Post-load glucose measurements in oral glucose tolerance tests correlate well with 1,5-anhydroglucitol, an indicator of overall glycaemic state, in subjects with impaired glucose tolerance

Abstract

Using both cross-sectional and longitudinal methods, we investigated the relationship between post-load serum glucose concentration in a 75 g oral glucose tolerance test (OGTT) and overall glycaemic state in subjects with impaired glucose tolerance (IGT). Glycaemic state was assessed by measuring glycated haemoglobin (HbA1c) and the serum concentration of 1,5-anhydroglucitol (1,5-AG). In the cross-sectional study, the concentration of 1,5-AG, while remaining within a normal range, was reduced to a degree proportional to the post-load glycaemic level. Although the correlation between HbA1c and post-load plasma glucose was relatively weak (r=0.281, P<0.001), a significant inverse correlation (r=-0.824, P<0.0001) was found between 1,5-AG and mean post-load plasma glucose concentration in 211 subjects with IGT. Fasting plasma glucose (r=-0.539, P<0.0001) and 2 h plasma glucose (r=-0.621, P<0.0001) were correlated with 1,5-AG less strongly than was post-load glycaemia. Both 1,5-AG and HbA1c were correlated weakly but significantly with the fasting insulin concentration. In the longitudinal study we measured 1,5-AG and mean post-load plasma glucose with an OGTT once yearly for 10 years in 15 subjects with IGT. Strong inverse correlations were seen between 1,5-AG and mean post-load plasma glucose in each subject (range of r values among subjects of -0.584 to -0.978). These findings suggest a close relationship between post-load plasma glucose concentration measured by OGTT and overall glycaemic state in subjects with IGT.

Glycated Hemoglobin Level Is Strongly Related to the Prevalence of Carotid Artery Plaques With High Echogenicity in Nondiabetic Individuals

“…However, postprandial glucose level is an important determinant of the HbA 1c levels in nondiabetic persons. 28 The relationship between glycemia and the formation of hard plaques could therefore reflect an association between daily postprandial glucose spikes and atherosclerotic processes in the arteries.…”

Correlation between baseline serum 1,5-anhydroglucitol levels and 2-hour post-challenge glucose levels during oral glucose tolerance tests

“…whose HbA1c levels are at or near the goal [7,8], and 1,5-AG levels have been reported to reflect postprandial glucose values in diabetic patients [9,10]. 1,5-AG levels are also considered a useful indicator of glycemic control, because they correlate with fasting plasma glucose and HbA1c levels [11,12], and they have been suggested to be a predictor of microvascular complications, such as diabetic retinopathy [13].…”

1,5-anhydroglucitol levels in type 2 diabetic and non-diabetic subjects in Southern Taiwan

“…Concentrations of AG were identical in diabetic patients with or without smoking, hypertension, micro-vascular complications including retinopathy, neuropathy, proteinuria, and macro-vascular complications. Non-smoking diabetic patients seemed to have higher levels of AG; however, the difference was close to the statistic significance (P= 0.06).The cutoff value estimated for detecting DM in our subjects is lower than that in the Japanese (14µg/ml) (4,15,20). The poor plasma glucose control, as well as the fact that the subjects were not selected from a community basis, and the long DM duration might explain the discrepancy between the Japanese and our patients.…”

“…The cutoff value estimated for detecting DM in our subjects is lower than that in the Japanese (14µg/ml) (4,15,20). The poor plasma glucose control, as well as the fact that the subjects were not selected from a community basis, and the long DM duration might explain the discrepancy between the Japanese and our patients.…”

“…Thus, blood glucose test, glycosylated hemoglobin (HbA1c), fructosamine and AG may be used to assess the degree of glycemia (13)(14)(15)(16)(17)(18)(19)(20). Compared with fructosamine or HbA1c, AG shows a much greater sensitivity to glycemic changes, which makes AG reliable in monitoring daily changes of glycemia (4).…”