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Aims: To describe the roles of intra-abdominal fat and its change in the remission of impaired glucose tolerance (IGT) to normal glucose tolerance (NGT).Methods: We followed 157 Japanese Americans with IGT at baseline for 10-11 years without external intervention. We measured intra-abdominal and abdominal subcutaneous fat area (IAFA and ASFA) by computed tomography at baseline and at 5-6 years of follow-up. Change in IAFA and ASFA (ΔIAFA and ΔASFA) were calculated by subtracting baseline fat area from 5-6 year follow-up fat area. Glucose and insulin at fasting and during a 75-g oral glucose tolerance test, insulinogenic index (IGI [Δinsulin/Δglucose (30-0 min)]) and homeostasis model assessment for insulin resistance (HOMA-IR) were measured at baseline.Results: Fourty-four subjects remitted to NGT. Among those with lower IAFA (≤median 91.31 cm2) and the lowest tertile of ΔIAFA, 45% remitted, while with higher IAFA (>91.31 cm2) and the highest tertile of ΔIAFA, only 12.5% remitted. ΔIAFA was significantly associated with remission to NGT (multiple-adjusted odd ratio [1-SD decrease] 1.93, 95% CI 1.10-3.36) independent of IAFA, ASFA, ΔASFA, IGI, HOMA-IR, age, sex, and family history of diabetes.Conclusions: In the natural history of IGT, change in intra-abdominal fat was associated with remission to NGT. [ABSTRACT FROM AUTHOR]

Objective: Recent studies have suggested that HDL cholesterol is inversely associated with the development of type 2 diabetes. However, little is known about the association between different HDL subclasses and the risk for future type 2 diabetes.Research Design and Methods: The study enrolled 406 Japanese Americans (51% male) without diabetes, aged 34-75 years. Oral glucose tolerance tests were performed to determine type 2 diabetes status at baseline, 2.5 years, 5 years, and 10 years after enrollment. HDL2, HDL3, total HDL cholesterol, and visceral adipose tissue (VAT) area by computed tomography were measured at baseline.Results: In univariate analysis, total HDL and HDL2 cholesterol were inversely associated with the incidence of type 2 diabetes, but HDL3 cholesterol was not. In multivariate analysis, total HDL cholesterol (odds ratio per 1-SD increment, 0.72 [95% CI 0.52-0.995], P = 0.047) and HDL2 cholesterol (odds ratio per 1-SD increment, 0.64 [95% CI 0.44-0.93], P = 0.018) were inversely associated with the risk for type 2 diabetes independent of age, sex, BMI, waist circumference, family history of diabetes, lifestyle factors, systolic blood pressure, lipid-lowering medication use, triglyceride level, HOMA-insulin resistance, and 2-h glucose; however, HDL3 cholesterol was not associated with diabetes risk. The association between diabetes risk and total HDL and HDL2 cholesterol became insignificant after adjustment for VAT area.Conclusions: Subjects with higher HDL2 cholesterol were at lower risk for incident type 2 diabetes, but this association was confounded by and not independent of VAT. Higher HDL3 cholesterol was not associated with diabetes risk. [ABSTRACT FROM AUTHOR]

Objective: Greater visceral adiposity, higher insulin resistance, and impaired insulin secretion increase the risk of type 2 diabetes. Whether visceral adiposity increases risk of impaired glucose tolerance (IGT) independent of other adipose depots, insulin resistance, and insulin secretion is not known.Research Design and Methods: Study subjects included 128 Japanese Americans with normal glucose tolerance at entry. Baseline variables included plasma glucose and insulin measured after an overnight fast and during a 75-g oral glucose tolerance test, fat areas by computed tomography, insulin secretion (incremental insulin response [IIR] [30 min insulin - fasting insulin]/30 min glucose), and insulin resistance index (homeostasis model assessment for insulin resistance [HOMA-IR]).Results: During the 10- to 11-year follow-up period, we confirmed 57 cases of IGT. Significant predictors of IGT included intra-abdominal fat area (IAFA) (odds ratio [OR] for a 1 SD increase 3.82, 95% CI 1.63-8.94 at a fasting plasma glucose [FPG] level of 4.5 mmol/l), HOMA-IR (2.41, 1.15-5.04), IIR (0.30, 0.13-0.69 at an FPG level of 4.5 mmol/l), the interactions of IAFA by FPG (P = 0.003), and IIR by FPG (P = 0.030) after adjusting for age, sex, FPG, and BMI. The multiple-adjusted OR of IAFA increased and that of IIR decreased as FPG level decreased because of these interactions. Even after adjustment for total fat area, total subcutaneous fat area, or abdominal subcutaneous fat area, all of these associations remained a significant predictor of IGT incidence.Conclusions: Greater visceral adiposity increases the risk of IGT independent of insulin resistance, insulin secretion, and other adipose depots in Japanese Americans. [ABSTRACT FROM AUTHOR]

Presents information on a study regarding the effect of impaired fasting glucose (IFG) in increasing the risk of hypertension on Japanese cohorts during 1980 and 1990. Diagnosis of diabetes, IFG and hypertension; Biochemical measurements and clinical characteristics of the study; Result and discussion.

Aims: We compared 20 previously reported indices of insulin sensitivity derived from samples during an oral glucose tolerance test (OGTT) to determine which was best in predicting incident type 2 diabetes.Methods: We prospectively followed 418 Japanese Americans without diabetes for 10-11 years. We compared ability to predict incident diabetes of 20 insulin sensitivity indices-9 based on fasting samples, 7 based on 2-h and/or fasting samples, and 4 based on multiple samples (0, 30, 60, 120 min) during an OGTT-by integrated discrimination improvement, category free net reclassification improvement, and area under the receiver operator characteristic curve.Results: There were 95 incident cases of diabetes. The Cederholm and Gutt indices, requiring more than only fasting samples, were the best to predict incident diabetes as judged by integrated discrimination improvement (0.187, 0.184), category free net reclassification improvement (0.962, 1.030), and area under the receiver operator characteristic curve (0.864, 0.863, respectively). Fasting indices were clearly inferior to both the Cederholm and Gutt indices.Conclusions: Among the 20 indices, the Cederholm and Gutt indices predicted diabetes best but the Gutt index may be preferable because it requires fewer samples during an OGTT. [ABSTRACT FROM AUTHOR]