Search

Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) are pre-diabetes states that can progress to type 2 diabetes mellitus. However, it has been shown that only 29 - 76% of pre-diabetic subjects diagnosed satisfy the definition of IFG and IGT simultaneously, and it appears that a significant difference between them is also present. We performed an oral glucose tolerance test (OGTT) on 528 subjects who had no history of the medication that affect on glucose tolerance, and the patients were classified into four groups: the normal glucose tolerance, the isolated IFG, the isolated IGT, and the combined glucose intolerance (CGI) group satisfying IFG and IGT conditions simultaneously. The characteristics of each group were compared. In addition, for all subjects, the insulin resistance indices HOMA-IR, WBISI, and the insulin secretion indices insulinogenic index (IGI), and AUC insulin[sub 0-120]/AUC glucose[sub 0-120] (AUC I/G 120) were determined. The OGTT measurements showed that 87 subjects were diagnosed as having isolated IFG, 75 subjects as having isolated IGT, and 145 subjects as having CGI, and 43.2% of the pre-diabetes subjects were placed in the CGI group. Comparing the isolated IFG and the isolated IGT group, the isolated IFG group was relatively young (49.9±11.3 years vs. 51.4±14.4 years, p=0.038), the percentage of male was higher (56.3% vs. 40%, p=0.028), and the isolated IFG group subjects showed a trend to be leaner. In addition, the HOMA-IR of the isolated IFG group was significantly higher (2.30±0.12 vs. 1.89±0.13, p=0.028), the WBISI between two groups was not different (10.8±0.67 vs. 12.4±0.78, p=0.123), and these findings suggest that the difference in insulin resistance between two groups was mainly caused by hepatic resistance. For the insulin secretory indices, the IGI (140.3±10.6 vs. 91.0±11.5, p=0.002) and the AUC I/G 120 (65.2±3.4 vs. 54.0±4.0, p=0.037) were significantly higher for the isolated IFG group. This significance of the insulin secretory capacity between each group did not change after an adjustment for insulin resistance (IGI/WBISI) or the disposition index (IGI X WBISI). In conclusion, following the use of the OGTT, it was found that significant metabolic differences in insulin sensitivity and insulin the secretory capacity between the isolated IFG group and the isolated IGT group exist. [ABSTRACT FROM AUTHOR]

The commonly used relationship between HbA1c (A1c) and the mean plasma glucose (MPG) concentration is based on evidence from the DCCT. However, as the MPG is measured infrequently from capillary blood, its accuracy has some limitations. A recent study on the correlation between the A1c and the MPG measured in 12 diabetic volunteers using CGMS (Medtronic MeniMed, USA) found that the MPG estimate for an A1c of 7% was about 140 mg/dL, which is quite different from the result of the DCCT. In this study, we performed a retrospective analysis of the correlation between the A1c and the MPG from blood glucose measured using CGMS of 145 diabetic subjects. Among these patients, 74 subjects who showed no significant changes in their medication within 3 months of CGMS measurement were chosen as the final enrolled subjects, and the A1c levels of the subjects were measured within 1 month of CGMS measurement. We also investigated that the proportion of CGMS measured glucose ≥ 180 mg/dL and the proportion of CGMS measured glucose <60 mg/dL in each subject. For the study results, the study subjects mean age was 53.8±16.9 years, and the mean diabetes duration was 11.9±7.1 years, and most (91.8%) of the subjects had type 2 diabetes mellitus. The subjects mean A1c level was 8.32±1.77% and their mean MPG measured by CGMS was 185.7±54.2 mg/dL. The mean MPG value measured using a glucometer was 194.1±53.9 mg/dL and the correlation between the former and latter values were high (R=0.96). A linear regression analysis results showed that the correlation between MPG and A1c measured using CGMS could be estimated by the formula (Adjusted for R = 0.60) and accordingly a 7% A1c level would estimate a MPG concentration of 161.0 mg/dL. Furthermore, the MPG values showed a significant alteration with a change in the A1c levels. With an increasing Ale level of subjects, a significant rise was seen in the proportion of CGMS measured glucose ≥ 180 mg/dL and with a decreasing Ale level, a significant rise was seen in the proportion of CGMS measured glucose < 60 mg/dL (p<0.05). Therefore the cut off values for the A1c level and MPG concentration, where the proportion of CGMS measured value that maintained between 60∼180 mg/dL over 90%, were estimated using the ROC curve; an estimate of the A1c level at 6.25% and the MPG at 145.5 mg/dL were calculated. [ABSTRACT FROM AUTHOR]