-COOH concentrations in the inverted, metal lid containers of urine specimens varied by −50% to +9% from their plastic-only counterparts. When averaged, a reduction of 29% was observed. Specimens collected and stored in these containers could potentially yield falsely low THC-COOH results. We caution the adoption of new specimen containers until they are investigated on all subjected analytes.

Recommended pre‐analytical plasma glucose sampling methodology may distort gestational diabetes mellitus prevalence: implications for diagnostic thresholds

“…These small studies reported GDM prevalence rates ranging from 14.4% to 20% using traditional pre-analytical plasma glucose methods, which were within the range of 9.3% to 25.5% seen in HAPO centres [15]. Using paired samples and recommended pre-analytical plasma glucose methods, these studies reported a GDM prevalence of 38.1% to 54% in the same cohorts [9,11,12]. A larger cohort study from Odense, Denmark [14] in a seemingly low-risk population, used recommended pre-analytical plasma glucose methodology and reported a GDM prevalence by FPG of 40.1%.…”

“…GDM prevalence, in our seemingly low-risk cohort of predominately Caucasian women, was 13.5%; comparable with other Australian HAPO centres (Table 3). We compare our GDM prevalence of 13.5% with small cohort studies using paired traditional and recommended pre-analytical plasma glucose methodologies [9,11,12]. These small studies reported GDM prevalence rates ranging from 14.4% to 20% using traditional pre-analytical plasma glucose methods, which were within the range of 9.3% to 25.5% seen in HAPO centres [15].…”

“…We modelled the use of recommended citrate‐buffered tubes for plasma glucose analysis using the results of Carey et al . as a basis for formulating adjustment factors. For the modelling purposes, the plasma glucose levels observed in our cohort were multiplied by adjustment factors of 1.113 (4.9/4.4) for FPG, 1.081 (8.0/7.4) for 1‐h plasma glucose and 1.061 (6.9/6.5) for 2‐h plasma glucose (Table ).…”

“…Recent small cohort studies investigating the impact of pre‐analytical plasma glucose methodology on GDM prevalence have demonstrated a 2.5–3‐fold increase in GDM prevalence when recommended methods replaced traditional pre‐analytical plasma glucose methods . However, without clinical outcome data it cannot be determined which pre‐analytical plasma glucose method is consistent with HAPO.…”

Plasma glucose sampling using lyophilized citrate tubes: impact on the diagnosis of gestational diabetes mellitus

“…Five years ago, Daly et al 1 demonstrated that the American Diabetes Association pre-analytical glucose sample handling recommendations, which included placing tubes immediately on an ice slurry, resulted in higher mean glucose concentrations and a 2.7-fold increase in the diagnosis of gestational diabetes mellitus (GDM), compared with usual hospital practices. Recently, Song et al 2 compared the prevalence of GDM in 1178 pregnant women when glucose concentrations were measured in traditional sodium fluoride (NaF)/ potassium oxalate tubes, without citrate, with the prevalence when they were measured in lyophilized citrate tubes, using multiplying factors as published by Carey et al 3 Using standard methods, the prevalence of GDM was 13.5%, and this increased to 39.2% using the citrate tubes. A closer control of glucose concentration fasting trueness, around 5.1 mmol/l, is recommended for both pre-analytical and analytical phases, as small differences in fasting plasma glucose (FPG) concentrations profoundly affect GDM prevalence.…”