Hemoglobin A1c in predicting progression to diabetes.
ABSTRACT The predictive value of hemoglobin A1c (HbA1c) in comparison to fasting plasma glucose (FPG) is evaluated for 5-year incident diabetes (DM), as HbA1c may be more practical than FPG in the screening for DM in the future. Of 1189 non-DM subjects aged 35-89 years old from the Funagata Study, 57 subjects (4.8%) had developed DM on the WHO criteria at 5-year follow-up. The odds ratio (95% confidence interval: CI) for a one standard deviation increase in FPG/HbA1c was 3.40 (2.44-4.74)/3.49 (2.42-5.02). The area under the receiver operating characteristic curve for FPG/HbA1c was 0.786 (95% CI: 0.719-0.853)/0.785 (0.714-0.855). The HbA1c corresponding to FPG 5.56 mmol/l was HbA1c 5.3%. There was no statistical difference in sensitivity between FPG 5.56 mmol/l and HbA1c 5.3% (61.4% vs. 56.1%), while specificity was higher in HbA1c 5.3% than FPG 5.56 mmol/l (87.8% vs. 82.5%, p-value<0.001). The fraction of incident case from those with baseline IGT was similar between the groups, however the fraction of people above the cut-off was significantly lower in HbA1c 5.3% than FPG 5.56 mmol/l (14.3% vs. 19.6%, p-value<0.001). HbA1c is similar to FPG to evaluate DM risk, and HbA1c could be practical and efficient to select subjects for intervention.
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ABSTRACT: Our objective was to review modelling methods for type 2 diabetes mellitus prevention cost-effectiveness studies. The review was conducted to inform the design of a policy analysis model capable of assisting resource allocation decisions across a spectrum of prevention strategies. We identified recent systematic reviews of economic evaluations in diabetes prevention and management of obesity. We extracted studies from two existing systematic reviews of economic evaluations for the prevention of diabetes. We extracted studies evaluating interventions in a non-diabetic population with type 2 diabetes as a modelled outcome, from two systematic reviews of obesity intervention economic evaluations. Databases were searched for studies published between 2008 and 2013. For each study, we reviewed details of the model type, structure, and methods for predicting diabetes and cardiovascular disease. Our review identified 46 articles and found variation in modelling approaches for cost-effectiveness evaluations for the prevention of type 2 diabetes. Investigation of the variables used to estimate the risk of type 2 diabetes suggested that impaired glucose regulation, and body mass index were used as the primary risk factors for type 2 diabetes. A minority of cost-effectiveness models for diabetes prevention accounted for the multivariate impacts of interventions on risk factors for type 2 diabetes. Twenty-eight cost-effectiveness models included cardiovascular events in addition to type 2 diabetes. Few cost-effectiveness models have flexibility to evaluate different intervention types. We conclude that to compare a range of prevention interventions it is necessary to incorporate multiple risk factors for diabetes, diabetes-related complications and obesity-related co-morbidity outcomes.Applied Health Economics and Health Policy 03/2014;
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ABSTRACT: Background: To elucidate the impact of insufficient insulin secretion on subclinical glucose dysregulation in association with increased insulin resistance and aging. Methods: We conducted a cross-sectional study of 3950 Japanese subjects using homeostasis model assessment (HOMA)-derived indices. We compared β-cell function according to insulin resistance or age groups. Interaction between insulin resistance and aging on β-cell function was assessed using two-way analysis of variance (ANOVA). Results: Increased insulin resistance resulted in higher blood glucose levels and apparently higher insulin secretion, but compensatory insulin secretion was considered insufficient to suppress subclinical blood glucose elevation. Along with aging, fasting blood glucose became higher without changes in serum insulin levels and HOMA-derived indices for β-cell function significantly decreased. Two-way ANOVA revealed that insulin resistance and aging independently influenced β-cell function and the effects of insulin resistance on β-cell function were more dominant than those of aging. Conclusion: Our study shows that β-cell dysfunction is a major contributor in determining glucose disposal and insufficient insulin secretion is already present even when glucose levels rise into the “highnormal” range. Insulin secretion should be evaluated in relation to insulin resistance, as the observed insulin secretion may be insufficient to adjust plasma glucose concentrations.Ningen Dock. 03/2011; 25(6):37-44.