Abnormal Oral Glucose Tolerance Test Results Research Articles

Utilization of a Postpartum Fasting Blood Glucose to Predict Impaired Glucose Tolerance in Patients with Gestational Diabetes Mellitus.

The Endocrine Society recommends a postpartum fasting blood glucose (FBG) be performed for patients with gestational diabetes mellitus (GDM) prior to hospital discharge to screen for ongoing hyperglycemia. There are limited data, however, on whether an FBG can screen for glucose intolerance and if it correlates with the gold standard 4- to 12-week 2-hour oral glucose tolerance test (OGTT). Our objective was to evaluate if FBG correlates with the gold standard 2-hour OGTT. This retrospective cohort study of patients with GDM who delivered >20 weeks' gestation at two urban centers from January 2017 to December 2020 included those who completed both a postpartum FBG prior to discharge and a 2-hour 75-g OGTT within 1 year of delivery. Abnormal 2-hour OGTT was defined as fasting value ≥100 mg/dL and/or 2-hour value ≥140 mg/dL. We evaluated test characteristics (e.g., sensitivity, specificity) of postpartum FBG cut-offs to predict an abnormal 2-hour OGTT result. A total of 235 patients met inclusion criteria, of which 63% were diet-controlled and 37% required medical management. FBG ranged from 64 to 134 mg/dL, with 6/235 (2.6%) with values ≥126 mg/dL. A total of 39/235 (16.6%) of patients had an abnormal 2-hour OGTT. Overall, area under the curve for FBG predicting abnormal 2-hour OGTT was 0.65. Traditionally considered high cut-offs (≥126 mg/dL) for predicting persistent impaired glucose intolerance demonstrated poor positive predictive value (PPV; <20%). In contrast, low cut-offs demonstrated excellent NPV (>90%). A postpartum FBG of 88 mg/dL was determined to be the optimal cut-off for FBG with NPV = 92.4% (Youden index = 0.34). In this dataset, if FBG ≥ 88 mg/dL was used to determine if 2-hour OGTT was required, almost half of GDM patients could avoid further glucose tolerance testing. While previously thought of as best utilized for its PPV, the FBG may be best used for its NPV. In our study, clinical application of an FBG < 88 mg/dL was highly correlative with a normal 2-hour OGTT. · Screening for postpartum glucose intolerance is essential for gestational diabetes.. · A promising initiative includes offering screening tests while in the hospital, including an FBG.. · Application of a postpartum FBG < 88 mg/dL is highly correlative with a normal 2-hour OGTT..

Endothelial Dysfunction Is Associated with Decreased Nitric Oxide Bioavailability in Dysglycaemic Subjects and First-Degree Relatives of Type 2 Diabetic Patients.

Oxidative stress plays an important role in the pathogenesis of diabetes. We investigated oxidative stress and nitrite/nitrate concentrations at baseline and during postprandial hyperglycaemia in 40 first-degree relatives (FDRs) of diabetic patients with normal oral glucose tolerance test (OGTT) results, 40 subjects with abnormal OGTT results (dysglycaemic) and 20 subjects with normal OGTT results (normoglycaemic). Malondialdehyde (MDA), protein carbonyls (PCs), nitrite/nitrate plasma levels, the perfused boundary region (PBR—Glycocheck) of the sublingual microvessels, a marker of glycocalyx integrity, coronary flow reserve (CFR) and left ventricular global longitudinal strain (GLS) were assessed at 0 and 120 min of the OGTT. Insulin sensitivity was evaluated using Matsuda and the insulin sensitivity index (ISI). In all subjects, there were no significant changes in MDA or PC after the OGTT (p > 0.05). Compared with normoglycaemic subjects, FDRs and dysglycaemic subjects had significantly decreased nitrite/nitrate levels (−3% vs. −24% vs. −30%, respectively), an increased PBR and reduced CFR and GLS at 120 min (p < 0.05). The percent reduction in nitrite/nitrate was associated with abnormal Matsuda and ISI results, reversely related with the percent increase in PBR (r = −0.60) and positively related with the percent decrease in CFR (r = 0.39) and GLS (r = 0.48) (p < 0.05). Insulin resistance is associated with reduced nitric oxide bioavailability and coronary and myocardial dysfunction in FDRs and dysglycaemic subjects.

Repeated oral glucose tolerance tests in women at risk for gestational diabetes mellitus

ObjectivePregnant women with a negative oral glucose tolerance test (OGTT) between 24–28 weeks as part of risk-based screening for gestational diabetes mellitus (GDM) may develop clinical signs or symptoms suggestive for GDM in the third trimester. We aimed to determine the additional yield of repeating an OGTT to detect missed GDM in this group and assess patient characteristics and indications associated with a positive second OGTT. Study designWe conducted a retrospective cohort study of women with a negative OGTT between 24–28 weeks of pregnancy in two hospitals in the Netherlands. Patient characteristics, pregnancy outcomes, OGTT results and indications were compared between women with normal (non-GDM) and abnormal (GDM) results of the second OGTT, using the WHO 1999 criteria (fasting glucose ≥7.0 mmol/L or 2 -h post load ≥7.8 mmol/L). We used receiver operating characteristic (ROC) curve analysis to determine cut-offs for fasting and 2 -h glucose values of the index OGTT that were associated with a positive OGTT in the third trimester. ResultsOf 3147 women at risk for GDM, 183 underwent a second OGTT in the third trimester following their regular OGTT at 24–28 weeks. In 43 women (23.5%) GDM was diagnosed based on the second OGTT. A history of GDM was associated with subsequent GDM diagnosis, with an odds ratio of 2.6 (95% CI 1.0–6.3). Both fasting and 2 -h post load glucose values of the index OGTT were significantly higher in women with abnormal OGTT results later in pregnancy. Index OGTT glucose value cut-offs of 4.8 mmol/L (fasting) and 6.5 mmol/L (2 -h) had positive predictive values of 0.32 and 0.47 for a positive OGTT in the third trimester, and negative predictive values of 0.83 and 0.90, respectively. Fetal growth as a clinical symptom for GDM was the most frequent indication for repeating the OGTT, resulting in the diagnosis of GDM in 22.7% of women tested for this indication. ConclusionRepeating an OGTT after initial negative screening results in additional GDM diagnoses. In case of clinical signs, especially in women with additional risk factors such as a history of GDM or higher index OGTT glucose values, repeating an OGTT could be considered.

Association of glucose levels in pregnancy with use of health care services

AimsTo determine whether women with abnormal gestational diabetes (GDM) screening test results short of frank GDM have increased health-services utilization compared to women with normal results. MethodsWe conducted a retrospective-cohort study among 29,999 women enrolled in Kaiser Permanente Northwest who completed GDM screening (two-step method: 1-h, 50-g glucose-challenge test (GCT); 3-h, 100-g oral-glucose-tolerance test (OGTT)). Test results were categorized as normal GCT (referent, n = 25,535), normal OGTT (n = 2246), abnormal OGTT but not GDM (n = 1477), and GDM (n = 741). Rate ratios (RRs) were calculated for utilization measures and analyses were age- and BMI-adjusted. ResultsCompared to women with normal GCT, rates for obstetrical ultrasound, noninvasive and invasive antenatal testing, and ambulatory visits to the obstetrics department were significantly greater among women with abnormal OGTT (RRs 1.2 [95%CI 1.1, 1.4], 1.3 [1.1, 1.4], 1.7 [1.3, 2.3], and 1.1 [1.1, 1.1], respectively) and GDM (RRs 1.8, 1.8, 2.0, and 1.3, respectively). Women with abnormal OGTT results were more likely to visit a dietician than women with normal GCT; RRs ranged from 4.0 [3.3, 4.9] for women with abnormal GCT but normal OGTT to 72.1 [64, 81] for women with GDM. ConclusionsHealth-services utilization increased with severity of glucose result, even among women without GDM.

Inflammatory bowel disease (IBD) in horses: a retrospective study exploring the value of different diagnostic approaches

BackgroundDiagnosing IBD in horses is challenging and requires a multimodal approach, since no conclusive diagnostic test is available.The objectives of this study were to provide an overview of population characteristics, results of applied diagnostic tests, treatment modalities and outcome in a large group of horses thought to have IBD and that were presented to four large equine referral hospitals, and to provide an exploratory investigation of possible associations between results of applied diagnostic tests, applied treatment modalities and outcome.A retrospective case series was performed across four large equine referral hospitals. Seventy-eight horses, thought to have IBD were included. Case history, clinical findings, diagnostic test results including oral glucose tolerance test (OGTT) and enteral biopsies (both duodenal and rectal), applied therapy and outcome were studied. A Chi-Square test was used to identify associations between results of diagnostic tests, treatment and outcome. P-values < 0.05 were considered significant.ResultsLethargy, diarrhoea, recurrent colic and weight loss were recorded in respectively 21,8%; 14,1%; 28,2% and 78,2% of cases. Over 70% of horses thought to have IBD had an abnormal OGTT. Only weight loss was significantly associated with aberrant enteral biopsy results, but not with abnormal OGTT results or low blood total protein. There was no association between an aberrant biopsy result and a disturbed OGTT. There was no association between either OGTT results or enteral biopsy results and a low blood total protein content, presence of gastric ulcer disease or an aberrant endoscopic aspect of the duodenal entrance.ConclusionsWeight loss is a highly prevalent symptom in IBD suspected horses. Enteral biopsies may be a useful diagnostic aid in the work-up of horses thought to suffer from IBD, however further research is required to demonstrate their true diagnostic value. Until more standardized scientific research is available, one should be careful with the interpretation of enteral biopsy results There is a need for better standardization of enteral biopsy procedures and the histopathological scoring of biopsies.

The use of fructosamine in cystic fibrosis-related diabetes (CFRD) screening

ObjectiveTo determine whether serum fructosamine correlates with glycemic control and clinical outcomes in patients being screened for cystic fibrosis-related diabetes (CFRD). MethodsFructosamine and percent predicted forced expiratory volume in 1s (FEV1) were measured in patients undergoing a 2h oral glucose tolerance test (OGTT) for CFRD screening. Fractional serum fructosamine (FSF) was calculated as fructosamine/total protein. ResultsFSF exhibited a positive correlation with 2h OGTT results (r2=0.3201, p=0.009), and ROC curve analysis suggested that FSF can identify patients with an abnormal OGTT (AUC=0.840, p=0.0002). FSF also exhibited a negative correlation with FEV1 (r2=0.3732, p=0.035). Patients with FSF≥3.70μmol/g had significantly lower FEV1 (median 47%) compared to those with FSF<3.70μmol/g (median 90%; p=0.015). ConclusionsFSF correlated with both OGTT results and FEV1, and reliably identified patients with abnormal OGTT results. This simple blood test shows potential as an effective tool in CFRD screening.

Prospective evaluation of abnormal glucose metabolism and insulin resistance in patients with atypical endometrial hyperplasia and endometrial cancer.

Obesity and diabetes (DM) are known to increase the risk of endometrial cancer (EC). However, little is known about the prevalence of abnormal glucose metabolism and insulin resistance (IR) in EC patients. We aimed to evaluate the prevalence of abnormal glucose metabolism and IR in EC patients. We prospectively enrolled atypical endometrial hyperplasia (AEH) and EC patients who had received planned treatment at Chiba University Hospital, Japan. All patients, except those with a confirmed diagnosis of DM, underwent the 75-g oral glucose tolerance test (OGTT) before treatment. We evaluated the prevalence of obesity, defined as body mass index (BMI) ≥25, IR, abnormal glucose metabolism, and the associations between these three factors and the clinical characteristics of AEH and EC patients. We enrolled 279 patients from April 2009 to March 2015. Of these, 56 had a confirmed diagnosis of DM. Abnormal OGTT results, including impaired fasting glucose (n=7), impaired glucose tolerance (n=69), and newly identified DM (n=33), were noted in 109 patients. Obesity, IR, and abnormal glucose metabolism were observed in 49.8, 51.6, and 59.1% of patients, respectively. Abnormal glucose metabolism was significantly associated with age (P<0.001), body mass index (P=0.004), and IR status (P<0.001) in multivariate analysis. Abnormal glucose metabolism, IR, and obesity were highly prevalent in patients with AEH and EC. These results indicate that physicians should consider a patient's metabolic status in the postoperative management of AEH and EC patients.

Identification of severe gestational diabetes mellitus after new criteria used in China

To evaluate the way to identify severe gestational diabetes mellitus (GDM) according to the Ministry of Health (MOH) criteria associated with high risk of adverse pregnancy outcomes. Medical records of 9803 pregnant women attending Peking University First Hospital were analyzed retrospectively. Participants diagnosed as GDM were divided into different groups according to the different number of oral glucose tolerance test (OGTT) results and the prepregnancy body mass index (BMI). Participants without GDM were included in group N. The incidence of adverse pregnancy outcomes was analyzed according to incremental differences in prepregnancy BMI and the number of abnormal OGTT result. (1) There were 21.8% (2133/9803) women diagnosed as GDM. (2) The frequency of large for gestational age in group 2 (GDM with 2 or more abnormal OGTT value; 21.6%) was significantly higher than group 1 (GDM with only 1 abnormal OGTT value; 16.8%) and group N (13.2%), and there was also significant difference between group 1 and group N. (3) Risk of adverse pregnancy outcomes in GDM would be increased in women with prepregnancy body mass index ⩾24 kg m(-2) in GDM. (4) Women with BMI <24 kg m(-2) in group 1 have low risk of adverse pregnancy outcomes and seldom need insulin (1.3%) in pregnancy. (5) There were 1142 cases (53.5%) of severe GDM in this study and 991 cases (46.5%) of mild GDM. GDM women with ⩾2 abnormal OGTT values or only 1 abnormal OGTT value but with prepregnancy BMI ⩾24 kg m(-2) should be recognized as severe GDM. We should pay more attention to and treat selectively with the severe GDM, especially in rural areas.

Influence of medical nutrition therapy on borderline glucose intolerance in pregnant Taiwanese women

Objective: To investigate the influence of medical nutrition therapy (MNT) on borderline glucose intolerance (BGI) in pregnant Taiwanese women.Methods: A total of 5194 singleton pregnant women were enrolled in this prospective, non-randomized study. The participants were subjected to the 50 g 1-h glucose challenge test (GCT) and 100 g 3-h oral glucose tolerance test (OGTT) to screening gestational diabetes mellitus (GDM). BGI was defined as a positive GCT and normal OGTT results. GDM was defined as a positive GCT and abnormal OGTT results. The women were categorized into the following groups: (1) GCT-negative, n = 3881; (2) BGI with MNT, n = 273; (3) BGI without MNT, n = 712; and (4) GDM, n = 328. Multiple logistic analyses were used to estimate the risks of pregnancy outcomes.Results: The odds ratios (95% confidence interval) for total cesareans, third- or fourth-degree perineal lacerations, gestational hypertension or preeclampsia and macrosomia were 1.24 (1.04–1.49), 1.55 (1.06–1.28), 1.78 (1.21–2.61) and 2.50 (1.28–4.91) in the BGI without MNT group compared to the GCT-negative group. There was no difference between BGI with MNT and GCT-negative groups.Conclusions: Women with BGI who did not receive MNT had increased risks of adverse pregnancy outcomes, whereas who received MNT had no different risk with GCT-negative women.

928P - Prospective Evaluation of Glucose Tolerance and Insulin Resistance Among Patients with Endometrial Cancer and Atypical Endometrial Hyperplasia

ABSTRACT Aim: Obesity and diabetes mellitus (DM) increase the risk of endometrial cancer (EC). However, the prevalence of insulin resistance (IR) and DM, including pre-DM, among Japanese patients with EC remains unclear. This study aimed to evaluate the prevalence of IR and DM, including pre-DM, among Japanese patients with EC, as well as their associations with clinical characteristics. Methods: We prospectively enrolled patients with atypical endometrial hyperplasia (AEH) and EC who received planned treatment at Chiba University Hospital. All patients, except those with a confirmed diagnosis of DM, underwent the 75-g oral glucose tolerance test (OGTT) before treatment. IR was defined as a history of DM or a homeostasis model assessment of insulin resistance score ≥ 2.5. We compared the metabolic status of patients with type I (AEH, and endometrioid grade 1 and grade 2) and type II (endometrioid grade 3, serous carcinoma, and clear cell carcinoma) patients as well as premenopausal and postmenopausal patients. Results: We enrolled 216 patients from March 2009 to February 2014. Among these 216 patients, 36 had a confirmed diagnosis of DM. Other than these 36 patients, abnormal OGTT results were noted in 85 patients. IR was observed in 47% of patients. A total of 161 patients (75%) had risk factors of EC such as DM/pre-DM, IR or obesity. Premenopausal patients were more frequently obese and more frequently exhibited IR than postmenopausal patients (68% versus 40%, p Conclusions: DM, including pre-DM, IR, and obesity were found to be highly prevalent in patients with EC and AEH. These results may support that the management of metabolic status is important for improving the survival of these patients. Disclosure: All authors have declared no conflicts of interest.

Effects of gestational malnutrition on glucose and lipid metabolism of pregnant rats and birth weight of their offsprings

Objective To explore the glucose and liplid metabolism changes of pregnant rats and the birth weight of their offsprings due to pregnancy malnutrition,including overnutrition and undernutrition.Methods Thirty pregnant Wistar rats were randomly divided into three groups on the day of conception,the high-fat-diet group,normal control group and 50％ food-restricted diet group.Increase of body weight and serum level of triglycerides,high-density lipoprotein,low-density lipoprotein,oral glucose tolerance test (OGTT) and insulin release test(IRT) levels during pregnancy were measured.The birth weight of offsprings was recorded within 12 h after birth.One-way ANOVA,LSD or Dunnett T3,and Chi-square test were applied for statistical analysis.Results The body weight at late pregnancy and the level of triglycerides and low-density lipoprotein were significantly increased in the high-fat-diet rats compared to normal control ones [(1.68±0.13) mmol/L vs (0.78±0.08) mmol/L,(0.57±0.04) mmol/L vs (0.35±0.07) mmol/L; both P＜0.01].While the level of high-density lipoprotein of high-fat-diet rats was lower than that of the normal control rats [(0.56±0.06) mmol/L vs (1.09±0.08) mmol/L,P＜0.05].The level of triglycerides,low density lipoprotein and high density lipoprotein in 50％ food restricted group [(0.47±0.06) mmol/L,(0.21±0.06) mmol/L and (0.42±0.05) mmol/L] were lower than the control group (all P＜0.05).Impaired glucose tolerance,abnormal OGTT and IRT results were found in both high-fat-diet and 50％ foodrestricted diet rats.The fasting plasma glucose level in high-fat-diet group was significantly increased in late pregnancy compared to the control [(6.63±0.53) mmol/L vs (4.90±0.26) mmol/L,P＜0.05],while there was no significant difference between rats in 50％ food-restricted diet [(4.18±0.26) mmol/L]and control group (P＞0.05).There was no statistical difference in fasting serum insulin level among the three groups.The average birth weight was significantly increased in high-fat-diet rats than in the control group [(6.14±0.31) g vs (5.73±0.26) g,P＜0.05],and the incidence of macrosomic newborn rats in the high-fat-diet group was also higher than that of the control group [19.2 ％ (19/99)vs 7.84％(8/102),P＜0.05].The birth weight of offspring in 50％ food-restricted diet group was decreased with their average birth weight of (4.54±0.23) g,which was lower than that of the control group (P＜0.05).The incidence of macrosomic [13.40％ (11/76)] and low birth weight newborn rats [15.90％ (13/76) vs 3.92％(4/102)] in food-restricted diet group were both higher than in the control group (P＜0.05); and smaller number of offsprings was obtained than the control group (76 vs 102,P＜0.05),the number of offsprings in high-fat-diet group was 99,which was less than the control group without statistical difference (P＞0.05).Conclusions Pregnancy malnutrition,including overnutrition and undernutrition,may affect the lipid metabolism and glucose tolerance of pregnant rats,leading to insulin resistance,and may also contribute to the abnormal birth weight of the offspring,including macrosomia and low birth weight. Key words: Pregnancy complications; Malnutrition; Glucose metabolism disorders; Lipid metabolism disorders; Fetal macrosomia; Infant, low birth weight; Disease models, animal

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?

Inclusion of Educational Messages in Laboratory Reports Aids to Complete the Diagnostic Workup of Hyperglycemia

To evaluate whether educational messages regarding oral glucose tolerance test (OGTT) indications in laboratory reports increase the number of OGTTs appropriately requested. The following message was printed on the lab reports of individuals with a fasting plasma glucose (FPG) concentration between 5.5 and 6.9 mmol/l: "A FPG between 5.5 and 6.9 mmol/l is considered abnormal by the American Diabetes Association (impaired fasting glucose). An OGTT is recommended if the patient does not have a diagnosis of diabetes and suffers from conditions associated with an increased risk for having type 2 diabetes (i.e., overweight, high blood pressure, abnormal plasma lipids or family history of diabetes)." The number of educational messages printed was 81,099. The intervention resulted in a significant increase in the number of OGTTs requested, from 78 +/- 19 to 268 +/- 48 tests per month. It also resulted in a greater proportion of case subjects that had an abnormal OGTT result. Educational messages in laboratory reports aid in the diagnostic workup of hyperglycemia.

Modestly Elevated Glucose Levels During Pregnancy Are Associated With a Higher Risk of Future Diabetes Among Women Without Gestational Diabetes Mellitus

To determine whether 1-h oral glucose challenge test (OGCT) or 3-h oral glucose tolerance test (OGTT) results below gestational diabetes mellitus (GDM) criteria are associated with developing diabetes. A retrospective cohort study was performed among women without GDM who had a pregnancy OGCT (n = 24,780) or OGTT (n = 6,222). Subsequent diabetes was ascertained by ICD-9 codes or pharmacy or laboratory data over a median follow-up of 8.8 years. Diabetes risk increased across OGCT quartiles: adjusted hazard ratio (HR) 1.67 (95% CI 1.07-2.61) for 5.4-6.2 mmol/l, 2.13 (1.39-3.25) for 6.3-7.3 mmol/l, and 3.60 (2.41-5.39) for >or=7.4 mmol/l compared with <or=5.3 mmol/l. Women with one abnormal OGTT result had a higher risk compared with those with normal values (HR 2.08 [95% CI 1.35-3.20]). Women with modestly elevated glucose levels below the threshold for GDM had a higher risk for diabetes.

HbA1c predicts the likelihood of having impaired glucose tolerance in high-risk patients with normal fasting plasma glucose

Although the oral glucose tolerance test (OGTT) is the 'gold standard' for diagnosing prediabetes/diabetes, it is inconvenient for the patient and time consuming. The only alternative simple screening test is fasting plasma glucose (FPG). FPG concentrations of > 6.0 mmol/L represent prediabetes/diabetes. FPG concentrations of < or = 6.0 mmol/L may be considered 'normal', although some such patients will demonstrate abnormal glucose tolerance when subjected to an OGTT. We have evaluated the use of glycated haemoglobin (HbA1c) as a screening test for diabetes or impaired glucose tolerance (IGT) in patients who have risk factors for diabetes but FPG < or = 6.0 mmol/L. A total of 580 patients with at least two risk factors for diabetes underwent an OGTT and HbA1c measurement. In all, 225 patients had a FPG < or = 6.0 mmol/L and met the inclusion criteria. Of these, 23.1% (n=52) had an abnormal OGTT result (45 had IGT and 7 had diabetes). Subjects with abnormal glucose tolerance had a higher percentage of HbA1c than subjects with normal glucose tolerance (P<0.001). An HbA1c of 5.6% gave an optimal sensitivity of 72% and specificity of 77% to predict a 2 h plasma glucose > or = 7.8 mmol/L. The use of FPG concentration followed by selective measurement of HbA1c in patients who are at high risk of developing diabetes may represent a reasonable approach to identifying patients requiring an OGTT.

Elevated plasma homocysteine levels in gestational diabetes mellitus

Objective. This prospective study investigated the occurrence of hyperhomocysteinemia in a population of patients with gestational diabetes. The aim was to determine whether elevated plasma homocysteine is associated with gestational diabetes in Turkish women. Study design. This prospective controlled study was conducted in the Department of Obstetrics and Gynecology of the Baskent University Faculty of Medicine between April 2002 and June 2003, and involved 304 Turkish women with uncomplicated pregnancies who were at 24-28 weeks gestation. The women in the study were assigned to one of three groups according to the results of the 50-g glucose screening and the oral glucose tolerance test (OGTT): group 1 comprised women who had normal glucose levels (≤ 135 mg/dL) after the 50-g challenge; group 2 comprised women with abnormal screening test results (> 135 mg/dL) but normal OGTT results; and group 3 comprised patients with gestational diabetes mellitus (GDM) according to the OGTT. Levels of fasting glucose...

Insulin action enhancement normalizes brachial artery vasoactivity in patients with peripheral vascular disease and occult diabetes

Purpose: Brachial artery vasoactivity (BAVA) evaluation is a reliable, noninvasive method of assessing arterial endothelial function in vivo. We previously have shown that patients with peripheral vascular disease (PVD) and occult diabetes have abnormal BAVA results when fasting and after oral glucose intake during oral glucose tolerance test (OGTT). Troglitazone is an oral hypoglycemic agent that enhances the action of insulin. The effect of troglitazone on BAVA in patients with occult diabetes and PVD is not known. Methods: Patients with PVD, normal fasting glucose levels, and abnormal OGTT results were identified. With a duplex ultrasound scan, BAVA was evaluated by measuring the brachial artery (BA) flow (in millimeters per minute) before and after 5 minutes of BA occlusion during fasting and at 30 minutes, 1 hour, and 2 hours after the administration of 75 g of glucose during OGTT. Troglitazone therapy (400 mg/day) was begun, and the BAVA evaluation was repeated after 2 and 4 months. These results were compared with the results of the control group who had normal fasting glucose levels, normal OGTT results, and no evidence of PVD. A paired t test was used to compare the BA flow before and after BA occlusion, with a P value of less than .05 considered significant. Results: The control group had a normal hyperemic response with a significantly increased BA flow after 5 minutes of BA occlusion during fasting and at all stages of the OGTT. The occult diabetic group had an abnormal response to hyperemia before the treatment with troglitazone and showed little change in flow after BA occlusion. After 2 months of troglitazone therapy, BAVA results improved after oral glucose intake but not during fasting. After 4 months, BAVA results normalized both while fasting and after oral glucose intake during the OGTT. Conclusion: Patients with occult diabetes and PVD have impaired BAVA, which normalizes after treatment with troglitazone. Insulin-action enhancers may slow the progression of PVD in patients with diabetes by improving endothelial cell function. Agents that are aimed at enhancing the action of insulin may have an advantage over the other traditional therapies for diabetes. (J Vasc Surg 1998;28:1024-32.)

Insulin resistance in patients with a recent diagnosis of coronary artery disease.

To elucidate whether insulin resistance is present in coronary artery disease (CAD) at diagnosis and to study its relationship with other known cardiovascular risk factors. We evaluated the incidence of insulin resistance in 40 newly diagnosed CAD patients. Fifteen healthy subjects were used as a control group. The patients and controls had no previous history of metabolic disorders, and were not being administered any medication that might have affected their insulin sensitivity. Immediately after diagnosis of CAD, a standard 75 g oral glucose-tolerance test (OGTT) and an insulin suppression test (IST) were performed on separate days. The IST consisted of a constant infusion of glucose, insulin and somatostatin for 150 min; insulin resistance was estimated by determining the steady-state plasma glucose (SSPG) concentrations during the last 60 min of the test. The insulin sensitivity index (ISI) was calculated by the formula ISI = (glucose infusion rate/SSPG]x10(3). Insulin resistance, defined by an ISI below the normal range derived from the control group, was present in 82.5% of the CAD patients. As a group, the patients with CAD displayed lower ISI (means +/- SD:29.23 +/- 11.23 versus 50.33 +/- 9.37 dl/kg per min, P < 0.001) than did controls. Serum triglycerides and uric acid were higher and high-density lipoprotein cholesterol levels were lower in patients than they were in controls. No differences were observed in fasting plasma insulin, glucose, total and low-density lipoprotein cholesterol concentration. An abnormal OGTT result was observed in 27 patients. The ISI was low in 88.8% of the patients with an abnormal OGTT result and in 69% of the 13 patients with a normal OGTT result. Insulin resistance and even impaired glucose tolerance are common findings in CAD at diagnosis. The changes in the lipid profile and in uric acid levels paralleled the changes in insulin sensitivity. These results suggest that insulin resistance might play a role in the development of coronary atherosclerosis and that its early diagnosis might be important in the prophylaxis of CAD.

Diagnosis and Management of Diabetes Mellitus: A Clinical Manual for Medical Students, Residents, and Primary Care Physicians

Dr O. Charles Olson has written a clear and concise manual on the care of the diabetic patient. Based on more than 30 years of clinical experience, he has compiled a soft-cover book of 35 chapters totaling 275 pages. It is written for medical students, house officers, primary care physicians, and, I would add, could be very useful to interested nurses, allied health professionals, and well-informed patients. The initial section clearly reviews the newer classification of diabetes. This is followed by an exceptionally helpful chapter on diagnosis, including criteria for diagnosis, preparation and timing of an oral glucose tolerance test (OGTT), when not to do an OGTT, and nondiabetic causes of abnormal OGTT results. Chapters 3 through 9 deal with the day-to-day management of the type I and II diabetic. Dietary management is covered in a cookbook fashion, and an interesting page on the use of dietary fiber is presented.