Diabetic Oral Glucose Tolerance Test Research Articles

1368-P: Carbohydrate Intake Is Associated with OGTT Levels in Pregnancy

Background: Traditionally, a carbohydrate-rich diet in the days preceding an oral glucose tolerance test (OGTT) has been recommended based on classic studies in non-pregnant individuals showing that carbohydrate restriction elevates post-load glucose levels. Instructions on carbohydrate intake given to pregnant women having an OGTT for gestational diabetes (GDM) diagnosis vary. We tested if self-reported carbohydrate intake in pregnancy is associated with OGTT results. Methods: Pregnant women (N=79) with ≥ 1 risk factor for GDM underwent a fasting 75 g OGTT at 24-30 wks gestation and completed a 24-hr dietary recall using a validated self-administered instrument. We tested for an association between carbohydrate intake in the 24 hrs preceding the OGTT and 1-hour OGTT glucose using linear regression, with adjustment for age, BMI, gestational age, race, and total caloric intake. We also tested for associations with 30-minute and 2-hour OGTT glucose and glucose area under the curve (AUC). Results: Women with lower carbohydrate intake (<median=235g) were slightly older (34 vs. 32 yrs, P=0.03), but otherwise similar to women with higher intake (BMI, history of GDM in a prior pregnancy, race/ethnicity, fasting glucose). We observed a graded linear relationship between carbohydrate intake and 1-hour OGTT glucose. For every 50 g reduction in carbohydrate intake, there was a 6.2 mg/dl increase in 1-hour OGTT glucose (β=6.2 mg/dl, P<0.01); this remained significant in the adjusted model (β=7.7 mg/dl, P=0.03). Lower carbohydrate intake was also associated with higher 30-minute (unadjusted β=4.4 mg/dl, P<0.01; adjusted β=6.7 mg/dl, P=0.02) and 2-hour OGTT glucose (unadjusted β=4.3 mg/dl, P=0.03; adjusted β=6.9 mg/dl, P=0.05) and glucose AUC (unadjusted β=513, P<0.01; adjusted β=683, P=0.03). Results did not change after excluding women with intake <1000 calories or when % carbohydrate intake was used as the predictor variable. Conclusion: Carbohydrate restriction or excess before an OGTT may affect the diagnosis of GDM. Disclosure E. Rosenberg: None. K. James: None. J. Arenas: None. M.J. Callahan: None. M. Cayford: None. S. Nelson: None. S.N. Bernstein: None. R. Thadhani: None. E.W. Seely: None. C.E. Powe: None. Funding National Institutes of Health (K23DK113218); Robert Wood Johnson Foundation; Harold Amos Medical Faculty Development Award (72456)

Abstract P441: Oral Glucose Tolerance Test Detects Diabetes at Early Stages

Introduction: Diabetes is a significant risk factor for cardiovascular disease (CVD) and one of the leading causes of death in the USA. The progression to type 2 diabetes, as the major type, is known to be gradual and remissible by intervention at early stages. However, despite the diabetes epidemic over the past few decades in the US, diabetes detection at the early stages has received insufficient attention. Assessing which diabetes diagnostic test can detect progression to diabetes at early stages may help to improve diagnostic recommendations for the at-risk population. Hypothesis: We hypothesize that the Oral Glucose Tolerance Test (OGTT) can detect diabetes at earlier stages compared with Hemoglobin A1c (HbA1c) and Fasting Plasma Glucose (FPG) tests. Therefore, the diabetes cases which are diagnosable only by OGTT have a better CVD risk profile. Methods: We extracted diabetes cases with laboratory evidence of diabetes OGTT ≥ 200 or FPG ≥ 126 or HbA1c ≥ 6.5% who reported themselves as undiagnosed by a doctor from the National Health and Nutrition Survey (NHANES) 2005-2014. We compared the CVD risk factors in the undiagnosed diabetes group between the subgroup, which was diagnosable only by OGTT and the subgroup, which was diagnosable by HbA1c or FPG. Results: Among the total of 953 undiagnosed diabetes cases (projected to 26.4 million) from NHANES 2005-2014, 207 (6.1 million, 23%) had a normal HbA1c and FPG, but OGTT ≥ 200. After adjustment for gender and race, the subgroup who were only diagnosable by OGTT had a better glycemic profile and considerably milder insulin resistance compared with the subgroup who were diagnosable by other diagnostic tests (table). Conclusions: The results indicate that OGTT can assess diabetes at earlier stages compared with HbA1c and FPG, providing opportunities for earlier preventive strategies.

Hyperglycemia affects global 5-methylcytosine and 5-hydroxymethylcytosine in blood genomic DNA through upregulation of SIRT6 and TETs

BackgroundAccumulating evidence suggests that epigenetic changes play key roles in the pathogenesis of type 2 diabetes mellitus (T2DM). However, the dynamic regulation of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) in diabetic peripheral blood DNA remains to be elucidated.ResultsWe collected fasting blood samples (104 patients and 108 healthy controls) and glucose-stimulated blood samples at different time points (11 patients and 5 healthy controls underwent oral glucose tolerance test (OGTT)), as well as blood samples from six couples of diabetic and control rats. A HPLC-MS/MS system was used for quantifying global 5mC and 5hmC in genomic DNA from white blood cells (WBCs), and qPCR was performed for detecting mRNA expression of SIRT6 and TETs. We found that global 5mC decreased, while global 5hmC increased in both patients and diabetic rats, with lower 5mC being a risk factor of T2DM (OR = 0.524, 95%CI 0.402–0.683, p = 1.64 × 10−6). The OGTT data from patients showed that 5mC declined within 1 h and then returned to the fasting status at 2 h, while 5hmC rose from 0.5 h to 3 h with increasing glucose. However, the similar patterns were not found in the controls. The mRNA expression of TET2, TET3, and SIRT6 was upregulated in patients (p = 0.012, p = 0.026, and p = 0.035, respectively). The similar results were observed in diabetic OGTT and rats. Correlation analysis indicated that SIRT6 was positively correlated with TET2 in humans (r = 0.277, p < 0.001) and rats (r = 0.942, p < 0.001), in addition to a correlation between glucose and SIRT6 (r = 0.162, p = 0.045) and TET2 (r = 0.174, p = 0.036).ConclusionsHyperglycemia appeared to promote the mRNA expression of SIRT6 and TETs, which in turn might cause the dynamic changes of 5mC and 5hmC in WBCs from T2DM patients.

Deletion distal to the PAX6 coding region reveals a novel basis for familial cosegregation of aniridia and diabetes mellitus

AimsAnalyze cosegregation of aniridia and diabetes to identify genetic criteria for detection and early treatment of diabetes-susceptible aniridia patients. MethodsWe assessed a two-generation family: three individuals with aniridia, two previously diagnosed as type 2 diabetes. One individual with aniridia, with unknown diabetes status, was evaluated by oral glucose tolerance test. Genetic analysis of aniridia-associated genes was performed on all available family members. Candidate genes were functionally tested by gene silencing in MIN6 pancreatic β-cells. ResultsA 25 year old male with aniridia had a diabetic oral glucose tolerance test despite a normal fasting blood glucose. A 484–630 kb deletion ∼120 kb distal to PAIRED BOX 6 (PAX6) showed dominant cosegregation with aniridia and diabetes in all affected family members. The deleted region contains regulatory elements for PAX6 expression and four additional coding regions. Knockdown of two of the deleted genes (Dnajc24 or Immp1l) with Pax6 impaired glucose-stimulated insulin secretion. ConclusionsWe demonstrate dominant cosegregation of diabetes and aniridia with a deletion distal to PAX6, which is clinically distinct from the mild glucose intolerance previously reported with PAX6 coding mutations. Asymptomatic aniridia individuals appear at risk of diabetes (and its complications) and could benefit from earlier diagnosis and treatment.

Rethinking the accuracy of 75 g glucose used in the oral glucose tolerance test in the diagnosis and management of diabetes

AimsWe investigated the specificity of the 75g oral glucose tolerance test (OGTT) and the clinical usefulness of the 2h post loading glucose (2h PLG) value in the clinical care of diabetes patients. MethodsThe 75g OGTT data of 1755 subjects were analyzed. The relationships and degrees of consistency among 2h PLG, fasting plasma glucose (FPG), and HbA1c values were assessed. We also investigated the degree of contribution of 2h PLG in the prescription of glucose-lowering agents and in the pitfall group for use of 75g OGTT. ResultsAmong 595 subjects with normal FPG, only 329 (55.3%) showed normal 2h PLG level, and 66 (11.1%) patients could be considered as having diabetes. Among 454 diabetes patients (based on FPG and HbA1c), 409(90.1%) showed 2h PLG values in the range of diabetes, 45 (9.9%) subjects did not exhibit diabetes. Pitfall group who used 75g OGTT for diagnosis diabetes (lower 2h PLG value compared to fasting and upper 2h PLG value compared to fasting) showed differences in body weight and height. ConclusionsBased on OGTT results, around 10% patients cannot be diagnosed with diabetes based solely on the 2h PLG value. Further studies on differences in glucose loading according to body weight, individual life pattern, and calorie requirement are needed for improvement of the specificity of the OGTT in the clinical management of diabetes.

Not performing an OGTT results in significant underdiagnosis of (pre)diabetes in a high risk adult Caucasian population.

Type 2 diabetes (T2DM) is known to be underdiagnosed. Tests for diagnosis include fasting plasma glucose (FPG), oral glucose tolerance test (OGTT) and HbA1c. HbA1c can be tested in non-fasting conditions. Therefore, general practitioners almost no longer execute OGTT's. We evaluated the performance of OGTT versus HbA1c in a population consisting of overweight and obese subjects, which can be considered a 'high risk' population. A total of, 1241 overweight and obese subjects without a history of diabetes (male/female: 375/866, age 44±13 years, body mass index 38.0±6.1 kg m-2) were tested for glucose tolerance status using FPG, OGTT and HbA1c. Exactly, 46.8% were found to have prediabetes and 11.9% were newly diagnosed with T2DM (male/female=18.9/8.9%) using ADA criteria. Testing only HbA1c would have resulted in 78 subjects being diagnosed with T2DM, but 47.3% of newly diagnosed patients would have been missed if OGTT would not have been done. Exactly 581 subjects were diagnosed with prediabetes, 1.4% subjects had impaired fasting glucose (IFG) 30.5% had impaired glucose tolerance (IGT), 5.1% subjects had a combined IFG+IGT, and 9.8% had an isolated elevated HbA1c (5.7-6.4%). Of the 581 subjects with prediabetes, 257 had an HbA1c <5.7%. Therefore, 44.2% subjects would have been missed when OGTT would not have been done. In a population with only overweight and obese adult subjects, 46.8% were diagnosed with prediabetes and 11.9% were newly diagnosed with diabetes. Exactly, 5.6 and 20.7% of total population met the diagnostic criteria of the OGTT for diabetes and prediabetes, respectively, but did not meet the diagnostic criteria of the HbA1c. These data suggest that not performing an OGTT results in significant underdiagnose of T2DM in an overweight and obese adult population.

Post-transplantation diabetes mellitus: evaluation of treatment strategies.

Post-transplantation diabetes mellitus (PTDM) is a serious complication after kidney transplantation, but evidence regarding long-term outcomes of treatment regimens remains scarce. The aim of this retrospective cohort analysis was to assess the long-term efficiency and safety of antidiabetic treatments in kidney transplant recipients (KTRs), who were diagnosed with PTDM by an oral glucose tolerance test (OGTT). Of 561 KTRs that were screened for PTDM at our outpatient clinic, 71 (13%) had a diabetic OGTT and were included in this study. Mean follow-up was 34.2 ± 16.1 months. Thirty-six PTDM patients (51%) received antidiabetic treatment after diagnosis with either a dipeptidyl peptidase-4 (DPP-4) inhibitor, a sulfonylurea, pioglitazone, or insulin. These patients had significantly higher fasting glucose and two-h plasma glucose (2HPG) values at baseline than those who remained without therapy. In contrast to lifestyle modification alone or sulfonylureas, DPP-4 inhibitors improved glycemic control significantly. Adverse events were generally mild and occurred at similar rates in all groups. While sulfonylureas failed to improve glycemic control, DPP-4 inhibitors appeared effective and safe for the therapy of PTDM after kidney transplantation.

HbA1c as a screening tool for cystic fibrosis related diabetes

AimsEarly diagnosis of cystic fibrosis (CF) related diabetes (CFRD) is important to improve outcomes. International guidelines recommend an oral glucose tolerance test (OGTT) for all CF patients aged ≥10years — this approach is controversial. The aim of this study was to develop an effective screening tool and reduce the need for a universal OGTT. MethodsAdult CF patients (without CFRD) attending an annual review assessment were recruited prospectively (March 2009–July 2012) into two sequential studies — a primary investigative study followed by validation study. All patients underwent an OGTT and were simultaneously screened by predetermined biochemical/clinical criteria to identify their risk of CFRD. A sensitivity/specificity analysis was performed using the World Health Organisation diabetes criteria as gold standard; modifications were made to improve the screening tool's accuracy and determine the optimal screening thresholds. This was tested in the validation study. Results429 patients (primary, n=94; validation, n=335: mean age=31.7±10.4(SD), 43% female, 77% on pancreatic supplements). Primary study: in predicting a positive OGTT, the test sensitivity was 66.7% and specificity 60%. HbA1c was carried over to the validation study as it was the most discriminative (optimal threshold ≥5.8% (40mmol/mol); receiver operating curve, ROC, score 0.60). Validation study: the number of patients with a normal, impaired and diabetic OGTT was 268(80%), 51(15.2%) and 16(4.8%), respectively. HbA1c provided a test sensitivity, specificity and ROC score of 93.8%, 53.0% and 0.73, respectively. ConclusionsThe use of HbA1c≥5.8%(40mmol/mol) is an effective tool for CFRD screening and reduced the need for an OGTT by 50.7%.

Glycated hemoglobin for the diagnosis of diabetes and prediabetes: Diagnostic impact on obese and lean subjects, and phenotypic characterization.

Aims/IntroductionMeasurement of glycated hemoglobin (HbA1c) has been recommended for the diagnosis of diabetes and prediabetes. However, epidemiological studies have shown significant discordance between HbA1c and glucose-based tests. Of the factors that could influence agreement between HbA1c and the oral glucose tolerance test (OGTT), bodyweight has not been fully evaluated. The aims of the present study were to evaluate the impact of HbA1c criteria to diagnose diabetes and prediabetes compared with OGTT, and to examine HbA1c in relation to body mass index.Materials and MethodsTwo cohorts were studied, one from an obesity clinic (n = 592) and one from subjects undergoing screening for diabetes (n = 462). All underwent OGTT and HbA1c measurement.ResultsIn the obese cohort, HbA1c ≥6.5% (≥48 mmol/mol) showed a sensitivity of 69.3% for diabetes, whereas HbA1c 5.7–6.4% (39–46 mmol/mol) did not identify prediabetes well (sensitivity 39.1%). In the diabetes screening cohort, HbA1c had low sensitivities for both diabetes (39.2%) and prediabetes (53.3%). When participants were stratified according to body mass index class I–III, HbA1c agreement with the OGTT for diabetes was much higher (80%, P < 0.005) in class I obesity compared with class II–III obesity; whereas for prediabetes, HbA1c had a low sensitivity in all obesity classes.ConclusionsThe agreement between HbA1c, fasting plasma glucose and 2-h glucose post-OGTT for the diagnosis of prediabetes was poor in our Italian population; whereas HbA1c ≥6.5% showed a relatively good agreement with OGTT for the diagnosis of diabetes. For the first time, we have shown that obesity class influences the diagnostic performance of HbA1c.

Evaluation of the antidiabetic and antioxidant potentials of methanolic leaf extract of Helianthus annuus L. on alloxan-induced hyperglycemic rats

Helianthus annuus (sunflower) is an annual plant native to America that possesses a large inflorescence. The present study evaluated the acute toxicity, antidiabetic, oral glucose tolerance test (OGTT), and antioxidant effects of methanol extract of H. annuus leaves using alloxan-induced diabetic rats. The extract at the dose range of 300–3,600 mg/kg was tolerated by the rats. The extract (150, 300, and 600 mg/kg) showed a significant (p 0.05) differences between the extract-treated groups and glibenclamide (2 mg/kg)-treated groups. At 6 h posttreatment, there was a significant (p 0.05) difference in blood glucose level among the treatment groups. In diabetic OGTT, the blood glucose level of the extract (600 mg/kg)-treated group was significantly (p 0.05) difference between the extract- and glibenclamide (2 mg/kg)-treated groups. The extract produced a concentration-dependent increase in antioxidant activity. These findings suggest that H. annuus has potent antidiabetic and antioxidant activities and validate its folkloric use in traditional medicine for the treatment of diabetes mellitus.

Unreliable oral glucose tolerance test and haemoglobin A1C in beta thalassaemia major – a case for continuous glucose monitoring?

Unreliable oral glucose tolerance test and haemoglobin A1C in beta thalassaemia major – a case for continuous glucose monitoring?

Prevalence and predictive factors of diabetes in hepatitis virus positive liver cirrhosis with fasting plasma glucose level of &lt;126 mg/dL

The aim of this study was to evaluate the prevalence and predictive factors of diabetes in hepatitis virus positive liver cirrhotic patients with fasting plasma glucose (FPG) level of <126 mg/dL. A total of 263 patients with hepatitis C virus (HCV) or hepatitis B virus (HBV) positive liver cirrhosis, FPG level of <126 mg/dL, and had diabetes status evaluated by the use of 75-g oral glucose tolerance test (OGTT), were enrolled in this study. Plasma glucose and insulin levels were analyzed periodically for 3 h after oral glucose loading. Diabetes was defined as a 2-h post-load glucose on the OGTT of ≥200 mg/dL. The prevalence of diabetes by use of OGTT and predictive factors for diabetes were evaluated by the use of the Mann-Whitney U-test, Fisher's exact probability test or multivariate analysis by logistic regression. Hypoalbuminemia was defined as serum albumin level of <3.9 g/dL. Elevated indocyanine green retention rate at 15 min (ICG( R) 15) was regarded as ≥ 25%. Out of 263 patients, 44 (16.7%) were diagnosed as having diabetes. Multivariate analysis showed that diabetes occurred when patients had hypoalbuminemia of <3.9 g/dL (odds ratio [OR] 2.33; 95% confidential interval [CI] = 1.04-5.24; P = 0.040) and ICG( R) 15 of <25% (OR 2.36; 95%CI = 1.01-5.58). Hypoalbuminemia and elevated ICG( R) 15 in hepatitis virus related cirrhotic patients with FPG level of <126 mg/day enhance diabetes pattern after OGTT with significant difference.

Comment on: Boronat et al. Differences in Cardiovascular Risk Profile of Diabetic Subjects Discordantly Classified by Diagnostic Criteria Based on Glycated Hemoglobin and Oral Glucose Tolerance Test. Diabetes Care 2010;33:2671–2673

We read with interest the article by Boronat et al. (1). In that article, individuals with discordant diabetes status by A1C and oral glucose tolerance test (OGTT) had their cardiovascular risk profile evaluated. Those who fulfilled the A1C-based criterion presented greater measures of BMI and waist circumference and lower values for HDL cholesterol than individuals with diabetic OGTT but A1C <6.5% (1). Both elevated A1C (2) and diabetes by OGTT (3) are associated with risks of cardiovascular disease and death compared with fasting glucose in observational studies. To further evaluate the findings by Boronat et al., we analyzed the risk profile of 693 participants (mean age 71.6 years; 39.5% men) from the Rancho Bernardo cohort who were categorized discordantly by …

Response to Comment on: Boronat et al. Differences in Cardiovascular Risk Profile of Diabetic Subjects Discordantly Classified by Diagnostic Criteria Based on Glycated Hemoglobin and Oral Glucose Tolerance Test. Diabetes Care 2010;33:2671–2673

We appreciate the efforts of Kramer and Araneta (1) to investigate whether our findings are reproducible in the Rancho Bernardo cohort. In apparent contrast to our results (2), they observed that subjects with diabetic oral glucose tolerance test (OGTT) but A1C <6.5% displayed a more unfavorable cardiovascular risk profile than subjects with A1C ≥6.5% (1). However, as noted by the authors, groups used for comparison in both studies were not homogeneous. All analyzed …

HbA1c in diagnosing and predicting Type 2 diabetes in impaired glucose tolerance: the Finnish Diabetes Prevention Study

We analysed the Finnish Diabetes Prevention Study data in order to evaluate how the new HbA(1c) -based criterion compares with the oral glucose tolerance test in diagnosing Type 2 diabetes among high-risk individuals during a prospective average follow-up of 4 years. In the Diabetes Prevention Study, 172 men and 350 women who were overweight and had impaired glucose tolerance at baseline were randomized into an intensive lifestyle intervention or a control group. The oral glucose tolerance test and HbA(1c) measurements were performed annually until the diagnosis of diabetes using the World Health Organization 1985 criteria. The sensitivity of the HbA(1c) ≥ 6.5% (≥ 48 mmol/mol) as a diagnostic criterion for Type 2 diabetes was 35% (95% CI 24%, 47%) in women and 47% (95% CI 31%, 64%) in men compared with diagnosis based on two consecutive oral glucose tolerance tests. The corresponding sensitivities for HbA(1c) ≥ 6.0% (≥ 42 mmol/mol) were 67% (95% CI 55%, 77%) and 68% (95% CI 51%, 82%). The participants with HbA(1c) ≥ 6.5% (≥ 48 mmol/mol) and diabetes based on the oral glucose tolerance test were more obese and had higher fasting glucose and 2-h glucose concentrations than those who had a diabetic oral glucose tolerance test but HbA(1c) < 6.5% (< 48 mmol/mol). There were no differences in the predictive performance of baseline fasting glucose, oral glucose tolerance test and HbA(1c) . Of those with diabetes diagnosis based on two oral glucose tolerance tests during the Diabetes Prevention Study follow-up, 60% would have remained undiagnosed if diagnosis had been based on HbA(1c) ≥ 6.5% (≥ 48 mmol/mol) criterion.

Differences in Cardiovascular Risk Profile of Diabetic Subjects Discordantly Classified by Diagnostic Criteria Based on Glycated Hemoglobin and Oral Glucose Tolerance Test

OBJECTIVETo characterize the cardiovascular risk profile of subjects categorized differently by A1C- and oral glucose tolerance test (OGTT)-based diagnostic criteria for diabetes according to the recommendations of the American Diabetes Association (ADA).RESEARCH DESIGN AND METHODSAn OGTT, A1C, and several cardiovascular risk factors were assessed in 964 individuals without known diabetes participating in a cross-sectional epidemiological survey in Gran Canaria, Spain.RESULTSTaking the OGTT as the gold standard, the sensitivity and specificity of an A1C value ≥6.5% were 38.7 and 99.6%, respectively. Subjects who fulfilled A1C-based criterion presented greater measures of BMI and waist circumference, lower values for HDL cholesterol, and higher values for fasting plasma glucose, homeostasis model assessment of insulin resistance, and fibrinogen than subjects with diabetic OGTT but A1C <6.5%.CONCLUSIONSNewly diagnosed diabetic individuals who fulfill A1C-based diagnostic criterion for the disease display a more unfavorable cardiovascular risk profile than individuals who only meet the glucose-based criteria.

Antioxidant and antihyperglycemic potential of methanolic extract of bark of Mimusops elengi L. In mice.

Ayurveda refers Mimusops elengi L. for the treatment of the diabetes. Considering the traditional claim of M. elengi in management of diabetes and the possible involvement of oxidative stress in pathogenesis of diabetes, the present study was aimed to evaluate the in vitro antioxidant and in vivo antihyperglycemic property of methanolic extract of bark of M. elengi (MEMeOH). In vitro antioxidant activity of MEMeOH was evaluated using reducing power assay, DPPH and hydroxyl radical scavenging assay. MEMeOH offered significant in vitro reducing power capacity and radical scavenging activity. In acute study in alloxan induced diabetes, MEMeOH exhibited significant (p< 0.001) antihyperglycemic effect. The onset of antihyperglycemic effect was observed at 2 nd hr; peak activity was demonstrated at 6 th hr. The antihyperglycemic effect of MEMeOH 400mg/kg, p.o. was persistent up to 24 th hr after drug administration. MEMeOH produced significant (p < 0.01) reduction in elevated glucose levels in glucose loaded non diabetic animals. The onset of action in non diabetic oral glucose tolerance test was found to be at 60 th min and peak activity was observed at 120 th min after oral glucose load. MEMeOH demonstrated significant (p < 0.01) reduction in elevated glucose levels 2hr before glucose administration and 6 hr after glucose load in oral glucose tolerance test in diabetic animals. MEMeOH has demonstrated antihyperglycemic activity in diabetic as well as non diabetic glucose loaded mice. MEMeOH should be further explored against diabetes and related complications.

Patients with cystic fibrosis and normoglycemia exhibit diabetic glucose tolerance during pulmonary exacerbation

Background Patients with cystic fibrosis and normoglycemia (CF-NGT) have higher but still “normal” glucose levels in the Oral Glucose Tolerance Test (OGTT). Respiratory exacerbation is associated with metabolic stress. The objective of this study was to assess the glucose metabolism and its relation to the steady state pulmonary function (FEV1) in patients with CF-NGT, specifically during pulmonary exacerbations (PE). Methods CF-NGT patients who were not on steroids, underwent OGTT and intravenous glucose tolerance tests (IVGTT) during PE and 4 weeks after complete recovery. Results Of the ten recruited patients two had diabetic OGTT and were excluded. The remaining normoglycemic patients displayed during PE a diabetic glucose tolerance with mean glucose levels of 233 ± 8 and 262 ± 11 mg/dl at 90 and 120 min respectively, compared with normal levels of 154 ± 21and 126 ± 20 mg/dl ( p < 0.002) during the steady state. IVGTT showed a tendency to higher first phase insulin release during PE compared with the steady state.(min 3; 305 ± 80 vs. 216 ± 40 pmol\\l p = 0.075). Finally, when relating the diabetic status to the general respiratory function we found a negative correlation between baseline FEV1 and glucose levels at 2 h after OGTT during PE ( r = − 0.88, p = 0.002). Conclusion In this pilot study we show that during PE patients with CF and normal glucose tolerance exhibited early latent diabetic glucose intolerance. As this hyperglycemia presents in the later parts of the OGTT it probably results from insufficient second phase insulin secretion during PE. The negative correlation observed here between the diabetic glucose tolerance and FEV1 indicate the need of interventional studies using insulin during PE in non-diabetic patients to determine its potential benefit on the outcome from recurrent PEs.

Undiagnosed diabetes in kidney transplant candidates: a case-finding strategy.

Guidelines recommend that candidates for kidney transplantation (KTx) who do not have diabetes perform a pretransplantation oral glucose tolerance test (OGTT) when fasting plasma glucose (FPG) is <110 mg/dl (<6.1 mmol/L); however, the OGTT is potentially costly and cumbersome. We studied the role of the OGTT for diagnosing diabetes and the accuracy of FPG and glycated hemoglobin (HbA(1c)) for predicting a diabetic OGTT before KTx. In this cross-sectional study, 889 first single-kidney transplant candidates without diabetes, mainly white, performed an OGTT during the transplantation workup. Results were studied using receiver operating characteristic analysis. Of 72 (8.1%) patients with undiagnosed diabetes, only 16 (22%) had a diabetic FPG (> or =126 mg/dl [> or =7.0 mmol/L]). In patients with a nondiabetic FPG, diabetes (2-hour plasma glucose [2h-PG] > or =200 mg/dl [> or =11.1 mmol/L]) was predicted by FPG but not by HbA(1c). Performing the OGTT in patients with FPG 92 to 125 mg/dl (5.1 to 6.9 mmol/L) identified 65 (90%) patients with diabetes (16 by FPG, 49 by 2h-PG) and required seven OGTTs per patient identified. Subjecting all patients with FPG <110 mg/dl (<6.1 mmol/L) to the OGTT identified 60 (83%) patients with diabetes (16 by FPG, 44 by 2h-PG) but required 14 OGTTs per patient. The OGTT was paramount in finding most cases of undiagnosed diabetes before KTx. FPG but not HbA(1c) predicted a diabetic OGTT. We suggest that white KTx candidates without diabetes perform a pretransplantation OGTT when FPG is 92 to 125 mg/dl (5.1 to 6.9 mmol/L).

Assessing the risk of post-transplantation diabetes mellitus with an oral glucose tolerance test

This Practice Point commentary discusses the findings of a prospective study by Kuypers et al. that was designed to determine the best clinical diagnostic tool for identifying patients at risk of developing post-transplantation diabetes mellitus (PTDM) following renal transplantation. Fasting plasma glucose (FPG) levels on the day of transplantation and FPG levels and an oral glucose tolerance test (OGTT) at 5 days after transplantation were evaluated in de novo renal transplant recipients. The predictive values of these tests were assessed alongside other known risk factors for PTDM. A normal (vs diabetic) OGTT on day 5 was associated with a significantly reduced risk for PTDM (odds ratio 0.03; P = 0.0002). A similar reduction in the risk of PTDM was conferred by normal FPG levels on day 5 (odds ratio 0.06; P <0.0001). While the OGTT or FPG test at 5 days after transplantation might prove to be useful predictive diagnostic tools for the development of PTDM, studies that incorporate baseline evaluation of pre-existing glucose metabolic disorders are needed.