Oral Glucose Tolerance Test Test Research Articles

Fetal growth is associated with maternal fasting plasma glucose at first prenatal visit.

AimsFasting plasma glucose (FPG) concentration measured at the first prenatal visit is a predictor of gestational diabetes mellitus (GDM); however, whether this test is indicative of fetal growth has not been clarified. Thus, the purpose of this study was to determine whether birth weight and birth length were related to FPG levels at the first prenatal visit.Materials and MethodsResearch samples were collected from pregnant women who took an FPG test at their first prenatal visit (10–24 gestational weeks), received regular prenatal care, and delivered in our center. FPG value, maternal pre-gravid BMI, weight gain before FPG test, before and after Oral Glucose Tolerance Test (OGTT), neonatal birthweight, birth length, Ponderal Index and birthing method were recorded for analysis. Data were analyzed by independent sample t test, Pearson correlation, and Chi-square test, followed by partial correlation or logistic regression to confirm differences. Statistical significance level was α = 0.05.Results2284 pregnant women, including 462 GDM and 1822 with normal glucose tolerance (NGT) were recruited for the present study. FPG concentration at the first prenatal visit was associated with neonatal birth weight (partial correlation coefficient r′ = 0.089, P<0.001) and birth length (partial correlation coefficient r′ = 0.061, P = 0.005), but not with Ponderal Index or birthing method. Maternal pre-gravid BMI was associated with FPG value (partial correlation coefficient r′ = 0.113, P<0.001). FPG concentration at the first prenatal visit (OR = 2.945, P<0.001), weight gain before OGTT test (OR = 1.039, P = 0.010), and age (OR = 1.107, P<0.001) were independent related factors of GDM.ConclusionFasting plasma glucose concentration at the first prenatal visit is associated with fetal growth. Maternal pre-gravid BMI and weight gain are related to glucose metabolism.

Kidney function, β-cell function and glucose tolerance in older men.

Kidney dysfunction induces insulin resistance, but it is unknown if β cell function is affected. To investigate insulin release (β cell function) and glucose tolerance following a standardized oral glucose tolerance test (OGTT) across kidney function strata. Community-based cohort study from the Uppsala Longitudinal Study of Adult Men (ULSAM). PARTICIPANTS AND MAIN OUTCOME MEASURE: Included were 1015 nondiabetic Swedish men aged 70-71 years. All participants underwent OGTT and euglycaemic hyperinsulinaemic clamp (HEGC) tests, allowing determination of insulin sensitivity, β cell function, and glucose tolerance. Kidney function was estimated by cystatin C-algorithms. Mixed models were used to identify determinants of insulin secretion after the hyperglycemic load. As many as 466 (46%) of participants presented moderate-advanced kidney disease. Insulin sensitivity (by HEGC) decreased across decreasing kidney function quartiles. After the OGTT challenge, however, β cell function indices (area under the curve for insulin release, the estimated first phase insulin release, and the insulinogenic index) were incrementally higher. Neither the oral disposition index nor the 2-h postload glucose tolerance differed across the kidney function strata. Mixed models showed that dynamic insulin release during the OGTT was inversely associated with kidney function, despite the correction for each individual's insulin sensitivity or its risk factors. In older men, β cell function after a hyperglycemic load appropriately compensated the loss in insulin sensitivity that accompanies kidney dysfunction. As a result, the net balance between insulin sensitivity and β cell function was preserved.

Effects of dexmedetomidine on insulin secretion from rat pancreatic β cells.

Dexmedetomidine acts as a selective α2-adrenergic receptor agonist and an imidazoline receptor agonist, both of which are known to affect insulin secretion. Here, we investigated the effects of clinically relevant concentrations of dexmedetomidine on insulin secretion under in vivo conditions. Furthermore, its underlying mechanisms were examined using isolated islets in vitro. For the in vivo oral glucose tolerance test (OGTT), male Sprague-Dawley rats were randomly allocated to one of three groups (n = 7 in each group): two groups infused with dexmedetomidine at a low (group L) or a high (group H) dose, and one control group infused with the same amount of saline (group C). For the in vitro perifusion study, insulin released from isolated islets was measured during stepwise changes in glucose. Dexmedetomidine (0.1-100 µM) was added to the chamber. During the OGTT test, the insulin levels in group H were significantly lower than those in group C at 30, 60, and 90 min after glucose load. On the other hand, insulin levels in group L were comparable to those of group C at all time points. In the perfusion study, dexmedetomidine inhibited glucose-stimulated insulin secretion in a concentration-dependent manner. When co-treated with yohimbine, an α2-adrenoceptor blocker, dexmedetomidine adversely increased glucose-induced insulin secretion. However, co-treatment with idazoxan, an antagonist for α2-adrenergic and imidazoline receptors, completely abolished the action of dexmedetomidine. Dexmedetomidine had no effect on insulin secretion at sedative dose, whereas it significantly inhibited insulin secretion at supraclinical high concentrations mainly via the α2-adrenoceptor.

Risk Factors for Poor Compliance With Postpartum Oral Glucose Tolerance Testing in Women With Gestational Diabetes Mellitus

INTRODUCTION: Women with gestational diabetes mellitus (GDM) are at increased risk to develop overt diabetes; however, compliance with the postpartum 75-g oral glucose tolerance test (OGTT) is poor. We assessed rates of postpartum OGTT compliance at our institution and identified risk factors for the suspected poor compliance. METHODS: We performed a retrospective cohort study of singleton pregnancies with GDM who delivered at Columbia University Medical Center in 2011. Women were identified from institutional databases; data were abstracted from electronic medical records. Women with postpartum OGTT testing were compared with women without, and characteristics of these two groups—insurance status, parity, race, body mass index, and a history of prior GDM—were compared using χ2, Fisher's exact test, and Student's t test where appropriate. We also examined causes for noncompliance. RESULTS: Of the 6,272 women identified, 235 patients had GDM (4%). Of those, 21% had a postpartum OGTT (n=50). When compliant and noncompliant patients were compared, no significant differences existed in insurance status, age, race, parity, body mass index, or history of GDM. Privately insured patients were more likely to attend their postpartum visit than publicly insured patients (94% compared with 82%, P=.01). Patients who attended their postpartum visit were ordered for (63% compared with 53%, P=.19) and obtained postpartum OGTT (29% compared with 22%, P=.31) at similar rates. CONCLUSIONS: Compliance rates for postpartum diabetes testing are low. Regardless of compliance, the majority of women attended their postpartum visit; however, they were either not ordered a postpartum OGTT or failed to obtain it. These data are useful to develop a program targeting methods to increase compliance.

A home-based method for the detection of impaired glucose tolerance in hypertensive primary care patients

Objective. The aim of this project was to compare an oral glucose tolerance test (OGTT) partly performed in the patient's home (OGTTh) with a clinic-obtained OGTT with regard to the ability of the tests to identify patients with impaired glucose tolerance (IGT) and type 2 diabetes mellitus (DM-2). Design. A method comparison. Setting. The study was completed at two primary health care centres. Subjects. Fifty-one patients with hypertension aged 50–79 years completed both OGTT tests. Main outcome measures. Values for capillary P-glucose obtained two hours after a glucose load were compared between the two OGTT tests. Fasting plasma glucose (fP-glucose) and HbA1c were also measured. Results. Thirty-seven patients were classified in the same group (normal/IGT/DM-2) by the two tests. The index of validity based on the test's ability to identify normal or pathological values (≥ 8.9 mmol/l) was 0.75. The value for kappa was 0.66 with a sensitivity of 0.54 and a specificity of 0.82. Conclusion. OGTTh may be a useful screening method for IGT in risk groups such as hypertensive patients.

On the status of β-cell dysfunction and insulin resistance of breast cancer patient without history of diabetes after systemic treatment.

To estimate the status of β-cell dysfunction and insulin resistance of breast cancer (BC) patient without history of diabetes mellitus (DM) after systemic treatment through an oral glucose tolerance test (OGTT) and insulin releasing test (IRT). All the 128 BC patients without history of DM after systemic treatment underwent OGTT and IRT test. Fasting and 2-h glucose levels were measured to confirm undiagnosed DM and prediabetes. Insulin sensitivity was estimated by homeostasis model assessment of insulin resistance (HOMA-IR) and Matsuda index and disposition index (IGI/HOMA-IR). Insulin secretion was estimated by the insulinogenic index (IGI) [Δ insulin/Δ glucose (30-0 min)]. Insulin concentrations during the OGTT and IRT at baseline were used to derive the patterns of insulin secretion curve (pattern 1, pattern 2, pattern 3, pattern 4 and pattern 5), which were used to estimate the risk of developing DM. Of 128 BC patients without history of DM after systemic treatment, there were 46 cases (35.9%) of NGT, 60 cases (46.9%) of prediabetes and 22 cases (17.2%) of DM. The BMI of prediabetes and DM were higher than NGT groups with statistical significance. After adjusted for BMI, IGI was significantly lower in DM group but not significantly different between NGT group and prediabetes group. HOMA-IR, Matsuda index and disposition index were significantly different in DM group compared with NGT group and prediabetes and also significantly different between NGT and prediabetes groups. The total rates of patterns 4 and 5 in NGT and prediabetes groups were 15.3% (10.9 and 4.4%) and 48.3% (31.6 and 16.7%), respectively. β-Cell dysfunction and insulin resistance may appear in BC patients after systemic treatment. BC patients have high risk in development of DM even in NGT and prediabetes groups confirmed by OGTT.

On the Status and Comparison of Glucose Intolerance in Female Breast Cancer Patients at Initial Diagnosis and during Chemotherapy through an Oral Glucose Tolerance Test

AimsThis study is to estimate the status and comparison of glucose intolerance in female breast cancer patients at initial diagnosis and during chemotherapy through an oral glucose tolerance test (OGTT), as well as to learn the effect of chemotherapy on the glucose metabolism of breast cancer patients.MethodsAll the 79 breast cancer patients at initial diagnosis, with the mean age of 53.2 years, and 96 breast cancer patients before the 5th or 6th cycle of chemotherapy, with the mean age of 51.5 years, participated in the study from December 2012 to October 2013. After an overnight fast, participants underwent OGTT test, and fasting and 2-hour glucose levels were measured to identify undiagnosed diabetes and prediabetes (i.e., impaired fasting glucose or impaired glucose tolerance) in them. Previously diagnosed diabetes among the female breast cancer patients was determined on the self-report and the medical record.ResultsThe overall incidences of total normal glucose tolerance, prediabetes, diabetes in female breast cancer patients at initial diagnosis and during chemotherapy were 24.1% and 38.5% (p<0.05), 50.6% and 28.1% (p<0.05), and 25.3% and 33.3% (p>0.05), respectively, and the differences of normal glucose tolerance and prediabetes instead of diabetes between the two groups were statistically significant. About 84% of the total diabetes and prediabetes in the female breast cancer patients at initial diagnosis and 79.7% of those during chemotherapy need to be diagnosed with OGTT.ConclusionsBreast cancer patients have high incidences of diabetes and prediabetes. After chemotherapy even with steroids, some breast cancer patients with abnormal glucose metabolism may even become normal. Isolated hyperglycemia 2 hours after glucose loading is common, and OGTT should be made for breast cancer patients at initial diagnosis and during chemotherapy.

GLP-1 Responses Are Heritable and Blunted in Acquired Obesity With High Liver Fat and Insulin Resistance

OBJECTIVE Impaired incretin response represents an early and uniform defect in type 2 diabetes, but the contributions of genes and the environment are poorly characterized. RESEARCH DESIGN AND METHODS We studied 35 monozygotic (MZ) and 75 dizygotic (DZ) twin pairs (discordant and concordant for obesity) to determine the heritability of glucagon-like peptide 1 (GLP-1) responses to an oral glucose tolerance test (OGTT) and the influence of acquired obesity to GLP-1, glucose-dependent insulinotropic peptide (GIP), and peptide YY (PYY) during OGTT or meal test. RESULTS The heritability of GLP-1 area under the curve was 67% (95% CI 45-80). Cotwins from weight-concordant MZ and DZ pairs and weight-discordant MZ pairs but concordant for liver fat content demonstrated similar glucose, insulin, and incretin profiles after the OGTT and meal tests. In contrast, higher insulin responses and blunted 60-min GLP-1 responses during the OGTT were observed in the heavier as compared with leaner MZ cotwins discordant for BMI, liver fat, and insulin sensitivity. Blunted GLP-1 response to OGTT was observed in heavier as compared with leaner DZ cotwins discordant for obesity and insulin sensitivity. CONCLUSIONS Whereas the GLP-1 response to the OGTT is heritable, an acquired unhealthy pattern of obesity characterized by liver fat accumulation and insulin resistance is closely related to impaired GLP-1 response in young adults.

Antidiabetic Effect of theChrysobalanus icacoL. Aqueous Extract in Rats

Chrysobalanus icaco L. is a medicinal plant popularly known in Brazil as "Grageru" or "Abageru." It is used in African and American continents as medicinal food in the treatment of several diseases, including diabetes. This study used phytochemical screening to determine the antioxidant and α-amylase inhibitor activities of the aqueous extract (AECI) of C. icaco, and evaluated its antidiabetic potential in rodents. Phytochemical screening was performed using colorimetric tests with specific reagents. The in vitro antioxidant activity was evaluated by the scavenging activity of 2,2-diphenyl-1-picril-hydrazyl. The lethality test and behavioral screening was performed using an oral administration of 5 g/kg of AECI. The antidiabetic potential of AECI was evaluated through the oral glucose tolerance test (OGTT) and chronic hypoglycemic test at the doses of 100, 200, and 400 mg/kg (orally). Metformin was used as a reference drug in all tests. Diabetes was induced by injection of alloxan (40 mg/kg; intravenously). Phytochemical screening showed the presence of various compounds, including tannins, flavones, triterpenoids, steroids, saponins, and alkaloids. The in vitro antioxidant test demonstrated that AECI presented potent antioxidant activity. The lethality test and behavioral screening did not show lethality signs. In the OGTT test, AECI administration was not able to inhibit the elevation of glycemia. However, chronically administrated, it was able to cause a significant (P<.05) reduction of glycemia from 335±27 up to 197±15 mg/dL. These results demonstrate that the AECI presents a potential beneficial effect for diabetes.

The performance of the screening test for gestational diabetes in twin versus singleton pregnancies

Objective: To compare the performance of the 50 g glucose challenge test (GCT) and the 100 g oral glucose tolerance test (OGTT) in twin versus singleton pregnancies.Methods: A retrospective study of all women who underwent a GCT (24–28 weeks) and delivered in a single tertiary medical center (2001–2012). The performance of the GCT and the OGTT tests were compared between twin and singleton pregnancies.Results: The results of the GCT were available for 14 797 women, of whom 14 268 were singleton and 529 were twin pregnancies. Women in the twins group were characterized by a higher mean GCT result (104.7 ± 28 versus 98.5 ± 25, p < 0.001), a higher rate of GCT > 130 mg/dl (20.2% versus 11.8%, p < 0.001) or GCT >140 mg/dl (13.8% versus 9.6%, p = 0.001). The positive prediction value (PPV) for a GCT >140 mg/dl was significantly lower in the twins group for the prediction of either ≥1 abnormal values (21.1% versus 33.8%, p = 0.03) or ≥2 abnormal values (12.7% versus 23.0%, p = 0.04) in the OGTT. Twin pregnancy was independently associated with an increased risk for a GCT result >130 mg/dl [odds ratio (OR) = 2.2, 95% confidence interval (CI) 1.7–2.7] or >140 mg/dl (OR = 1.9, 95% CI 1.5–2.5) even after adjustment for maternal age, parity and fetal sex.Conclusion: The 50 g GCT appears to be associated with a higher false positive rate and a lower positive predictive value in twin compared with singleton pregnancies.

Role of A1c in the postpartum screening of women with gestational diabetes

Objective: This study aimed to determine whether A1c detects a different prediabetes prevalence in women with a history of gestational diabetes mellitus (GDM) compared to those diagnosed with oral glucose tolerance test (OGTT) and the influence of haemoglobin concentrations on A1c levels.Design and patients: We evaluated carbohydrate metabolism status by performing OGTT and A1c tests in 141 postpartum women with prior GDM in the first year post-delivery.Results: The overall prevalence of prediabetes was 41.8%. Prevalence of isolated A1c 5.7–6.4%, impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) was 10.6%, 7.1%, and 9.2%, respectively. Isolated A1c 5.7–6.4% was associated with Caucasian origin (66.7% versus 32.6%, p = 0.02) and with higher LDL cholesterol concentrations (123 ± 28.4 mg/dl versus 101.6 ± 19.2 mg/dl, p = 0.037) compared with patients diagnosed by OGTT (IFG or IGT). Women with postpartum anaemia had similar A1c levels to those with normal haemoglobin concentrations (5.5% ± 0.6% versus 5.4% ± 0.4%, p = 0.237).Conclusions: Use of A1c in postpartum screening of women with GDM detected an additional 10.6% of patients with prediabetes and a more adverse lipid profile. Haemoglobin concentrations did not influence A1c values.

Characterization of the use of liraglutide for glycemic control in healthy and Type 1 diabetes mellitus suffering dogs

Glucagon-like peptide 1 (GLP-1) is a glucose-lowering, intestinal-derived factor with multiple physiological effects, making it attractive for diabetes therapy. However, the therapeutic potential of endogenous GLP-1 is limited, because of rapid inactivation by dipeptidyl peptidase-4. Recently, enhanced incretin preparations, such as liraglutide, have emerged, which are more resistant to degradation and longer lasting. Liraglutide is a long-acting acylated human GLP-1 receptor agonist, with a 97% amino acid sequence identity to endogenous human GLP-1, and 100% amino acid sequence homology with canine GLP-1.Since liraglutide has yet to be examined for use in dogs, and the incretin effect has been reported to exist in dogs, we sought to initially characterize liraglutide’s ability for glycemic control in healthy dogs, under an oral glucose tolerance test (OGTT) environment initially. This was followed up a more realistic scenario involving food with insulin injection +/− liraglutide injection resulting in a glucose curve based study involving dogs suffering from Type 1 diabetes mellitus (T1DM). Overall, liraglutide had a stabilizing effect on glucose levels, maintaining circulating levels between 77.0 and 137.0mg/ml throughout the OGTT test period, resulting in a significant reduction of 13.8% in glucose AUC0–120min (total area under the curve for 0–120min) as compared to baseline control in healthy dogs (n=5). Interestingly, the liraglutide associated reduction in circulating glucose was not accompanied by any significant increase in insulin. Moreover, T1DM dogs (n=4) responded favorably to liraglutide treatment, which lead to a significant reduction of 46.0% in glucose AUC0–12h (total area under the curve for 0–12h), and a significant reduction of 66.5% in serum glucose as compared to baseline controls (insulin treatment only). Therefore, liraglutide’s prandial glucagon suppressive ability appears to play a key role in its glucose-lowering capability, and offers great potential for use with dogs suffering from T1DM.

The effect of selective gut stimulation on glucose metabolism after gastric bypass in the Zucker diabetic fatty rat model

BackgroundPotential mechanisms underlying the antidiabetic effects of Roux-en-Y gastric bypass (RYGB) include altered nutrient exposure in the gut. The aim of this study was to evaluate the effects of selective gut stimulation on glucose metabolism in an obese diabetic rat model. MethodsSixteen male Zucker diabetic fatty rats were randomly assigned to 1 of 2 groups: RYGB with gastrostomy tube (GT) insertion into the excluded stomach or a control group with GT insertion into the stomach. An insulin tolerance test (ITT), oral glucose tolerance test (OGTT), and mixed meal tolerance test (MMTT) were performed before and 14–28 days after surgery. A glucose tolerance test via GT (GTT-GT) and MMTT via GT were performed postoperatively. ResultsPostoperatively, the RYGB group had significant decreases in weight and food intake. Both the ITT and OGTT tests revealed significantly improved glucose tolerance after RYGB. The GTT-GT showed a reversal of the improved glucose tolerance in the RYGB group. In response to meal stimulation, postoperatively, the RYGB group increased glucagon-like peptide 1 (GLP-1) secretion via the oral route and peptide YY secretion by both oral and GT routes. ConclusionWhen foregut exposure to nutrients was reversed after RYGB, the improvement in glucose metabolism was abrogated. This model can be extended to identify the role of gut in glucose homeostasis in type 2 diabetes.

Insulin Resistance in Dementia: A Comparison between Alzheimer's Disease and Frontotemporal Lobar Degeneration (P04.199)

Objective: Aim of the study was to compare plasma glucose concentrations and insulin resistance indices among patients with Alzheimer9s disease (AD), frontotemporal lobar degeneration (FTLD) and controls. Background Growing evidence suggests that insulin and glucose metabolism may contribute to cognitive impairment and neurodegeneration. Biological mechanisms underlying this association are still scantly known. Recent studies demonstrated that an impairment of central insulin signaling plays a key role in AD pathogenesis. Insulin sensitivity has not yet been investigated in patients with FTLD. Design/Methods: 21 AD patients (9 men, 12 women, mean age ± SD = 68.2 ± 9.5 yrs) and 16 FTLD patients (9 men, 7 women, mean age ± SD = 63.8 ± 7.3 yrs) were selected for the study and compared with a group of 21 controls. All patients underwent CSF measurement of T-tau, p-Tau and Aβ1-42. A 75 g oral glucose tolerance test (OGTT) was performed. Indices of beta cell function and insulin sensitivity (HOMA-IR, QUICKI, ISI-composite, ISI-Stumvoll and OGIS-180) were calculated. Results: During OGTT, glucose were significantly higher both in AD and FTLD than in controls. Plasmatic insulin levels were significantly reduced in AD patients compared with controls only at baseline and at 309, while in FTLD insulin concentrations were slightly increased. ISI-composite, HOMA-IR and OGIS-180 were significantly altered in AD patients compared to controls. ISI-Stumvoll and OGIS-180 indices were different in FTLD patients in comparison with controls. Conclusions: We found that glucose concentrations during the OGTT test and indices of insulin sensitivity were significantly impaired both in AD and FTLD patients. Intriguingly, plasmatic insulin concentration showed two different patterns in AD and FTLD, with an early impaired insulin secretion in AD and a delayed hyperinsulinemic response to glucose administration in FTLD. Our preliminary data supports the hypothesis that, in addition to AD, insulin resistance plays a role also in FTLD pathogenesis. Disclosure: Dr. Rainero has nothing to disclose. Dr. Rubino has nothing to disclose. Dr. Negro has nothing to disclose. Dr. Vacca has nothing to disclose. Dr. Govone has nothing to disclose. Dr. Giobbe has nothing to disclose. Dr. Pinessi has nothing to disclose.

Relationship between glycated albumin level and pancreatic β cell function in newly diagnosed type 2 diabetics

To explore the relationship between glycated albumin (GA) level and pancreatic β cell function in newly diagnosed type 2 diabetics. The subjects sought the confirmation of diabetes diagnosis or underwent diabetes screening tests in high-risk patients from January 2008 to October 2010. All of them underwent 75 g oral glucose tolerance test (OGTT) and insulin releasing test. The levels of GA and hemoglobin A1c (HbA1c) were analyzed by liquid enzymatic method and high performance liquid chromatography respectively. Homeostasis model assessment (HOMA) was used to evaluate the basal insulin resistance (HOMA-IR) and pancreatic β cell function (HOMA-β). ΔI30/ΔG30 was used to evaluate early-phase insulin secretion after a glucose load. (1) Among 500 type 2 diabetics according to the diagnostic criteria of WHO (1999), 279 were males and 221 were females. Average age was 56.3 ± 12.3, GA (21.1 ± 5.4)% and HbA1c (7.0 ± 1.3)%. (2) A significantly positive relationship was shown between HbA1c and GA (r = 0.691, P < 0.01). GA was also positively correlated with fasting plasma glucose (FPG), 0.5 hPG, 1 hPG, 2 hPG and 3 hPG after a glucose load of OGTT test (r = 0.511 - 0.627, P < 0.01). (3) GA was negatively correlated with body mass index (BMI) (r = -0.112, P < 0.01), HOMA-β (r = -0.350, P < 0.01) and ΔI30/ΔG30 (r = -0.263, P < 0.01). (4) Multivariant stepwise regression analysis showed that HbA1c, FPG, 3 hPG and ΔI30/ΔG30 were independent factors of GA level. Glycated albumin level is closely correlated with the function of early-phase insulin secretion in newly diagnosed type 2 diabetics.

Hemoglobin A1c for the diagnosis of diabetes: To replace or to guide oral glucose tolerance tests?

Aims/Introduction: To evaluate if hemoglobin A1c (A1C) can replace the use of the oral glucose tolerance test (OGTT) to diagnose diabetes in Chinese patients. Subjects without pre-existing diabetes were included in this community-based study. Each participant received a 75-g OGTT and A1C tests. A total of 1362 subjects, 512 men and 850 women, aged 18-88 years, were enrolled. The prevalence of diabetes was 7.4 and 7.3% by OGTT and by A1C ≥ 6.5% criteria, respectively. The optimal A1C cut-off for diabetes defined by OGTT was 6.1%. The performance of A1C ≥ 6.1% to find diabetes by OGTT was poor, with a kappa 0.50, sensitivity 80% and specificity 91%. Using current criteria of fasting plasma glucose (FPG) < 5.56 mmol/L to exclude and ≥7 mmol/L to diagnose diabetes (FPG criterion), the sensitivity, specificity and OGTT required were 77.2, 100 and 13.5%, respectively. Using A1C < 5.9% to exclude and ≥7.0% to diagnose diabetes (A1C criterion), the sensitivity, specificity and OGTT required were 89.1, 99.8 and 26.5%, respectively. However, using FPG < 5.56 mmol/L and A1C < 6.1% to exclude, and A1C ≥ 7.0% to diagnose diabetes (A1C plus FPG criterion), the sensitivity, specificity and OGTT required were 85.2, 100 and 18.9%, respectively. To screen for diabetes, the A1C criterion is more sensitive than the FPG criterion, with more OGTT needed. The A1C plus FPG criterion reduced the number of OGTT needed with acceptable sensitivity. A1C can guide, but cannot replace, OGTT to diagnose diabetes. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00181.x, 2011).

P241 Accuchek (TM) measurement of blood glucose correlates with true lab glucose measurement in children screened for cystic fibrosis related diabetes

BackgroundScreening for cystic fibrosis related diabetes (CFRD) is recommended as part of the cystic fibrosis annual review. For children over 10 an oral glucose tolerance test (OGTT) is recommended, but...

Selective breeding of mice for different susceptibilities to high fat diet-induced glucose intolerance: Development of two novel mouse lines, Selectively bred Diet-induced Glucose intolerance-Prone and -Resistant.

Aims/Introduction: The development of type 2 diabetes is primarily due to lifestyle and environmental factors, as well as genetics, as shown by familial clustering. To establish mouse lines for evaluating heritable factors determining susceptibility to diet-induced diabetes, we performed selective breeding for differences in high fat diet (HFD)-induced glucose intolerance. Selective breeding was performed using hybrid mice of C57BL/6J, C3H/HeJ and AKR/N backgrounds. After 5-week HFD feeding, mice showing high and low 2-h blood glucose levels in an oral glucose tolerance test (OGTT) were selected and bred over 14 generations to produce lines prone and resistant to diet-induced glucose intolerance (designated Selectively bred Diet-induced Glucose intolerance-Prone [SDG-P] and -Resistant [SDG-R]). At 5 weeks of age (pre HFD feeding), SDG-P mice showed higher blood glucose levels both in the OGTT and insulin tolerance test as compared to SDG-R mice. After receiving HFD, the glucose intolerance of SDG-P mice became more evident without hyper insulin secretion. In addition, SDG-P mice had greater body weight gain and lower HDL-cholesterol levels as compared to SDG-R mice. In comparison with C57BL/6J, a well-known strain prone to HFD-induced glucose intolerance, SDG-P mice showed significantly higher glucose levels in OGTT after the 5-week HFD feeding. Susceptibility to HFD-induced glucose intolerance was transmitted over generations and was intensified by selective breeding. The newly established mouse lines, SDG-P and SDG-R, may be useful in investigating the pathophysiology of type 2 diabetes through elucidating the crucial factors for determining the susceptibility to HFD-induced glucose intolerance. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00175.x, 2011).

Gestational diabetes mellitus (GDM) screening in morbidly obese pregnant women

ObjectiveTo study the outcomes of two-stage GDM screening of morbidly obese women in our obstetric unit and to evaluate the diagnostic performance of 20-week oral glucose tolerance test (OGTT) values in predicting or excluding late onset GDM. Study designA retrospective study in which 190 pregnant women with BMI ≥40 had two-stage screening: a 75g OGTT is performed at 20 weeks and repeated at 28 weeks if the 20-week OGTT was normal. Receiver operating characteristic (ROC) curves for 20-week OGTT values were constructed in order to obtain an optimal cut-off value of fasting and/or 2-h glucose at 20 weeks from which GDM could be predicted or excluded at 28 weeks. Sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were determined for each of the fasting and 2-h post-load glucose values at 20 weeks. ResultsForty six (24%) women were diagnosed with GDM. Thirty-two (70%) were diagnosed at 20 weeks and 14 (30%) at 28 weeks. The 2-h cut-off value of ≥6mmol/l at the 20-week OGTT had a negative likelihood ratio of 0.12 to predict GDM at 28 weeks. The low negative likelihood ratio reduces the probability of detecting GDM at 28 weeks from 9% (pre-test probability) to 1% (post-test probability). ConclusionNearly 70% of the women were diagnosed with GDM at 20 weeks, which gives an early opportunity to treat maternal hyperglycaemia with consequent health benefits. A 2-h cut-off glucose value of 6mmol/l at 20 weeks OGTT has a low negative likelihood ratio which virtually excludes GDM at 28 weeks. Hence women with a 2h value of <6mmol/l at 20 weeks can avoid a repeat 28 week OGTT test.

Is HbA 1c a good screening test for diabetes mellitus?

Objectives HbA 1c has been recently recommended as the primary diagnostic test for diabetes. This study evaluated the positive predictive value (PPV) and negative predictive value (NPV) of HbA 1c against the oral glucose tolerance test (OGTT) in three locations. Design and methods Three years of data with concurrent OGTT and HbA 1c tests were extracted from Laboratory Information Systems (LIS) and receiver operator (ROC) curves and positive and negative predictive values calculated comparing the OGTT with the HbA 1c values using a 10% prevalence of diabetes. Results The recommended threshold HbA 1c value of 6.5% did not give the optimal combination of NPV (0.93 to 0.92) and PPV (0.40 to 0.61) compared to a threshold HbA 1c value of 7.0% (NPV 0.91 to 0.92, PPV 0.61 to 0.73). Conclusion The optimal HbA 1c value for the diagnosis of diabetes is 7.0% but even at this HbA 1c the PPV is suboptimal and may cause up to 12% of patients without diabetes, as defined by a normal OGTT, to be classified having diabetes mellitus.