Comparison of Venous and Capillary Sampling in Oral Glucose Testing for the Diagnosis of Gestational Diabetes Mellitus: A Diagnostic Accuracy Cross-Sectional Study Using Accu-Chek Inform II

Abstract

Gestational diabetes mellitus (GDM) is a common complication with negative impacts on mother and child. The primary aim of this study was to examine whether plasma glucose cutoffs for GDM diagnosis based on venous sampling can be replaced by cutoffs based on capillary sampling. A prospective cross-sectional study was performed at an antenatal care clinic including 175 pregnant women undergoing an oral glucose tolerance test (OGTT). Duplicate samples were collected by capillary and venous puncture while fasting and 1 h and 2 h after an OGTT. Both samples were analyzed on Accu-Chek Inform II. The cutoffs for a GDM diagnosis using capillary samples were corrected from 5.1 to 5.3 mmol/L for the fasting sample, from 10.0 to 11.1 mmol/L for the 1 h sample, and from 8.5 to 9.4 mmol/L for the 2-h sample using half of the dataset. Applying these cutoffs to the remaining dataset resulted in a sensitivity, specificity, and accuracy of 85.0%, 95.0%, and 90.3%, respectively, with a positive predictive value (PPV) of 83%, an negative predictive value (NPV) of 96%, and a positive negative likelihood ratio (LHR) of 16.4 using capillary sampling for the GDM diagnosis at fasting and 2-h after. Corrected cutoffs and capillary samples can be used for the diagnosis of GDM with maintained diagnostic accuracy using Accu-Chek Inform II.

Universal screening for early detection of chronic autoimmune, metabolic and cardiovascular diseases in the general population using capillary blood (UNISCREEN): low-risk interventional, single-centre, pilot study protocol

“…The chronic diseases investigated in this study include autoimmune type 1 diabetes and coeliac disease and the metabolic/CV diseases, or risk factors, type 2 diabetes, dysglycaemia and dyslipidaemia, all with validated markers measurable in capillary blood 24–32…”

“…The chronic diseases investigated in this study include autoimmune type 1 diabetes and coeliac disease and the metabolic/CV diseases, or risk factors, type 2 diabetes, dysglycaemia and dyslipidaemia, all with validated markers measurable in capillary blood. [24][25][26][27][28][29][30][31][32] Feasibility and acceptability have already been shown in type 1 diabetes screening using capillary blood sampling, 26 with advantages over outpatient venipuncture, particularly in children. 47 Islet autoantibody screening proved to be accurate in identifying presymptomatic stages of type 1 diabetes 45 and effective in reducing the frequency of the associated DKA at the time of clinical onset.…”

“…23 Moreover, in most cases, capillary and venous blood can be used for the same measurements, without affecting the validity of test results. Validated markers measurable in capillary blood include: islet autoantibodies for type 1 diabetes [24][25][26] and TGA autoantibodies for coeliac disease 27 ; glucose 28 and HbA1c 29 for type 2 diabetes and dysglycaemia; total, high density lipoprotein (HDL)-cholesterol, LDL-cholesterol and triglycerides 30 31 for dyslipidaemia, including in children. 32 Explanation for the choice of comparators Not applicable, as the screening intervention is equally offered to the entire study population.…”

“…GADA, IAA, IA-2A, ZnT8A and TGA are measured by luciferase immunoprecipitation system (LIPS) (or LIPS converted from radio-binding assay -RBA) assays as previously reported. [34][35][36][37][38] Extemporary measurements using capillary blood by point-of-care devices include glucose (0.6 µL, Accu-Chek Inform II), 28 HbA1c (2 µL, Cobas b 101 Roche) 29 and lipid panel, including total cholesterol and HDL-cholesterol, 30 triglycerides 31 and LDL-calculated cholesterol (19 µL, Cobas b 101 Roche). 29 Results of extemporary measurements are available in a few minutes, reported in the patient case report form (CRF), communicated and discussed by the physician in the interview with the participant.…”