A Prospective Evaluation of Point-of-Care Measurements of Maternal Glucose for the Diagnosis of Gestational Diabetes Mellitus

Clinical utility of point-of-care glucose testing in the assessment of gestational diabetes: Prospective cohort study

OBJECTIVE

To assess the clinical utility of point-of-care (POC) capillary blood glucose (CBG) testing in the assessment of gestational diabetes mellitus (GDM) during oral glucose tolerance test (OGTT).

DESIGN

Prospective cohort study.

SETTING

Antenatal clinics at King's College Hospital.

POPULATION

Women screened for GDM between March and June 2020.

METHODS

The CBG was measured using the POC StatStrip® test and the venous plasma glucose (VPG) was measured by Roche analyser (Cobas 8000 c702). GDM was diagnosed based on the 2015 National Institute for Health and Clinical Excellence (NICE) Clinical Guideline criteria. The two methods were compared statistically using Analyse-It 5.40.2.

MAIN OUTCOME MEASURES

Diagnostic sensitivity, specificity, positive and negative predictive values (PPV and NPV) for the POC StatStrip® test, compared with VPG measured by reference laboratory method.

RESULTS

A total of 230 women were included. The number and percentage of women with glucose concentrations above the GDM threshold using the POC StatStrip® test versus laboratory VPG measurement was 15 (6.5%) versus eight (3.4%) at fasting and 105 (45.6%) versus 72 (31.1%) at 2 h, respectively. The sensitivity and specificity values (and 95% CIs) for the POC StatStrip® test were 88% (52%-99%) and 97% (93%-98%) at fasting and 97% (91%-99%) and 79% (71%-84%) at 2 h, respectively. However, the specificity and the NPV for the POC StatStrip® test for concentrations of ≤5.0 mmol/L at fasting or <7.5 mmol/L at 2 h were 100%, and the sensitivity and the PPV for concentrations of >9.5 mmol/L at 2 h were 100%.

CONCLUSIONS

In our cohort the POC measurement of CBG cannot entirely replace the laboratory method for the OGTT; however, it can be used to rule out/rule in GDM for glucose concentrations of ≤5.0 mmol/L at fasting or <7.5/>9.5 mmol/L at 2 h.

Feasibility and accuracy of at-home glucose tolerance tests for cystic fibrosis related diabetes screening

BACKGROUND

Adult people living with Cystic Fibrosis (CF) undergo annual screening for CF-related diabetes. These tests represent a burden and can lead to undesirable effects resulting in low adherence. The objectives of this study were to 1) compare gold-standard in-hospital oral glucose tolerance testing (OGTT) with at-home options, and 2) evaluate acceptability of at-home options.

METHODS

A total of 34 adults living with CF undertook 3 types of OGTTs in standardized conditions within two weeks: 1) in a hospital using a 75 g glucose beverage, 2) at home with the same glucose beverage, and 3) at home using a standardized quantity of candy. Glucose levels were measured prior to the OGTT, after 1 and 2 hours. Concordance of glucose measurement, side effects and general appreciation were assessed across the three options.

RESULTS

Mean blood glucose was comparable among the three tests. Glucose tolerance categorization (normal, impaired glucose tolerance, or diabetes) was concordant with the hospital reference test in 59 % of participants for the glucose beverage and 75 % for the candies. Side effects were mild with all types of OGTTs, and 94 % of participants preferred the home options. Among the at-home OGTTs, the glucose beverage was preferred to the candy option.

CONCLUSIONS

Home-based OGTT could be an alternative to gold standard hospital-based OGTT testing, improving adherence to annual testing and reducing costs. However, the discrepancy between various OGTT testing methods could lead to diagnosis dilemma. This approach should be tested on a larger sample size.

Determinants of health literacy and its impact on glycemic control among women with gestational diabetes mellitus in a tertiary care hospital, Puducherry - A cross-sectional analytical study

BACKGROUND

Health literacy is vital during pregnancy, as maternal health knowledge and behavior have a significant impact on the health of both mother and child. Hence, this study aimed to assess the health literacy status of pregnant women diagnosed with gestational diabetes mellitus (GDM), as well as its associated factors and impact on glycemic control.

MATERIALS AND METHODS

The facility-based Cross-sectional analytical study was conducted among 200 pregnant women with GDM in a tertiary care hospital. The eligible participants were consecutively selected for the study. The study was conducted from September 2022 to March 2023. A validated semi-structured questionnaire, the Health Literacy Questionnaire (HLQ) for GDM, was used to measure health literacy status. Stata V.17 software was used for data analysis.

RESULTS

Out of 200 pregnant women with GDM, the mean (SD) age of the participants is 29.5 (±5.5) years. It was observed that 164 (82%) of the participants had adequate health literacy, whereas 36 (18%) had inadequate health literacy about Gestational Diabetes. Adequate health literacy (HL) was observed among 88.5% of women with controlled blood sugar and 55.1% of women with uncontrolled blood sugar. Results of multivariate logistic regression analysis revealed that pregnant mothers' educational status (PR: 1.8; 95% CI: 1.2-2.5) and glycemic control (PR: 1.4; 95% CI (1.2-1.7) were associated with adequate HL.

CONCLUSIONS

In conclusion, this study supports the association between adequate HL and glycemic control in pregnant women with GDM. Addressing this gap is essential for healthcare officials and planners to implement programs that promote women's HL during pregnancy, with a focus on low-educated groups.

Wearable non-invasive glucose sensors based on metallic nanomaterials

The development of wearable non-invasive glucose sensors provides a convenient technical means to monitor the glucose concentration of diabetes patients without discomfortability and risk of infection. Apart from enzymes as typical catalytic materials, the active catalytic materials of the glucose sensor are mainly composed of polymers, metals, alloys, metal compounds, and various metals that can undergo catalytic oxidation with glucose. Among them, metallic nanomaterials are the optimal materials applied in the field of wearable non-invasive glucose sensing due to good biocompatibility, large specific surface area, high catalytic activity, and strong adsorption capacity. This review summarizes the metallic nanomaterials used in wearable non-invasive glucose sensors including zero-dimensional (0D), one-dimensional (1D), and two-dimensional (2D) monometallic nanomaterials, bimetallic nanomaterials, metal oxide nanomaterials, etc. Besides, the applications of wearable non-invasive biosensors based on these metallic nanomaterials towards glucose detection are summarized in detail and the development trend of the wearable non-invasive glucose sensors based on metallic nanomaterials is also outlook.

The impact of inter-laboratory glucose bias on the diagnosis of gestational diabetes mellitus: Comparison of common automated central laboratory methods

BACKGROUND AND AIMS

The diagnosis of gestational diabetes mellitus (GDM) is based exclusively on glucose measurements, which are highly influenced by pre-analytical and analytical factors. Therefore, poor agreement across laboratories may affect the prevalence of GDM. We aimed to determine the inter-laboratory bias of glucose measurements and the impact on GDM prevalence.

MATERIAL AND METHODS

A prospective cohort study of women (n=110) referred for second-trimester GDM diagnostics using a 75 g oral glucose tolerance test. Maternal glucose was assessed from venous plasma at fasting, 1 h and 2 h. Venous blood were collected in Fluoride Citrate tubes and frozen. Samples were analyzed at five central laboratories using four different automated glucose Hexokinase methods and GDM prevalence was evaluated according to WHO2013 diagnostic criteria.

RESULTS

Maximum inter-laboratory bias was 0.19, 0.30 and 0.27 mmol/L in fasting, 1 h and 2 h samples, respectively. GDM prevalence ranged 30.0-41.1% across laboratories.

CONCLUSION

Inter-laboratory bias for mean venous glucose was low and within desirable limits. Nonetheless, the impact on GDM prevalence was considerable, which may inappropriately affect clinical practice.

Regional divergence and time trends in the prevalence of gestational diabetes mellitus: a national Danish cohort study

AIMS

To evaluate the prevalence and time trends of gestational diabetes mellitus (GDM) across the five regions of Denmark with uniform national guidelines for screening and diagnosing GDM.

METHODS

This register-based national cohort study included 287,684 births from 2013 to 2017. Trends in GDM prevalence over time and differences between the five regions were evaluated. Crude and adjusted odd ratios (ORs) for GDM were calculated including potential confounding clinical risk factors as age, BMI, educational level, marital status, parity, country of origin and assisted reproduction.

RESULTS

From 2013 to 2017, GDM prevalence in Denmark increased by 7% per year (OR 1.07, 95% CI 1.06-1.09, P < 0.001). GDM prevalence varied considerably between regions and ranged from 3.0 to 5.9% in 2017, corresponding to a maximal regional difference of 97%. In crude analyses, the risk of GDM in 2017 was significantly different in four of five regions compared to the remaining regions (OR ranging from 0.60 to 1.55), and these differences persisted after adjusting for confounding clinical risk factors (adjusted OR: 0.59-1.45).

CONCLUSION

The prevalence of GDM increased over time in all Danish regions with substantial regional divergence. Up to a 97%, difference in GDM prevalence was observed between Danish regions, which was not explained by available clinical risk factors. This occurred despite national guidelines and raises the question of whether regional variations in screening efficacy, diagnostic procedures or inequality in clinical health care access may explain the observed differences.

Adherence to medical nutrition therapy and it's challenges among antenatal women with gestational diabetes mellitus in South India- A sequential explanatory mixed-method study

BACKGROUND

Globally, one in ten pregnant women have diabetes; out of which, 90% contribute to gestational diabetes mellitus (GDM). Medical Nutrition Therapy (MNT) is the cornerstone for GDM treatment yet adherence to MNT among the masses is not adequately monitored as part of the routine antenatal services. The study aimed to estimate the proportion of adherence to MNT and determine the factors related toadherence among antenatal women with GDM. This study also explores the facilitators, barriers, and possible suggestions for improving adherence.

MATERIALS AND METHODS

This facility-based sequential explanatory mixed-method study was conducted among 341 antenatal women with GDM at, Puducherry. The study was conducted in 2021. Dietary adherence was evaluated using Perceived Dietary Adherence Questionnaire and based on the scores obtained they were selected for in-depth interviews to explore the facilitators and barriers. Collected data wereanalysed by Chi-square test using STATA version 16.

RESULTS

Out of 341 participants, the proportion of participants adherent to MNT was 135 (39.6%) with 95% CI of 34%-44%. Thepredictors for poor adherence were unemployment (PR: 0.65; 95%CI: 0.48-0.88) and good adherence was antenatal women in the 2^nd trimester (PR: 1.541; 95%CI: 1.18-2.025). Barrierstonon-adherence were financial crisis, lack of awareness ofthe need for MNT, and joint family pressure.

CONCLUSIONS

About two-thirds of antenatal women with GDM are non-adherent to MNT. Unemployment and period of gestation were found to be theirdeterminants. Appropriate action has to be implemented for improving the adherence rate.

Screening for Gestational Diabetes Mellitus in Early Pregnancy: What Is the Evidence?

The incidence of gestational diabetes mellitus (GDM) is increasing worldwide. This has a significant effect on the health of the mother and offspring. There is no doubt that screening for GDM between 24 and 28 weeks is important to reduce the risk of adverse pregnancy outcomes. However, there is no consensus about diagnosis and treatment of GDM in early pregnancy. In this narrative review on the current evidence on screening for GDM in early pregnancy, we included 37 cohort studies and eight randomized controlled trials (RCTs). Observational studies have shown that a high proportion (15–70%) of women with GDM can be detected early in pregnancy depending on the setting, criteria used and screening strategy. Data from observational studies on the potential benefit of screening and treatment of GDM in early pregnancy show conflicting results. In addition, there is substantial heterogeneity in age and BMI across the different study populations. Smaller RCTs could not show benefit but several large RCTs are ongoing. RCTs are also necessary to determine the appropriate cut-off for HbA1c in pregnancy as there is limited evidence showing that an HbA1c ≥6.5% has a low sensitivity to detect overt diabetes in early pregnancy.

Glycemic control and its associated factors among women with gestational diabetes mellitus in a tertiary care Centre, Puducherry, South India

Background:

Worldwide, one in ten pregnancies is related with diabetes; 87.6% of which are gestational diabetes mellitus (GDM). Maternal hyperglycaemia affects the successful progression of pregnancy.

Objectives:

To determine the proportion and the factors associated with poor glycaemic control among women with gestational diabetes.

Methods:

This hospital-based cross-sectional study was conducted in a tertiary care hospital, Puducherry, South India from September to October 2019. Pregnant women diagnosed as GDM and on treatment for at least one month were approached consecutively for the study. A fasting blood sugar (FBS) ≥92 mg/dl and postprandial blood sugar (PPBS) 1 hour ≥180 mg/dl or PPBS 2 hour ≥153 mg/dl were considered as poor glycaemic control.

Results:

A total of 301 women with GDM were included and the mean (SD) age was 27 (5) years. Of total, 29 (10%) reported GDM during their previous pregnancy and 95 (32%) got diagnosed before reaching the tertiary care hospital. Lifestyle modifications (77%) were the most common mode of management for GDM. Of total, 116 (38.5%; 95% CI 33%-44.3%) had poor glycaemic control. Multigravida women (46.9%) and those on pharmacological treatment for GDM had poor glycaemic control.

Conclusion:

One-third of women with GDM at a tertiary care centre had poor glycaemic control. Therefore, a novel approach to improve awareness about GDM control both among pregnant women and the medical fraternity is needed.

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

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.

Prevalence estimates of diabetes in pregnancy in a rural, sub-Saharan population

AIMS

To determine the prevalence of Hyperglycaemia first Detected in Pregnancy (HDIP) in a cohort of women from rural Gambia and compare the diagnostic ability of capillary blood glucose (CBG) sampling to identify HIP versus laboratory-based analysis of venous plasma glucose (VPG).

METHODS

Pregnant women from rural Gambia (N = 251) underwent a 75 g Oral Glucose Tolerance Test (OGTT) at 28-weeks of gestation. Gestational Diabetes Mellitus was assessed as fasting glucose concentration ≥ 5.1-6.9 mmol/L; ≥10.0 mmol/L at 1-h post load; or ≥ 8.5 mmol/L at 2-h post load and Diabetes in Pregnancy as fasting glucose > 7.0 mmol/L.

RESULTS

A total of 199 and 244 women had VPG and CBG measurements respectively, and 198 women had both. 32 women (16.1%) were diagnosed with HDIP using VPG, mostly based on fasting concentrations.

CONCLUSIONS

The prevalence of HDIP in rural Gambia was higher than anticipated, emphasising a need for maternal diabetic policy. Based on the current findings, tailored recommendations could include measuring fasting VPG alone when conducting a full OGTT is not feasible. Similarly, CBG may be of value for excluding disease and thereby limiting costly laboratory-based investigations to a select few.

The Oral Glucose Tolerance Test-Is It Time for a Change?-A Literature Review with an Emphasis on Pregnancy

Globally, gestational diabetes (GDM) is increasing at an alarming rate. This increase is linked to the rise in obesity rates among women of reproductive age. GDM poses a major global health problem due to the related micro- and macro-vascular complications of subsequent Type 2 diabetes and the impact on the future health of generations through the long-term impact of GDM on both mothers and their infants. Therefore, correctly identifying subjects as having GDM is of utmost importance. The oral glucose tolerance test (OGTT) has been the mainstay for diagnosing gestational diabetes for decades. However, this test is deeply flawed. In this review, we explore a history of the OGTT, its reproducibility and the many factors that can impact its results with an emphasis on pregnancy.

Applying Nanomaterials to Modern Biomedical Electrochemical Detection of Metabolites, Electrolytes, and Pathogens

Personal biosensors and bioelectronics have been demonstrated for use in out-of-clinic biomedical devices. Such modern devices have the potential to transform traditional clinical analysis into a new approach, allowing patients or users to screen their own health or warning of diseases. Researchers aim to explore the opportunities of easy-to-wear and easy-to-carry sensors that would empower users to detect biomarkers, electrolytes, or pathogens at home in a rapid and easy way. This mobility would open the door for early diagnosis and personalized healthcare management to a wide audience. In this review, we focus on the recent progress made in modern electrochemical sensors, which holds promising potential to support point-of-care technologies. Key original research articles covered in this review are mainly experimental reports published from 2018 to 2020. Strategies for the detection of metabolites, ions, and viruses are updated in this article. The relevant challenges and opportunities of applying nanomaterials to support the fabrication of new electrochemical biosensors are also discussed. Finally, perspectives regarding potential benefits and current challenges of the technology are included. The growing area of personal biosensors is expected to push their application closer to a new phase of biomedical advancement.

Reusable optofluidic point-of-care testing platform with lyophilized specific antibody for fluorescence detection of cholylglycine in serum

A reusable optofluidic point-of-care testing platform (OPOCT) was successfully constructed through integrating evanescent wave fluorescence technology into an all-fiber-based optofluidic system. The compact design of the OPOCT allows it to be portable and suitable for on-site sensitive determination of biomarkers in serum without complicated and costly procedures. The sensitivity of 90.9 pM for antibody determination is observed thanks to the high transmission efficiency of excitation light and fluorescence in the OPOCT. The affinity constant between cholylglycine (CG) and anti-CG antibody was quantified using this platform based on the proposed theory. Using the lyophilized fluorescence-labeled specific antibody and reusable fiber optic biosensor, the OPOCT is applied to the one-step sensitive determination of CG in serum, which eliminates the dearth associated with liquid reagent handling, disposable biosensors, and user intervention. A limit of detection of 0.025 μg/mL for CG is obtained, which is far more than adequate for meeting diagnostic requirements. The matrix effect of serum samples on the evanescent wave-based optofluidic biosensor can be effectively reduced by simple dilution of serum samples. The performance of the OPOCT also compared favorably with that of a commercial turbidimetric inhibition immunoassay through analyzing multiple serum samples. This platform is ready to expand to measure any other biomarker by using its specific antibody. The simplicity, sensitivity, cost-effectiveness, and robustness of the OPOCT enable the early diagnosis of disease and making a timely clinical decision. Graphical abstract .

High Prevalence of Gestational Diabetes Mellitus in Rural Tanzania-Diagnosis Mainly Based on Fasting Blood Glucose from Oral Glucose Tolerance Test

Gestational diabetes mellitus (GDM) is associated with poor pregnancy outcomes and increased long-term risk of metabolic diseases for both mother and child. In Tanzania, GDM prevalence increased from 0% in 1991 to 19.5% in 2016. Anaemia has been proposed to precipitate the pathogenesis of GDM. We aimed to examine the prevalence of GDM in a rural area of Tanzania with a high prevalence of anaemia and to examine a potential association between haemoglobin concentration and blood glucose during pregnancy. The participants were included in a population-based preconception, pregnancy and birth cohort study. In total, 538 women were followed during pregnancy and scheduled for an oral glucose tolerance test (OGTT) at week 32-34 of gestation. Gestational diabetes mellitus was diagnosed according to the WHO 2013 guidelines. Out of 392 women screened, 39% (95% CI: 34.2-44.1) had GDM, the majority of whom (94.1%) were diagnosed based solely on the fasting blood sample from the OGTT. No associations were observed between haemoglobin or ferritin and glucose measurements during pregnancy. A very high prevalence of GDM was found in rural Tanzania. In view of the laborious, costly and inconvenient OGTT, alternative methods such as fasting blood glucose should be considered when screening for GDM in low- and middle-income countries.