Fasting capillary glucose as a screening test for gestational diabetes mellitus

Associations between diet quality, blood pressure, and glucose levels among pregnant women in the Asian megacity of Jakarta

BACKGROUND

The prevalence of gestational hypertension and diabetes in pregnancy is increasing worldwide. Diet is a modifiable factor that may influence these conditions, but few studies have examined the association between diet quality and blood pressure and glucose profiles among pregnant women. Data are especially scarce for women in low- and middle-income countries (LMICs), where 90% of global pregnancies occur, and in urban settings. We, therefore, assessed these associations among 174 pregnant women in the Asian megacity of Jakarta in a cross-sectional study of the Brain Probiotic and LC-PUFA Intervention for Optimum Early Life (BRAVE) project.

METHODS

Trained field-enumerators collected socio-demographic characteristics, measured Mid-Upper Arm Circumference (MUAC), and assessed diet by two 24-hour recalls, which were used to calculate the Alternate Healthy Eating Index for Pregnancy (AHEI-P). Blood pressure was measured by automated sphygmomanometer, and fasting blood glucose by capillary glucometer. General linear models were used to identify associations.

RESULTS

The median AHEI-P score was 47.4 (IQR 19.1-76.6). The middle tertile of the AHEI-P score (39.59-56.58) was associated with a 0.4 SD (standardized effect size, 95% CI -0.7 to -0.06; p = 0.02) lower diastolic blood pressure compared with the lowest tertile (<39.59), after adjustment for level of education, smoking status, MUAC, gestational age, history of hypertension, and family history of hypertension. However, no associations were found between the AHEI-P score and systolic blood pressure and blood glucose.

CONCLUSION

Higher diet quality was associated with lower diastolic blood pressure among pregnant women in an urban LMIC community, but not with systolic blood pressure and blood glucose. A behavioral change intervention trial would be warranted to confirm the influence of diet quality on blood pressure and glucose levels and among pregnant women, and even before pregnancy.

Capillary glucose concentration during oral glucose tolerance test for the diagnosis of gestational diabetes

OBJECTIVE

To assess concordance between two point-of-care testing (POCT) devices and the standard laboratory method in screening for gestational diabetes mellitus (GDM) in Huesca.

METHODS

Pregnant women who met criteria for an oral glucose tolerance test (OGTT) and attended the laboratory between October 2017 and November 2018 were recruited in this prospective observational study. Glucose was measured in venous (laboratory) and capillary blood (Accu-Chek or Contour Next glucometers). GDM was diagnosed attending to NDDG criteria for venous samples or capillary-specific cut-off. Linear regression, Passing-Bablok, Bland-Altman, and the kappa coefficient were used to study concordance between POCT and laboratory method.

RESULTS

Data from 109 women were analyzed (57 for Accu-Chek, 52 for Contour Next). Statistical analyses showed good agreement between both POCT and laboratory method. There were no statistical differences in fasting glucose measurements between capillary and venous samples and both POCT devices meet the ISO 15197 standard. Accu-Chek showed good agreement (k=0.629) regarding the laboratory method in classifying GDM, with an acceptable inter-evaluator bias of 3.5% (P<0.001).

CONCLUSION

POCT can be used to obtain fasting values and reduce overall waiting times for patients. Additionally, Accu-Chek can be used to diagnose GDM in remote areas applying specific cut-off values.

Characteristics of different risk factors and fasting plasma glucose for identifying GDM when using IADPSG criteria: a cross-sectional study

Background

The Swedish National Board of Health and Welfare (SNBHW) recommended the new diagnostic criteria for GDM based upon Hyperglycaemia and Adverse Pregnancy Outcomes (HAPO) study thresholds. Due to limited knowledge base, no recommendations were made on GDM screening. The aim of this study is to evaluate test characteristics of risk factors and fasting blood glucose as screening tests for diagnosing GDM using diagnostic thresholds based upon HAPO study 1.75/2.0 (model I/II respectively) odds ratio for adverse pregnancy outcomes.

Methods

This cross-sectional, population-based study included all pregnant women who attended maternal health care in Örebro County, Sweden between the years 1994–96. A 75 g OGTT with capillary fasting and 2-h blood glucose was offered to all pregnant women at week 28–32. Risk factors and repeated random glucose samples were collected. Sensitivity, specificity and predictive values of blood glucose were calculated.

Results

Prevalence of GDM was 11.7% with model I and 7.2% with the model II criteria. Risk factors showed 28%, (95% CI 24–32) and 31%, (95% CI 25–37) sensitivity for model I and II respectively. A fasting cut off ≥4.8 mmol/l occurred in 24% of women with 91%, (95% CI 88–94) sensitivity and 85%, (95% CI 83–86) specificity using model I while a fasting cut off ≥5.0 mmol/l occurred in 14% with 91%, (95% CI 87–94) sensitivity and 92%, (95% CI 91–93) specificity using model II.

Conclusion

Risk factor screening for GDM was found to be poorly predictive of GDM but fasting glucose of 4.8–5.0 mmol/l showed good test characteristics irrespective of diagnostic model and results in a low rate of OGTTs.

Prevalence of gestational diabetes mellitus based on various screening strategies in western Kenya: a prospective comparison of point of care diagnostic methods

Background

Early diagnosis of gestational diabetes mellitus (GDM) is crucial to prevent short term delivery risks and long term effects such as cardiovascular and metabolic diseases in the mother and infant. Diagnosing GDM in Sub-Saharan Africa (SSA) however, remains sub-optimal due to associated logistical and cost barriers for resource-constrained populations. A cost-effective strategy to screen for GDM in such settings are therefore urgently required. We conducted this study to determine the prevalence of gestational diabetes mellitus (GDM) and assess utility of various GDM point of care (POC) screening strategies in a resource-constrained setting.

Methods

Eligible women aged ≥18 years, and between 24 and 32 weeks of a singleton pregnancy, prospectively underwent testing over two days. On day 1, a POC 1-h 50 g glucose challenge test (GCT) and a POC glycated hemoglobin (HbA1c) was assessed. On day 2, fasting blood glucose, 1-h and 2-h 75 g oral glucose tolerance test (OGTT) were determined using both venous and POC tests, along with a venous HbA1c. The International Association of Diabetes in Pregnancy Study Group (IADPSG) criteria was used to diagnose GDM. GDM prevalence was reported with 95% confidence interval (CI). Specificity, sensitivity, positive predictive value, and negative predictive value of the various POC testing strategies were determined using IADPSG testing as the standard reference.

Results

Six hundred-sixteen eligible women completed testing procedures. GDM was diagnosed in 18 women, a prevalence of 2.9% (95% CI, 1.57% - 4.23%). Compared to IADPSG testing, POC IADPSG had a sensitivity and specificity of 55.6% and 90.6% respectively while that of POC 1-h 50 g GCT (using a diagnostic cut-off of ≥7.2 mmol/L [129.6 mg/dL]) was 55.6% and 63.9%. All other POC tests assessed showed poor sensitivity.

Conclusions

POC screening strategies though feasible, showed poor sensitivity for GDM detection in our resource-constrained population of low GDM prevalence. Studies to identify sensitive and specific POC GDM screening strategies using adverse pregnancy outcomes as end points are required.

Trials registration

Clinical trials.gov: NCT02978807, Registered 29 November 2016.

Gestational diabetes mellitus: Screening with fasting plasma glucose

Fasting plasma glucose (FPG) as a screening test for gestational diabetes mellitus (GDM) has had a checkered history. During the last three decades, a few initial anecdotal reports have given way to the recent well-conducted studies. This review: (1) traces the history; (2) weighs the advantages and disadvantages; (3) addresses the significance in early pregnancy; (4) underscores the benefits after delivery; and (5) emphasizes the cost savings of using the FPG in the screening of GDM. It also highlights the utility of fasting capillary glucose and stresses the value of the FPG in circumventing the cumbersome oral glucose tolerance test. An understanding of all the caveats is crucial to be able to use the FPG for investigating glucose intolerance in pregnancy. Thus, all health professionals can use the patient-friendly FPG to simplify the onerous algorithms available for the screening and diagnosis of GDM - thereby helping each and every pregnant woman.

Outcomes of women with gestational diabetes mellitus in Sweden

OBJECTIVE

The number of women with gestational diabetes mellitus (GDM) during pregnancy is increasing around the world and in our region in the south Sweden 1.2% of all pregnant women received the GDM diagnosis in the 90s and now it is about 2.2%. The aim of this study was to compare women with GDM 1995-99 against women with GDM 2012-13 regarding eventual differences in demographics and pregnancy outcome.

STUDY DESIGN

In our region in Sweden, all pregnant women are tested for GDM with a 2-h 75g oral glucose tolerance test and the 2-h cut off value for GDM is ≥10.0mmol/l in capillary plasma glucose. 1995-99 there were 131 women with GDM and their medical journals were compared against the 210 women with GDM during 2012-13. The same screening and diagnostic method was uses during the whole time period.

RESULTS

In the 2012-13 GDM pregnancies there were more non-Scandinavian women, more women with insulin treatment during pregnancy and a higher frequency of cesarean deliveries compared to 1995. First weight of the women during GDM pregnancy 2012-13 was significantly higher than the weight of women with GDM 1995-99, 71kg (43-138; n=201) and 65kg (43-133; n=125) (p=0.008) respectively. However, there was no significant difference in weight of the mother at delivery. Birth weight of the child in GDM pregnancies 1995-99 was 3722.4g±578.2 (n=109; p=0.009), and in GDM pregnancies 2012-13 3555.6g±465.8 (n=162).

CONCLUSION

Even though women with GDM 2012-13 weigh more when they start the pregnancy there is no difference in weight at delivery compared to women with GDM 1995-99. This is also reflected on the newborn, that 2012-13 had significantly lower birth weight but with the same gestational length as 1995-1999. We believe that this is due to a more active and intense treatment of women with GDM during pregnancy together with higher frequency of cesarean delivery. Prevention of large infants is crucial to avoid complications during delivery.

Towards normalized birthweight in gestational diabetes mellitus

INTRODUCTION

The objective was to describe pregnancy outcomes in gestational diabetes mellitus (GDM) in comparison with general population in Sweden.

MATERIAL AND METHODS

A population-based retrospective study using University hospital records and Swedish Medical Birth Register was carried out on pregnant women with well-monitored GDM (n = 870) and pregnancies in the Swedish Medical Birth Register (n = 1 553 420). Data from GDM pregnancies was compared to pregnancies in the whole of Sweden during 1995-2010. The main outcome measures were age, first bodyweight in and weight gain during pregnancy, birthweight, gestational length, percentage of cesarean deliveries.

RESULTS

First maternal bodyweight during the GDM pregnancy was higher than in the general population, 72.4 ± 17.4 kg (n = 837) vs. 67.3 ± 12.6 kg (n = 1 383 000; p < 0.0001). Women with GDM gained less weight during pregnancy 9.9 ± 5.8 kg (n = 703) compared to the general population, 13.2 ± 5.7 kg (n = 482 860; p < 0.0001). Mean birthweight in GDM pregnancies was 3564 ± 500 g (n = 743) compared to 3580 ± 483 g for the general population (n = 1 316 364; p = ns). Gestational length was slightly shorter, 39.4 weeks in the GDM pregnancies (n = 683) vs. 39.5 weeks (n = 1 319 876; p = 0.02) in the general population and the percentage of cesarean deliveries higher in the GDM pregnancies at 18.4% (n = 712) vs. 13.3% (n = 1 322 242; p < 0.0001).

CONCLUSIONS

Though many studies have shown an increased risk of macrosomia in GDM pregnancies, remaining even after ambitious management programs, we show no difference in birthweight. This may be due to a combination of intense efforts to achieve good metabolic control during pregnancy and shorter pregnancy duration. Preventing unduly large babies is crucial to minimize adverse pregnancy outcomes.

Comparative Study of Fasting Plasma Glucose Concentration and Glucose Challenge Test for Screening Gestational Diabetes Mellitus

Background

To compare the sensitivity and specificity of fasting plasma glucose (FPG) with that of standard glucose challenge test (GCT).

Materials and methods

Eighty-nine eligible pregnant women underwent GCT between 24th and 28th gestational week, followed by a diagnostic 3 hours 100 gm oral glucose tolerance test within 1 week. Out patient clinic in Father Muller Medical College Hospital, Mangalore. Data was analyzed for significance by chi-square test.

Results

Fasting plasma glucose concentration at a threshold value of 90 mg/dl and GCT at recommended standard threshold of 140 mg/dl yielded sensitivities of 66.7% and 100% respectively and specificities of 87.3% and 46.5% respectively. Reducing the threshold value of FPG to 80 mg/dl increased the sensitivity of test to 91.7% with specificity of 54.9% which was comparable to standard GCT, in our study.

Conclusion

Measuring FPG concentration using a cut-off of. 80 mg/dl is an easier, tolerable and more cost effective procedure than GCT for detecting more severe cases of GDM, i.e. the diabetes mellitus group. In resource poor settings with population belonging to average risk or high risk category, FPG at a cut-off of 90 mg/dl can be used to screen GDM.

How to cite this article

Sham S, Bhat BPR, Kamath A. Comparative Study of Fasting Plasma Glucose Concentration and Glucose Challenge Test for Screening Gestational Diabetes Mellitus. J South Asian Feder Obst Gynae 2014;6(2):75-78.

Fasting capillary glucose as a screening test for ruling out gestational diabetes mellitus

OBJECTIVE

A common approach to screening for gestational diabetes mellitus (GDM) is the testing of all pregnant women with a one-hour, 50 g glucose challenge test (GCT), followed by a diagnostic oral glucose tolerance test (OGTT) when the GCT is positive (≥ 7.8 mmol/L). As only a small subset of those with a positive GCT will have GDM, many more women undergo the OGTT than may be necessary. In this context, we hypothesized that measurement of fasting capillary glucose (FCG) could provide a strategy for reducing the number of unnecessary OGTTs. Thus, we sought to identify a threshold level of FCG below which GDM could be ruled out following a positive GCT, without need for the OGTT.

METHODS

Following a positive GCT, 888 women underwent measurement of FCG prior to their OGTT. We evaluated the test characteristics of FCG for identifying the 209 women diagnosed with GDM on the OGTT.

RESULTS

Fasting capillary glucose was positively associated with each glucose measurement on the OGTT (all P < 0.001) and inversely related to insulin sensitivity and pancreatic beta-cell function (both P < 0.001). As FCG increased, the prevalence of GDM progressively rose (P < 0.001). However, the area under the curve of the receiver-operating characteristic curve for FCG in predicting GDM was modest (0.67). Although using an FCG threshold of 4.8 mmol/L could reduce the number of OGTTs by 28.4%, this approach would miss 18.2% of cases of GDM.

CONCLUSION

Fasting capillary glucose is associated with glycemia, insulin sensitivity, and pancreatic beta-cell function. However, a single FCG measurement is insufficient for reliably ruling out GDM after an abnormal GCT.

Screening for hyperglycaemia in pregnancy: Consensus and controversy

Policy decisions on whether to implement screening programmes depend on whether the proposed programmes meet a set of criteria laid down by the World Health Organization. Screening for hyperglycaemia in pregnancy (HGP) does not meet all the criteria. However the case for screening has been strengthened by a number of recent developments, including: rising prevalence of HGP because of increasing maternal age and BMI; the results of the Hyperglycaemia and Adverse Pregnancy Outcomes study, showing that adverse effects of HGP are seen over a wider range of plasma glucose levels than previously thought; two large trials which showed the benefits of treating lesser degrees of HGP; trials showing that metformin and glibenclamide were effective and safe alternatives to immediate insulin in those without good control on lifestyle measures alone. However uncertainties remain around the threshold for treatment, and on the best screening strategy.

First trimester fasting hyperglycemia as a predictor for the development of gestational diabetes mellitus

OBJECTIVE

Screening for gestational diabetes mellitus (GDM) is usually done at 24-28 weeks of gestation. Our goal was to study the association between first trimester fasting plasma glucose level and GDM risk and to evaluate its efficacy as a screening test for GDM in comparison to a traditional risk factor, pregestational body mass index (BMI).

STUDY DESIGN

The charts of all patients who delivered in our hospital between June 2001 and June 2006 were reviewed. Only subjects with a singleton pregnancy and a recorded first trimester fasting glucose level and BMI were studied. Women with pregestational diabetes mellitus, fasting glucose level >105mg/dl or delivery at <24 weeks were excluded. Screening properties of both fasting glucose level and BMI were calculated and compared using receiver operator characteristic curves.

RESULTS

GDM was diagnosed in 135 of the 4876 women included in this study. Fasting glucose cut-off levels of 80-85mg/dl yielded sensitivities of 75-55% and specificities of 52-75% for GDM prediction. BMI cut-off values of 25-28 had sensitivities of 60-40% and specificities of 72-86% for GDM prediction. Receiver operator curves for fasting glucose levels and BMI showed similar performance in predicting GDM (area under curve 0.72±0.023 vs. 0.74±0.021 (P=0.44)). There was approximately a 1.5-fold increase in the risk of developing GDM with each 5mg/dl increase in fasting glucose or 3.5kg/m² increase in BMI.

CONCLUSION

Higher first trimester fasting glucose levels, within the normoglycemic range, constitute an independent risk factor for the development of GDM among young pregnant women.

Surprisingly low compliance to local guidelines for risk factor based screening for gestational diabetes mellitus - A population-based study

Background

Screening for gestational diabetes mellitus (GDM) is routine during pregnancy in many countries in the world. The screening programs are either based on general screening offered to all pregnant women or risk factor based screening stipulated in local clinical guidelines. The aims of this study were to investigate: 1) the compliance with local guidelines of screening for GDM and 2) the outcomes of pregnancy and birth in relation to risk factors of GDM and whether or not exposed to oral glucose tolerance test (OGTT).

Methods

This study design was a population-based retrospective cross-sectional study of 822 women. A combination of questionnaire data and data collected from medical records was applied. Compliance to the local guidelines of risk factor based screening for GDM was examined and a comparison of outcomes of pregnancy and delivery in relation to risk factor groups for GDM was performed.

Results

Of the 822 participants, 257 (31.3%) women fulfilled at least one criterion for being exposed to screening for GDM according to the local clinical guidelines. However, only 79 (30.7%) of these women were actually exposed to OGTT and of those correctly exposed for screening, seven women were diagnosed with GDM. Women developing risk factors for GDM during pregnancy had a substantially increased risk of giving birth to an infant with macrosomia.

Conclusion

Surprisingly low compliance with the local clinical guidelines for screening for GDM during pregnancy was found. Furthermore, the prevalence of the risk factors of GDM in our study was almost doubled compared to previous Swedish studies. Pregnant women developing risk factors of GDM during pregnancy were found to be at substantially increased risk of giving birth to an infant with macrosomia. There is a need of actions improving compliance to the local guidelines.

Gestational diabetes: fasting capillary glucose as a screening test in a multi-ethnic, high-risk population

AIMS

In populations at high risk of gestational diabetes mellitus (GDM), screening every pregnant woman by an oral glucose tolerance test (OGTT) is very demanding. The aim of this study was to determine the value of the fasting capillary glucose (FCG) as a screening test for GDM.

METHODS

FCG was measured by a plasma-correlated glucometer in 1465 pregnant women who underwent a one-step diagnostic 75-g OGTT for universal screening of GDM.

RESULTS

One hundred and ninety-six (13.4%) women had GDM as defined by the criteria of the American Diabetes Association. The area under the receiver operating characteristic curve (AUC) of the FCG was 0.83 (95% confidence interval 0.80-0.86). A FCG threshold of 4.7 mmol/l (at an acceptable sensitivity of 86.0%) independently could rule-out GDM in 731 (49.9%) women, while the FCG could rule-in GDM (100% specificity) in 16 (1.1%) additional women; therefore, approximately half of the women would not need to continue with the cumbersome OGTT.

CONCLUSIONS

Screening using a FCG significantly reduces the number of OGTTs needed for the diagnosis of GDM. Wider assessment, particularly in low-risk populations, would confirm the potential value of the FCG as a screening test for GDM.