All Pre-Diabetes Is Not the Same: Metabolic and Vascular Risks of Impaired Fasting Glucose at 100 Versus 110 mg/dl

Abstract

T he dramatic increase in incidence of diabetes (1) has prompted efforts to identify individuals who have milder glucose intolerance, because early management with lifestyle change and/or medication can delay progression to diabetes with its attendant morbidity, mortality, and cost (2). It has long been recognized that impaired glucose tolerance (IGT) is a diabetes precursor, but recognition of IGT requires oral glucose tolerance tests (OGTTs), which many health care providers are reluctant to order (3). As a more convenient alternative, the American Diabetes Association has emphasized screening by measurement of fasting plasma glucose (FPG) and lowered the cutoff for abnormal FPG progressively from 140 to 125 to 110 mg/dl. However, compared with IGT, an impaired fasting glucose (IFG) cutoff of 110 mg/dl provided good specificity but reduced sensitivity for detecting risk of developing diabetes (4 -6).To obtain increased sensitivity, the American Diabetes Association recently lowered the cutoff for IFG from 110 to 100 mg/dl (7), and application of this cutoff has increased the number of Americans thought to have "pre-diabetes" to 41 million (8). Although such individuals are considered candidates for management aimed at decreasing their risk of progressing to diabetes (9), the metabolic and cardiovascular risks of individuals with very modest abnormalities in FPG are not well understood. In this study, we compared measures of risk in individuals with fasting glucose 100 -109 mg/dl (IFG100) with those with fasting glucose 110 -125 mg/dl (IFG110). RESEARCH DESIGN AND METHODS -The study was approved by the Emory University Institutional Review Board and involved 550 adult volunteer subjects who were not known to have diabetes and were in general good health (had not needed to miss work during the previous week). As part of the Screening for Impaired Glucose Tolerance (SIGT) study, standard 75-g OGTTs were performed in the morning after an overnight fast, and fasting blood and urine samples were obtained for measurement of biomarkers. Normal glucose tolerance (NGT) was characterized by fasting glucose Ͻ100 mg/dl and 2-h glucose Ͻ140 mg/dl, IGT by 2-h glucose 140 -199 mg/dl, diabetes by 2-h glucose Ն200 mg/dl, and IFG as described above; 13 subjects with fasting glucose Ͼ125 mg/dl were excluded from analysis because they could not be included in the IFG categories. Plasma glucose and other biomarkers were measured in the Clinical Laboratory at Grady Memorial Hospital using the Beckman LX-20 (Beckman, Brea, CA). Biomarkers were expressed relative to the upper quintile (high) of values of the 368 subjects with NGT. The "metabolic syndrome" was examined as defined by both International Diabetes Federation (10) and National Cholesterol Education Program (NCEP) (11) criteria. Statistical analyses were conducted using S-Plus, version 6 (Insightful, Seattle, WA), and Stata, version 7 (Stata, College Station, TX). RESULTS -Clinical demographicswere similar in 95 subjects with IFG100 compared with 41 subjects with IFG110, res...

Comprehensive Identification of Glycated Peptides and Their Glycation Motifs in Plasma and Erythrocytes of Control and Diabetic Subjects

“…Human blood plasma and erythrocyte samples were received frozen on dry ice from the Screening for Impaired Glucose Tolerance (SIGT) study 28 via the National Institute for Diabetes and Digestive and Kidney Diseases Central Repository. Samples were divided into three groups by the SIGT based on the results of the OGTT: normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM).…”

Metabolic risk factors in southern Taiwanese with impaired fasting glucose of 100 to 109 mg/dL

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