Gestational Diabetes Mellitus: Using the Fasting Plasma Glucose Level to Simplify the International Association of Diabetes and Pregnancy Study Groups Diagnostic Algorithm in an Adult South Asian Population.

OBJECTIVES: To evaluate the value of the fasting plasma glucose (FPG) level for simplifying the International Association of Diabetes and Pregnancy Study Groups (IADPSG) diagnostic algorithm of gestational diabetes mellitus (GDM) in a South Asian population. METHODS: In 6,520 pregnant women undergoing universal screening with the 75 g oral glucose tolerance test (OGTT), the area under receiver operating characteristic curve was used to determine the overall FPG performance to detect GDM (IADPSG criteria). Specifically, 2 different FPG thresholds of the OGTT were used to rule in and rule out GDM so as to decrease the need for the cumbersome OGTT. RESULTS: GDM was present in 1,193 (18.3%) women. The FPG 1) area under receiver operating characteristic curve (95% CI) was 0.909 (0.898 to 0.920); 2) threshold of ≥5.1 mmol/L independently could rule in GDM in 708 (10.9%) women (100% specificity); 3) threshold of <4.3 mmol/L independently could rule out GDM in an additional 2,389 (36.6%) women (95.6% sensitivity). CONCLUSIONS: By circumventing nearly one half the OGTTs, an initial FPG can simplify the onerous GDM diagnostic IADPSG algorithm in this population parochially and in countries with large South Asian immigrant populations-without compromising medical care.

Breast cancer protection by genomic imprinting in close kin families.

Human inbreeding generally reduces breast cancer risk (BCR). When the parents are biologically related, their infants have a lower birth weight due to smaller body organs. The undersized breasts, because of fewer mammary stem cells, have a lower likelihood of malignant conversion. Fetal growth is regulated by genomically imprinted genes which are in conflict; they promote growth when derived from the father and suppress growth when derived from the mother. The kinship theory explicates that the intensity of conflict between these genes affects growth and therefore the size of the newborn. In descendants of closely related parents, this gene clash is less resulting in a smaller infant. In this review, we elucidate the different mechanisms by which human inbreeding affects BCR, and why this risk is dissimilar in different inbred populations.

Hemoglobin A2 Lowered by Iron Deficiency and α -Thalassemia: Should Screening Recommendation for ß -Thalassemia Change?

Screening for ß -thalassemia trait (BTT) relies on measuring hemoglobin (Hb) A2. Since multiple factors can affect HbA2 levels, the screening can become unreliable. In 1356 healthy Arabs enrolled into a federally funded premarital BTT screening program, the effects of iron deficiency (ID), α (+)-thalassemia trait, gender, smoking, and tribalism on HbA2 were studied. The complete blood count and hemoglobin fractions were determined on the entire cohort; serum ferritin (<15 µ g/L) in 391 subjects was used to determine ID. BTT was present in 29 (2.1%) subjects (HbA2 > 3.5%). Among 77(20.3%) subjects with ID, the mean HbA2 (2.30 ± 0.23%) was 0.2% lower than in subjects without iron deficiency (2.50 ± 0.24%, P < 0.0001). In 65 (38%)/172 subjects with phenotypic α (+)-thalassemia trait, the mean HbA2 (2.43 ± 0.24%) was 0.13% lower than in subjects without α (+)-thalassemia trait, P < 0.0001. The mean HbA2 did not differ between males and females, smokers and nonsmokers, and between the tribes. Thus, 35 (2.6%) subjects with HbA2 between 3.2 and 3.5% were at a risk of false negative diagnosis of BTT. Since iron deficiency and α (+)-thalassemia are both common and both lower HbA2, modifications in screening recommendations for BTT are proposed.

Gestational diabetes in a tertiary care hospital: implications of applying the IADPSG criteria.

BACKGROUND: The American Diabetes Association has endorsed the International Association of Diabetes and Pregnancy Groups (IADPSG) recommendation that every pregnant woman should undergo the 75 g oral glucose tolerance test (OGTT) to screen for gestational diabetes mellitus (GDM). PURPOSE: To find the cost and workload implications of switching from the current two-step screening of GDM to the one-step IADPSG approach. METHODS: The cost (US $) and laboratory workload units (WLU) were calculated for three possible strategies: (1) 50 g glucose screen, if positive, followed by the 100 g OGTT; (2) universal 75 g OGTT; and (3) screening with the initial fasting plasma glucose of the OGTT. RESULTS: For the 1,101 pregnant women screened in 1 year, the cost of the three strategies was $ 31,985, $ 55,250 and $ 35,875, respectively; the laboratory burden was 28,975 WLU, 18,662 WLU and 12,215 WLU, respectively. CONCLUSIONS: Switching to the one-step, strategy 2 (IADPSG) would increase the cost by 42 % but decrease the laboratory workload by 36 % compared to the two-step, strategy 1. However, an initial screen by the fasting plasma glucose of the OGTT is the ideal strategy, both in terms of cost and laboratory workload.

Gestational diabetes screening: the low-cost algorithm.

The American Diabetes Association has endorsed the demanding recommendation by the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) that every pregnant woman should undergo the oral glucose tolerance test (OGTT) for the screening of gestational diabetes mellitus (GDM). The aim of this study was to find out if the fasting plasma glucose (FPG) and newer emerging technologies could simplify the cumbersome IADPSG algorithm. Two FPG thresholds (of the OGTT) were used to rule in and rule out GDM in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) cohort (n = 23316) and a population at high risk for GDM (n = 10283). For the HAPO cohort and the high-risk population, respectively, FPG thresholds of: (a) ≥ 5.1 mmol/L (specificity 100%) independently ruled in GDM in 1769 (8.3%) women and 2975 (28.9%) women; and (b) ≤ 4.4 mmol/L ruled out GDM in 11526 (49.4%) women (84.1% sensitivity) and 2228 (21.7%) women (95.4% sensitivity). Use of the FPG independently could have avoided 13295 (57.0%) and 5203 (50.6%) OGTTs in the 2 groups. The initial FPG-by significantly reducing the number of cumbersome OGTTs needed-can make the IADPSG recommendations more acceptable worldwide. The number of GDM women missed is population dependent. For low-resource countries, alternative newer and cheaper tests in development hold an exciting future.

Gestational diabetes: an evaluation of serum fructosamine as a screening test in a high-risk population.

AIM: To evaluate the value of serum fructosamine as a screening test for gestational diabetes mellitus (GDM). METHODS: 849 pregnant women underwent the one-step 75 g oral glucose tolerance test (OGTT) for universal screening of GDM. The fasting serum fructosamine (cFruc) was assessed using the area under the receiver operating characteristic curve (AUC). The GDM diagnostic criteria used were those of the American Diabetes Association; however, the cFruc performance was also evaluated using criteria of the World Health Organization, Australian (ADIPS), European (EASD) and International Association of Diabetes and Pregnancy Study Groups (IADPSG). RESULTS: 113 (13.3%) women had GDM. The AUC of the cFruc was 0.60 (95% CI 0.54-0.66). A cFruc threshold of 237 µmol/l achieved an acceptable sensitivity of 85.8% (95% CI 78.0-91.0%), but the associated specificity remained poor at 23.4% (95% CI 20.0-27.0%) with a positive predictive value of just 14.7%. Overall, over 4 out of 5 pregnant women, being over this cutoff, would need the confirmatory OGTT. No cFruc threshold reached acceptable likelihood ratios to rule-in or rule-out GDM. The AUC for cFruc remained unacceptable independent of the diagnostic criteria. CONCLUSIONS: Despite all the advances in technology, serum fructosamine is a poor test to screen for GDM.

Gestational diabetes: using a portable glucometer to simplify the approach to screening.

BACKGROUND: In populations at a high-risk for gestational diabetes (GDM), the recommendation of screening every pregnant woman with the oral glucose tolerance test (OGTT) is very demanding. AIM: To assess the usefulness of the portable, plasma optimized glucometer in simplifying the approach to screening of GDM. METHODS: 1,662 pregnant women underwent the one-step 75 g OGTT for routine screening of GDM, as defined by the criteria of the American Diabetes Association. The glucometer was used to measure the initial fasting venous whole blood glucose (FBG) to assess its value as a screening test in predicting the need to proceed with the OGTT. RESULTS: 186 (11.2%) women had GDM. The area under the receiver operating characteristic curve (AUC) of the FBG was 0.876 (95% CI 0.847-0.906). A FBG threshold (at an acceptable sensitivity of 85%) independently could 'rule-out' GDM in 1,138 (68.5%) women; i.e. over two-thirds of the women would not need to continue with the cumbersome OGTT. CONCLUSIONS: Using the glucometer to initially measure the venous FBG as a screen can help to significantly reduce the number of OGTTs needed for the diagnosis of GDM. This algorithm offers a simple, practical, cost-effective and patient-friendly approach for the screening of GDM.

Nutritional iron deficiency: an evolutionary perspective.

Iron deficiency, with or without iron-deficiency anemia, is so ubiquitous that it affects all populations of the world irrespective of race, culture, or ethnic background. Despite all the latest advances in modern medicine, improved nutrition, and the ready availability of cheap oral iron, there is still no good explanation for the widespread persistence of iron deficiency. It is possible that the iron deficiency phenotype is very prevalent because of many factors other than the commonly cited causes such as a decreased availability or an increased utilization of iron. Several thousand years ago, human culture changed profoundly with the agrarian revolution, when humans turned to agriculture. Their diet became iron deficient and new epidemic infections emerged due to crowding and lifestyle changes. There is convincing evidence that iron deficiency protects against many infectious diseases such as malaria, plague, and tuberculosis as shown by diverse medical, historical, and anthropologic studies. Thus, this change of diet increased the frequency of iron deficiency, and epidemic infections exerted a selection pressure under which the iron deficiency phenotype survived better. Multiple evolutionary factors have contributed in making iron deficiency a successful phenotype. We analyze some of the recent findings of iron metabolism, the theories explaining excessive menstruation in human primates, the unexplained relative paucity of hemochromatosis genes, the former medical practice of "blood-letting," and other relevant historical data to fully understand the phenomenon of iron deficiency. We suggest that, due to a long evolutionary persistence of iron deficiency, efforts at its prevention will take a long time to be effective.

Gestational diabetes: fasting and postprandial glucose as first prenatal screening tests in a high-risk population.

OBJECTIVE: To evaluate the value of fasting (FPG) and 2-hour postprandial (PPG) plasma glucose as screening tests for gestational diabetes mellitus (GDM) in a high-risk population during early pregnancy. STUDY DESIGN: At their first prenatal visit, 708 women underwent FPG and PPG for universal screening for GDM, with the diagnosis confirmed by the 75-g oral glucose tolerance test (World Health Organization criteria). The area under the receiver operating characteristic curve (AUC) was used to analyze the performance of the 2 screening tests. RESULTS: Of 184 (25.9%) women with GDM, 79 (42.9%) were identified before 18 weeks. The AUC for FPG to predict GDM was 0.579 (95% CI 0.531-0.627). Though a threshold of 85 mg/dL achieved minimally acceptable sensitivity, 79.9%, the corresponding specificity remained poor, 27.5%, with a false positive rate (FPR) of 72.5%. The AUC for PPG was 0.717 (95% CI 0.670-0.765); a cutoff of 95 mg/dL achieved a sensitivity of 79.9% and FPR of 53.1%. CONCLUSION: Though GDM could be diagnosed in > 40% women in early pregnancy at their first prenatal visit, the poor specificity and high FPR of FPG and PPG, alone or in combination, make them unsuitable screening tests for GDM.

Fasting plasma glucose as a screening test for gestational diabetes mellitus.

Although debated, most preeminent expert panels recommend routine screening for gestational diabetes mellitus (GDM). Among the many tests that have been used and evaluated for the screening of GDM, the fasting plasma glucose (FPG) remains very appealing. It is easy to administer, well tolerated, inexpensive, reproducible and patient friendly. However attractive, the FPG has given varied results in different populations and its use as a screening test for GDM remains uncertain. This review will objectively assess the available studies to find the real value of FPG as a screening test for GDM.

Gestational diabetes: a reappraisal of HBA1c as a screening test.

BACKGROUND: Recent technological advances have made HBA1c a more standardized and user-friendly test with wide availability. This study evaluated HBA1c as a screening test for gestational diabetes mellitus (GDM) in a high-risk population. METHODS: A total of 442 pregnant women were assessed by HBA1c. Two thresholds were used to "rule in or rule out" GDM, which was confirmed by the "gold-standard" 75-g OGTT (World Health Organization criteria). RESULTS: Eighty-four (19%) women had GDM while 358 (81%) women were normal; there was a complete overlap of the HBA1c histograms of the two populations. The area under receiver operating characteristic curve of HBA1c to detect GDM was 0.54 (95% CI 0.48-0.61). Using a value of <5.5% to rule out GDM; a sensitivity of 82.1% was achieved, with 15 (16.7%) of 90 women below the threshold being false-negatives (NPV = 83.3%). Using a threshold of HBA1c > or = 7.5% to rule-in GDM; the specificity was 95.8% with 15 (71.4%) of 21 patients over the threshold being false-positives (PPV = 28.6%). HBA1c would eliminate the need for an OGTT in 25.1% (111/442) of whom 27% (30/111) women would be misclassified. At any HBA1c threshold with an acceptable sensitivity, the false-positive rate remained high making it necessary for too many healthy women to undergo the confirmatory OGTT. CONCLUSION: Despite all the progress in methodology, HBA1c remains a poor test to screen for GDM.