Antecubital Vein Cannula Position Impacts Assessment of Forearm Glucose Uptake During an Oral Glucose Challenge in Healthy Volunteers.

INTRODUCTION: Skeletal muscle is a major site for whole-body glucose disposal, and determination of skeletal muscle glucose uptake is an important metabolic measurement, particularly in research focussed on interventions that impact muscle insulin sensitivity. Calculating arterial-venous difference in blood glucose can be used as an indirect measure for assessing glucose uptake. However, the possibility of multiple tissues contributing to the composition of venous blood, and the differential in glucose uptake kinetics between tissue types, suggests that sampling from different vein sites could influence the estimation of glucose uptake. This study aimed to determine the impact of venous cannula position on calculated forearm glucose uptake following an oral glucose challenge in resting and post-exercise states. MATERIALS AND METHODS: In 9 young, lean, males, the impact of sampling blood from two antecubital vein positions; the perforating vein ('perforating' visit) and, at the bifurcation of superficial and perforating veins ('bifurcation' visit), was assessed. Brachial artery blood flow and arterialised-venous and venous blood glucose concentrations were measured in 3 physiological states; resting-fasted, resting-fed, and fed following intermittent forearm muscle contraction (fed-exercise). RESULTS: Following glucose ingestion, forearm glucose uptake area under the curve was greater for the 'perforating' than for the 'bifurcation' visit in the resting-fed (5.92±1.56 vs. 3.69±1.35 mmol/60 min, P<0.01) and fed-exercise (17.38±7.73 vs. 11.40±7.31 mmol/75 min, P<0.05) states. DISCUSSION: Antecubital vein cannula position impacts calculated postprandial forearm glucose uptake. These findings have implications for longitudinal intervention studies where serial determination of forearm glucose uptake is required.

Clinical and Public Health Implications of 2019 Endocrine Society Guidelines for Diagnosis of Diabetes in Older Adults.

OBJECTIVE: Screening for diabetes is typically done using hemoglobin A1c (HbA1c) or fasting plasma glucose (FPG). The 2019 Endocrine Society guidelines recommend further testing using an oral glucose tolerance test (OGTT) in older adults with prediabetic HbA1c or FPG. We evaluated the impact of this recommendation on diabetes prevalence, eligibility for glucose-lowering treatment, and estimated cost of implementation in a nationally representative sample. RESEARCH DESIGN AND METHODS: We included 2,236 adults aged ≥65 years without known diabetes from the 2005-2016 National Health and Nutrition Examination Survey. Diabetes was defined using: 1) the Endocrine Society approach (HbA1c ≥6.5%, FPG ≥126 mg/dL, or 2-h plasma glucose ≥200 mg/dL among those with HbA1c 5.7-6.4% or FPG 100-125 mg/dL); and 2) a standard approach (HbA1c ≥6.5% or FPG ≥126 mg/dL). Treatment eligibility was defined using HbA1c cut points (≥7% to ≥9%). OGTT screening costs were estimated using Medicare fee schedules. RESULTS: Diabetes prevalence was 15.7% (∼5.0 million) using the Endocrine Society's approach and 7.3% (∼2.3 million) using the standard approach. Treatment eligibility ranged from 5.4% to 0.06% and 11.8% to 1.3% for diabetes cases identified through the Endocrine Society or standard approach, respectively. By definition, diabetes identified exclusively through the Endocrine Society approach had HbA11c <6.5% and would not be recommended for glucose-lowering treatment. Screening all older adults with prediabetic HbA1c/FPG (∼18.3 million) with OGTT could cost between $737 million and $1.7 billion. CONCLUSIONS: Adopting the 2019 Endocrine Society guidelines would substantially increase the number of older adults classified as having diabetes, require significant financial resources, but likely offer limited benefits.

Difference in the prevalence of gestational diabetes mellitus according to gestational age at 75-g oral glucose tolerance test in Japan: The Japan Assessment of Gestational Diabetes Mellitus Screening trial.

AIMS/INTRODUCTION: To evaluate the differences in the results of 75-g oral glucose tolerance tests (OGTTs) according to gestational age in Japan. MATERIALS AND METHODS: In this prospective cohort study, 2,578 pregnant women were divided into three categories based on their gestational age during the 75-g OGTT: <14 weeks' gestation, 14-23 weeks' gestation and 24-32 weeks' gestation. The association between gestational age and the results of the 75-g OGTT were evaluated using multivariable analysis. RESULTS: Early gestational age was associated with high fasting plasma glucose levels at the time of the 75-g OGTT, and low corresponding 1-h and 2-h plasma glucose levels. Compared with women with a gestational age of 24-32 weeks, women who had undergone the 75-g OGTT at <14 weeks' gestation had significantly higher odds of gestational diabetes mellitus diagnosis based on the currently used criteria in Japan (adjusted odds ratio 1.42, 95% confidence interval 1.07-1.90). CONCLUSIONS: The results of the 75-g OGTT varied by gestational age. The use of the same 75-g OGTT cut-off values for the diagnosis of gestational diabetes mellitus, regardless of gestational age, might lead to increases in the prevalence of gestational diabetes mellitus diagnosis in Japan.

Assessing the predictive accuracy of oral glucose effectiveness index using a calibration model.

PURPOSE: Current reference methods for measuring glucose effectiveness (GE) are the somatostatin pancreatic glucose clamp and minimal model analysis of frequently sampled intravenous glucose tolerance test (FSIVGTT), both of which are laborious and not feasible in large epidemiological studies. Consequently, surrogate indices derived from an oral glucose tolerance test (OGTT) to measure GE (oGE) have been proposed and used in many studies. However, the predictive accuracy of these surrogates has not been formally validated. In this study, we used a calibration model analysis to evaluate the accuracy of surrogate indices to predict GE from the reference FSIVGTT (SgMM). METHODS: Subjects (n = 123, mean age 48 ± 11 years; BMI 35.9 ± 7.3 kg/m2) with varying glucose tolerance (NGT, n = 37; IFG/IGT, n = 78; and T2DM, n = 8) underwent FSIVGTT and OGTT on two separate days. Predictive accuracy was assessed by both root mean squared error (RMSE) of prediction and leave-one-out cross-validation-type RMSE of prediction (CVPE). RESULTS: As expected, insulin sensitivity, SgMM, and oGE were reduced in subjects with T2DM and IFG/IGT when compared with NGT. Simple linear regression analyses revealed a modest but significant relationship between oGE and SgMM (r = 0.25, p < 0.001). However, using calibration model, measured SgMM and predicted SgMM derived from oGE were modestly correlated (r = 0.21, p < 0.05) with the best fit line suggesting poor predictive accuracy. There were no significant differences in CVPE and RMSE among the surrogates, suggesting similar predictive ability. CONCLUSIONS: Although OGTT-derived surrogate indices of GE are convenient and feasible, they have limited ability to robustly predict GE.

Generalized sensitivity analysis of the minimal model of the intravenous glucose tolerance test.

Generalized sensitivity functions characterize the sensitivity of the parameter estimates with respect to the nominal parameters. We observe from the generalized sensitivity analysis of the minimal model of the intravenous glucose tolerance test that the measurements of insulin, 62 min after the administration of the glucose bolus into the experimental subject's body, possess no information about the parameter estimates. The glucose measurements possess the information about the parameter estimates up to three hours. These observations have been verified by the parameter estimation of the minimal model. The standard errors of the estimates and crude Monte Carlo process also confirm this observation.

A new predictive tool for the early risk assessment of gestational diabetes mellitus.

AIMS: The Italian National Institute of Health has recently introduced a selective screening based on the risk profile of pregnant women, which while recommending against screening of women at low risk (LR) for GDM, it recommends an early test for women at high risk (HR) for GDM. Herein, we assessed the accuracy and cost-effectiveness of this screening and developed a new index that improves these requirements. METHODS: We retrospectively enrolled 3974 pregnant women. GDM was diagnosed with a 2h 75-g OGTT at 16-18 weeks (early test) or 24-28 weeks of gestation, according to the IADPSG guidelines. RESULTS: 55.6% of HR women had GDM, although only 38.4% underwent early screening. Among 2654 women at medium risk, 20.9% had GDM; paradoxically, among 770 LR women, that would not have been screened, 26.6% received a GDM diagnosis. Based on these unsatisfactory results, we elaborated the Capula's index, that reduced both screening tests (p<0.001) and potentially undetected GDM cases (p<0.001), and corrected the paradoxical prevalence estimates of GDM obtained with the current Italian guidelines. Also, Capula's index improved correlation of GDM risk profile with obstetric and neonatal adverse events. CONCLUSIONS: Capula's index improves accuracy of selective screening for GDM.

Screening for type 2 diabetes: a short report for the National Screening Committee.

BACKGROUND: The prevalence of type 2 diabetes mellitus (T2DM) has been increasing, owing to increases in overweight and obesity, decreasing physical activity and the changing demographic structure of the population. People can develop T2DM without symptoms and up to 20% may be undiagnosed. They may have diabetic complications, such as retinopathy, by the time they are diagnosed, or may suffer a heart attack, without warning. Undiagnosed diabetes can be detected by raised blood glucose levels. AIM: The aim of this review was to provide an update for the UK National Screening Committee (NSC) on screening for T2DM. METHODS: As this review was undertaken to update a previous Health Technology Assessment review published in 2007, and a more recent Scottish Public Health Network review, searches for evidence were restricted from 2009 to end of January 2012, with selected later studies added. The databases searched were MEDLINE, EMBASE, MEDLINE-in-Process & Other Non-Indexed Citations, Science Citation Index and Conference Proceedings Citation Index. The case for screening was considered against the criteria used by the NSC to assess proposed population screening programmes. RESULTS: Population screening for T2DM does not meet all of the NSC criteria. Criterion 12, on optimisation of existing management, has not been met. A report by the National Audit Office (NAO) gives details of shortcomings. Criterion 13 requires evidence from high-quality randomised controlled trials that screening is beneficial. This has not been met. The Ely trial of screening showed no benefit. The ADDITION trial was not a trial of screening, but showed no benefit in cardiovascular outcomes from intensive management in people with screen-detected T2DM. Criterion 18 on staffing and facilities does not appear to have been met, according to the NAO report. Criterion 19 requires that all other options, including prevention, should have been considered. A large proportion of cases of T2DM could be prevented if people avoided becoming overweight or obese. The first stage of selection would use risk factors, using data held on general practitioner computer systems, using the QDiabetes Risk Score, or by sending out questionnaires, using the Finnish Diabetes Risk Score (FINDRISC). Those at high risk would have a measure of blood glucose. There is no perfect screening test. Glycated haemoglobin (HbA1c) testing has advantages in not requiring a fasting sample, and because it is a predictor of vascular disease across a wider range than just the diabetic one. However, it lacks sensitivity and would miss some people with diabetes. Absolute values of HbA1c may be more useful as part of overall risk assessment than a dichotomous 'diabetes or not diabetes' diagnosis. The oral glucose tolerance test is more sensitive, but inconvenient, more costly, has imperfect reproducibility and is less popular, meaning that uptake would be lower. CONCLUSIONS: When considered against the NSC criteria, the case for screening is less strong than it was in the 2007 review. The main reason is the absence of cardiovascular benefit in the two trials published since the previous review. There is a case for selective screening as part of overall vascular risk assessment. Population screening for T2DM does not meet all of the NSC criteria. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

HbA1c for screening and diagnosis of diabetes mellitus.

HbA1c has become the gold standard for monitoring glycemic control in patients with diabetes mellitus. The use of this test has been expanded to diagnose and screen for diabetes mellitus with the endorsement of influential diabetes societies and the World Health Organization. The literature on the use of HbA1c for the diagnosis and screening of diabetes mellitus was critically examined. There is substantial recent literature on this topic with strong advocates for the use of HbA1c to diagnose and screen for diabetes and equally strong detractors for its use. Advocates of the use of HbA1c cite challenges in respect of patient compliance and the analysis of glucose and inconsistency of diagnosis with glucose-based diabetes diagnosis with the elimination or reduction in these challenges in HbA1c-based diagnosis. Detractors of its use cite increased cost, concerns about the availability of HbA1c testing, and the influence of demographic and clinical factors on HbA1c results that make the use of a single-threshold values questionable for different ethnic and age groups. Despite the recommendation of many international diabetes societies that HbA1c be used for screening and diagnosis of diabetes mellitus, there is a wide divergence of opinion on this use.

Combined assessment of glycated albumin and fasting plasma glucose improves the detection of diabetes in Chinese subjects.

1. The aim of the present study was to assess the validity of glycated albumin (GA) and fasting plasma glucose (FPG) as a screening tool for the early detection of diabetes in Chinese subjects. 2. A total of 1971 outpatient subjects underwent a 75 g oral glucose tolerance test (OGTT) and GA measurement. The receiver operating characteristic curve (ROC) was plotted to examine the sensitivity, specificity, and positive and negative predictive values of GA and FPG in detecting undiagnosed diabetes at the different cut-off levels. 3. The prevalence of impaired glucose regulation and diabetes was 27.40% and 38.30%. For these diabetic individuals, 4.64% had isolated fasting hyperglycemia, 50.86% had isolated postprandial hyperglycemia and 44.50% had both. Using ROC analysis, a GA of 17.1% gave an optimal sensitivity of 76.82% (95% confidence interval: 73.64-79.79%) and specificity of 76.89% (74.42-79.23%) for the diagnosis of diabetes. Likewise, a FPG of 6.1 mmol/L gave an optimal sensitivity of 80.93% (77.94-83.67%) and specificity of 85.94% (83.86-87.84%). If subjects met both criteria, they were regarded as having diabetes; the positive predictive value of the combined criteria, FPG ≥ 6.1 mmol/L and GA ≥ 17.1%, was relatively high (84.79% (81.62-87.60%)), and this would have avoided 76% of the OGTT in our survey. 4. In conclusion, a GA value of 17.1%, an optimal cut-off in Chinese subjects, identified a high proportion of potential diabetic individuals. Simultaneous measurement of FPG and GA would enhance the sensitivity of diabetes screening in our population and avoid 76% of OGTT.

Screening for gestational diabetes mellitus: U.S. Preventive Services Task Force recommendation statement.

DESCRIPTION: Update of 2003 U.S. Preventive Services Task Force (USPSTF) recommendation about screening for gestational diabetes. METHODS: The USPSTF weighed the evidence on maternal and neonatal benefits (reduction in preeclampsia, mortality, brachial plexus injury, clavicular fractures, admission to the neonatal intensive care unit for serious illnesses) and harms (physical and psychological harms) of screening for gestational diabetes identified for their 2003 recommendation and the accompanying systematic review of articles published since the 2003 review for screening after 24 weeks' gestation. Additional searches were performed for evidence published from 1966 to 1999 on screening before 24 weeks. RECOMMENDATION: Current evidence is insufficient to assess the balance of benefits and harms of screening for gestational diabetes mellitus, either before or after 24 weeks' gestation. (I statement.).

Screening for gestational diabetes mellitus: a systematic review for the U.S. Preventive Services Task Force.

BACKGROUND: In 2003, the U.S. Preventive Services Task Force concluded that evidence was insufficient to advise for or against routinely screening all pregnant women for gestational diabetes mellitus. PURPOSE: To review evidence about the benefits and harms of screening for gestational diabetes. DATA SOURCES: Databases (MEDLINE, Database of Abstracts of Reviews of Effects, Health Technology Assessment Database, National Institute for Health and Clinical Effectiveness, and Cochrane Library) were searched for reports published from January 2000 to 15 November 2007 (and from 1966 to 1999 for additional studies on screening at less than 24 weeks' gestation), citations in the 2003 evidence report, and studies identified through consultation of experts and searches of bibliographies. STUDY SELECTION: English-language studies that used standard 1- or 2-step testing for gestational diabetes and that evaluated at least 1 of the following outcomes: neonatal mortality; brachial plexus injury; clavicular fracture; admission to a neonatal intensive care unit for hypoglycemia, hyperbilirubinemia, or the respiratory distress syndrome; maternal mortality; and preeclampsia or pregnancy-induced hypertension. DATA EXTRACTION: 2 reviewers evaluated 1607 abstracts, critically appraised 288 articles, and qualitatively synthesized 13 studies. DATA SYNTHESIS: No randomized, controlled trials that directly evaluated the risks and benefits of gestational diabetes screening were found. One good-quality randomized, controlled trial of treatment of mild gestational diabetes in a screening-detected population supported a reduction in serious neonatal complications and showed that gestational diabetes treatment also reduced the risk for gestational hypertension. Very limited evidence was found to evaluate early screening for gestational diabetes (before 24 weeks' gestation). Limited evidence suggests that serious maternal hypoglycemia is rare with treatment and that overall quality of life is not worse among women receiving gestational diabetes treatment compared with women not receiving treatment. LIMITATION: The literature is limited by lack of a consistent standard for screening or diagnosis of gestational diabetes. CONCLUSION: Limited evidence suggests that gestational diabetes treatment after 24 weeks improves some maternal and neonatal outcomes. Evidence is even more sparse for screening before 24 weeks' gestation.

[Critical analysis on the use of the homeostasis model assessment (HOMA) indexes in the evaluation of the insulin resistance and the pancreatic beta cells functional capacity]. / Análise crítica do uso dos índices do Homeostasis Model Assessment (HOMA) na avaliação da resistência à insulina e capacidade funcional das células-beta pancreáticas.

Beta-cell dysfunction and insulin resistance are interrelated metabolic abnormalities in the aetiology of Type 2 Diabetes. In several countries, increases in the prevalence of obesity and diabetes have been observed in association with the presence of insulin resistance. In this context, measurement of insulin resistance and beta-cell function is useful. The HOMA indexes (Homeostasis Model Assessment) have been widely used, representing an alternative for the evaluation of these parameters, particularly as a fast, easy and cheap method. This review discusses the origin and evolution of the HOMA index, as well as details of the method, analyzing features related to its validation and the cutoff limits for its interpretation.

Análise crítica do uso dos índices do Homeostasis Model Assessment (HOMA) na avaliação da resistência à insulina e capacidade funcional das células-beta pancreáticas: [revisão] / Critical analysis on the use of the homeostasis hodel assessment (HOMA) indexes in the evaluation of the insulin resistance and the pancreatic beta cells functional capacity: [review]

A disfunção das células-beta e a resistência insulínica são anormalidades metabólicas inter-relacionadas na etiologia do diabetes tipo 2. Em diversos países, tem sido observado o aumento da prevalência de obesidade e diabetes em associação com a presença da resistência insulínica. Nesse contexto, é útil a mensuração da resistência insulínica e da capacidade funcional das células-beta nos indivíduos. Os índices Homeostasis Model Assessment (HOMA) têm sido amplamente utilizados, representando uma das alternativas para avaliação desses parâmetros, principalmente por figurarem um método rápido, de fácil aplicação e de menor custo. Esta revisão discute sobre a origem e a evolução dos índices HOMA, bem como as particularidades do método, abordando aspectos relacionados à sua validação e aos pontos de corte existentes para sua interpretação.

Beta-cell dysfunction and insulin resistance are interrelated metabolic abnormalities in the aetiology of Type 2 Diabetes. In several countries, increases in the prevalence of obesity and diabetes have been observed in association with the presence of insulin resistance. In this context, measurement of insulin resistance and beta-cell function is useful. The HOMA indexes (Homeostasis Model Assessment) have been widely used, representing an alternative for the evaluation of these parameters, particularly as a fast, easy and cheap method. This review discusses the origin and evolution of the HOMA index, as well as details of the method, analyzing features related to its validation and the cutoff limits for its interpretation.

Measuring insulin sensitivity in postmenopausal women covering a range of glucose tolerance: comparison of indices derived from the oral glucose tolerance test with the euglycemic-hyperinsulinemic clamp.

This study compares indices of insulin sensitivity derived from fasting and oral glucose tolerance test (OGTT) glucose and insulin measurements, with respect to the reference measure (M/I), obtained from the euglycemic-hyperinsulinemic clamp, in postmenopausal women with varying glucose tolerance status. Fasting plasma insulin index, homeostasis model assessment index, and OGTT-derived indices (insulin 120-minute, Matsuda, metabolic clearance rate [MCR] of glucose, insulin sensitivity [ISI], and Cederholm indices) were calculated and compared with the M/I value in 112 postmenopausal women. All indices examined were significantly correlated with M/I (0.28 < or = r(2) < or = 0.56). Association studies revealed that on average, 48% of women were grouped in the same tertile of insulin sensitivity when using M/I and fasting plasma insulin index, and 54% when using M/I and insulin 120-minute index. However, concordance with M/I tertiles were 57%, 58%, 64%, 64%, and 68% for homeostasis model assessment, Matsuda, MCR, ISI, and Cederholm indices, respectively. Finally, correlation coefficients between M/I and insulin sensitivity indices were generally lower in women with normal glucose tolerance compared with women with impaired glucose tolerance or type 2 diabetes mellitus. These results suggest that in postmenopausal women, surrogate indices of insulin sensitivity obtained from OGTT data and incorporating a measurement of body weight or body mass index) (Cederholm, ISI, and MCR indices) appear to be superior to those without OGTT data or body weight-body mass index measurements and, therefore, could offer a better estimate of insulin sensitivity, allowing an improved clinical evaluation of this population at higher risk of cardiovascular disease and type 2 diabetes mellitus.

Comparison between 100-g glucose tolerance test and two other screening tests for gestational diabetes: combined fasting glucose with risk factors and 50-g glucose tolerance test.

CONTEXT AND OBJECTIVE: Lack of consensus about which screening tests to use for gestational diabetes mellitus (GDM) and difficulties in performing the gold-standard diagnostic test, the 100-g glucose tolerance test (100-g GTT), justify comparison with alternatives. The aim was to compare this with two other screening tests: combined fasting glucose with risk factors (FG + RF) and 50-g GTT. DESIGN AND SETTING: Prospective longitudinal cohort study in the Hospital School of Universidade Federal de Mato Grosso do Sul. METHODS: The three tests were performed independently on 341 pregnant women. Sensitivity (S), specificity (Sp), positive (PPV) and negative (NPV) predictive values, positive (PLR) and negative (NLR) likelihood ratios, and false-positive (FP) and false-negative (FR) rates obtained with FG + RF and 50-g GTT were compared with values from 100-g GTT. The average one-hour post-intake glucose levels (1hPG) with 50-g and 100-g were compared. Students t test was used in the statistical analysis. RESULTS: FG + RF led more pregnant women (53.9%) to diagnostic confirmation than did 50-g GTT (14.4%). The tests were equivalent for S (86.4 and 76.9%), PPV (98.7 and 98.9%), NLR (0.3 and 0.27) and FR (15.4 and 23.1%). Average 1hPG values were similar: 50-g GTT = 106.8 mg/dl and 100-g GTT = 107.5 mg/dl. CONCLUSION: Diagnostic efficiency with simplicity, practicality and low cost make FG + RF more appropriate for screening for GDM. The equivalence of 1hPG allows a new, cheaper and less uncomfortable protocol to be proposed for screening and diagnosing GDM.

Comparison between 100-g glucose tolerance test and two other screening tests for gestational diabetes: combined fasting glucose with risk factors and 50-g glucose tolerance test

CONTEXTO E OBJETIVO: A falta de consenso sobre os protocolos de rastreamento e diagnóstico do diabetes gestacional, associada às dificuldades na realização do teste oral simplificado do diabete gestacional (o teste de tolerância a 100 g de glicose, considerado padrão-ouro) justificam a comparação com alternativas. O objetivo deste trabalho é comparar o teste padrão-ouro a dois testes de rastreamento: associação de glicemia de jejum e fatores de risco (GJ + FR) e o teste oral simplificado de tolerância a 50 g de glicose (TTG 50 g), com o teste de tolerância a 100 g de glicose (TTG 100 g).TIPO DE ESTUDO E LOCAL: Estudo de coorte longitudinal, prospectivo, realizado no Serviço de Ginecologia e Obstetrícia do Hospital Universitário da Universidade Federal de Mato Grosso do Sul. MÉTODOS: 341 gestantes foram submetidas aos três testes. Calcularam-se os índices de sensibilidade (S), especificidade (E), valores preditivos (VPP e VPN), razões de probabilidade (RPP e RPN) e resultados falsos (FP e FN), positivos e negativos da associação GJ + FR e do TTG 50 g em relação ao TTG 100 g. Compararam-se as médias das glicemias de uma hora pós-sobrecarga (1hPS) com 50 e 100 g. Na análise estatística, empregou-se o teste t de Student, com limite de significância de 5%. RESULTADOS: A associação GJ + FR encaminhou mais gestantes (53,9%) para a confirmação diagnóstica que o TTG 50 g (14,4%). Os dois testes foram equivalentes nos índices de S (86,4 e 76,9%), VPN (98,7 e 98,9%), RPN (0,3 e 0,27) e FN (15,4 e 23,1%). As médias das glicemias 1hPS foram semelhantes, 106,8 mg/dl para o TTG 50 g e 107,5 mg/dl para o TTG 100 g. CONCLUSÕES: Os resultados da eficiência diagnóstica associados à simplicidade, praticabilidade e custo referendaram a associação GJ + FR como o mais adequado para o rastreamento. A equivalência das glicemias de 1hPS permitiram a proposição de um novo protocolo de rastreamento e diagnóstico do diabete gestacional, com menores custo e desconforto.

Population and individual minimal modeling of the frequently sampled insulin-modified intravenous glucose tolerance test.

Population approaches are more robust estimators of insulin sensitivity (SI) and glucose effectiveness (SG) with the minimal model of glucose kinetics during an intravenous glucose tolerance test (IVGTT). We assessed the performance of 3 population methods, iterative two-stage (ITS), Bayesian hierarchical Markov chain Monte Carlo (MCMC), and NONMEM first-order conditional estimation (FOCE) with interaction (NM), and made a comparison with the standard two-stage method (STS) employing the weighted nonlinear regression analysis. To evaluate accuracy of individual and population estimates, 40 simulated insulin-modified frequently sampled IVGTTs (IM-FSIVGTT) were derived from real IM-FSIVGTTs (0.3 g glucose per kg body weight with 0.02 U/kg insulin at 20 minutes; 30 samples over 180 minutes) performed in 40 healthy Caucasian subjects (male/female, 22/18; age, 46 +/- 9 years; body mass index [BMI], 26.7 +/- 5.7 kg. m(-2); mean +/- SD). The population methods assumed a log-normal population distribution of parameters. All methods gave a similar but overestimated population SG by 9% to 13%. Population SI was underestimated to a different degree by the methods (STS 6%, ITS 10%, MCMC 13%, and NM 7%). The between-subject variability of SG was overestimated by STS and underestimated by the population methods (true 33%, STS 40%, ITS 19%, MCMC 24%, NM 24%; coefficient of variation). For SI, this quantity was well estimated by all methods (true 79%, STS 80%, ITS 82%, MCMC 83%, NM 82%). The results for individual estimates indicate that STS performs better than the population methods when estimating SI (STS 12%, ITS 16%, MCMC 16%, NM 16%; 1 outlying subject excluded; root mean squared error expressed as percent of mean) but worse for SG (STS 28%, ITS 21%, MCMC 20%, NM 19%). We conclude that the robust performance of population approaches, preventing parameter estimation failures associated with the nonlinear regression analysis, is not required with IM-FSIVGTT in subjects with normal glucose tolerance. The standard two-stage technique is the preferred method under such circumstances.