The potential impact of new diagnostic criteria on the frequency of gestational diabetes mellitus in Sweden.

The International Association of Diabetes and Pregnancy Study Groups (IADPSG) has suggested new diagnostic criteria for gestational diabetes mellitus. Many centers in Europe still use the World Health Organization (WHO) criteria. In southern Sweden we use the 2-h threshold of the European Association for the Study of Diabetes criteria based on universal screening with a 75-g oral glucose tolerance test. We have retrospectively scrutinized oral glucose tolerance tests in a subset of 174 women included in a previous study, diagnosed with gestational diabetes mellitus 1996-1999. A complete repeat oral glucose tolerance test was performed directly after diagnosis in 120 women. When applying the current Swedish criteria, and the IADPSG and the WHO criteria to the material, gestational diabetes mellitus was confirmed in 67% (80/120), 84% (101/120), and 80% (96/120), respectively. Hence, 26% (101/80) more women were identified by the IADPSG criteria and 20% (96/80) more women by the WHO criteria, compared with the criteria presently in use

HbA1c as a predictor of diabetes after gestational diabetes mellitus

Aim We wanted to investigate third-trimester HbA1c as a predictor of diabetes after gestational diabetes mellitus (GDM). Methods Women with GDM were followed up prospectively for five years from pregnancy to detect the development of diabetes. The ability of HbA1c to predict diabetes was evaluated with receiver-operating characteristic (ROC) curves and logistic regression analysis. Results By five years, 73 of 196 women had been diagnosed with diabetes. An optimal cut-off point for HbA1c of 36 mmol/mol (5.4%) could predict diabetes with 45% sensitivity and 92% specificity. For HbA1c ≥39 mmol/mol (≥5.7%), sensitivity, specificity, and positive predictive value were 30%, 97%, and 91%, respectively. In logistic regression analysis, adjusting for the diagnostic glucose concentration during pregnancy, HbA1c levels in the upper quartile (≥36 mmol/mol) were associated with a 5.5-fold increased risk of diabetes. Conclusion Third-trimester HbA1c levels in the pre-diabetes range revealed women with post-partum diabetes with high specificity and high positive predictive value. HbA1c testing could be used as a strategy to select high-risk women for lifestyle interventions aimed at prevention of diabetes starting during pregnancy. The results should encourage further validation in other populations using new diagnostic criteria for GDM

Role of HbA1c in post-partum screening of women with gestational diabetes mellitus

Aim: To compare the performance of HbA1c with established glucose criteria during an oral glucose tolerance test (OGTT) and to assess HbA1c as a screening test for undiagnosed diabetes and pre-diabetes after gestational diabetes mellitus (GDM). Methods: Glucose homeostasis was re-evaluated 1–5 years after delivery in 140 women with previous GDM, by means of OGTT and simultaneous HbA1c measurement. Glucose tolerance was defined according to World Health Organisation criteria. HbA1c ≥6.5% (≥48 mmol/mol) was used for diabetes diagnosis and HbA1c ≥5.7% (≥39 mmol/mol) to define abnormal glucose homeostasis. Results: HbA1c had low sensitivity (14.3%) and high specificity (99.1%) in diabetes diagnosis. Sensitivity and specificity of HbA1c to detect abnormal glucose tolerance were 29.5% and 95.2%, respectively. The consistency in classifying abnormal glucose tolerance between HbA1c and OGTT criteria was 59% (κ = 0.227) and the area under the receiver operating characteristic curve was 0.708. The combined use of HbA1c and fasting glucose criteria showed similar performance to that of fasting glucose criteria alone. The latter identified 63% of the women with pre-diabetes or diabetes in the study cohort. However, by lowering the cut-point of HbA1c to ≥5.0% (≥31 mmol/mol), an additional proportion (27%) with isolated post-glucose load hyperglycaemia was identified. Conclusion: Proposed thresholds of HbA1c had low diagnostic sensitivity. Combined with a fasting glucose test, the performance was no better than with using a fasting glucose test alone. Combining a fasting glucose test with a lower HbA1c cut-point may be an alternative approach for selection of women for an OGTT

Pore Spanning Lipid Bilayers on Mesoporous Silica Having Varying Pore Size

Synthetic lipid bilayers have similar properties as cell membranes and have been shown to be of great use in the development of novel biomimicry devices. In this study, lipid bilayer formation on mesoporous silica of varying pore size, 2, 4, and 6 nm, has been investigated using quartz crystal microbalance with dissipation monitoring (QCM-D), fluorescent recovery after photo bleaching (FRAP), and atomic force microscopy (AFM). The results show that pore-spanning lipid bilayers were successfully formed regardless of pore size. However, the mechanism of the bilayer formation was dependent on the pore size, and lower surface coverages of adsorbed lipid vesicles were required on the surface having the smallest pores. A similar trend was observed for the lateral diffusion coefficient (D) of fluorescently labeled lipid molecules in the membrane, which was lowest on the surface having the smallest pores and increased with the pore size. All of the pore size dependent observations are suggested to be due to the hydrophilicity of the surface, which decreases with increased pore size

Pore spanning lipid bilayers on mesoporous silica having varying pore size

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Pore spanning lipid bilayers on mesoporous silica having varying pore size

Synthetic lipid bilayers have similar properties as cell membranes and have been shown to be of great use in the development of novel biomimicry devices. In this study, lipid bilayer formation on mesoporous silica of varying pore size, 2, 4, and 6 nm, has been investigated using quartz crystal microbalance with dissipation monitoring (QCM-D), fluorescent recovery after photo bleaching (FRAP), and atomic force microscopy (AFM). The results show that pore-spanning lipid bilayers were successfully formed regardless of pore size. However, the mechanism of the bilayer formation was dependent on the pore size, and lower surface coverages of adsorbed lipid vesicles were required on the surface having the smallest pores. A similar trend was observed for the lateral diffusion coefficient (D) of fluorescently labeled lipid molecules in the membrane, which was lowest on the surface having the smallest pores and increased with the pore size. All of the pore size dependent observations are suggested to be due to the hydrophilicity of the surface, which decreases with increased pore size