This study aimed to compare the patterns of insulin secretion and resistance between Korean subjects in the 1990s and 2000s.
Insulin secretion and resistance indices were calculated from subjects who underwent 75-g oral glucose tolerance tests in the year 1997 to 1999 and 2007 to 2011 at the Seoul St. Mary's Hospital, Korea.
A total of 578 subjects from the 1990s (mean age, 48.5 years) and 504 subjects from the 2000s (mean age, 50.2 years) were enrolled. Compared with the subjects from the 1990s, those from the 2000s exhibited increased insulin resistance (increased homeostatic model assessment for insulin resistance), and reduced insulin sensitivity (reduced Matsuda index and quantitative insulin sensitivity check index), regardless of their glucose tolerance status. However, insulinogenic index did not reveal significant differences between the 2 decades in subjects with or without diabetes. A distinct relationship was confirmed between Matsuda index and total area under the curve (insulin/glucose) in each glucose tolerance group. The mean product of the Matsuda index and the total area under the curve (insulin/glucose) as well as the oral disposition index, was lower in subjects with normal glucose tolerance from the 2000s than in those from the 1990s.
After rapid economic growth and changes in lifestyle patterns, insulin resistance has worsened across the glucose tolerance status; however, the insulin secretory function remained unchanged, which resulted in an increase in the susceptibility to the development of type 2 diabetes mellitus among Korean subjects without diabetes. We could not rule out the potential selection bias and therefore, further studies in general Korean population are needed.
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Subjects with normal glucose tolerance (NGT) who have a high 1-hour postload plasma glucose level (≥155 mg/dL; NGT 1 hour-high) have been shown to be at higher risk for type 2 diabetes than subjects with NGT 1 hour-low postload plasma glucose level (<155 mg/dL). We compared β-cell function in subjects with NGT 1 hour-high, NGT 1 hour-low, and impaired glucose tolerance (IGT).
We classified subjects into NGT 1 hour-low (
Insulin sensitivity was comparable between the subjects with NGT 1 hour-high and NGT 1 hour-low. The β-cell function with/without adjusting insulin sensitivity was significantly different among the three groups. The IGI (pmol/mmol) was 116.8±107.3 vs. 64.8±47.8 vs. 65.8±80.6 (
Among Korean subjects with NGT, those who have a higher 1-hour postload glucose level have a compromised insulin-sensitivity adjusted β-cell function to a similar degree as IGT subjects.
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Acute postprandial hyperglycemia is an important affector for atherosclerosis in subjects with glucose intolerance. We analyzed the relationship of brachial-ankle pulse wave velocity (baPWV) with fasting and post-challenge plasma glucose levels according to different time points during oral glucose tolerance test (OGTT).
In 663 subjects with fasting hyperglycemia, 75 g OGTT were performed to confirm the glucose tolerant status, and fasting, post-challenge 30-minute and 120-minute glucose levels were measured. Anthropometric measurements were done, and fasting lipid profiles were measured. baPWV were measured in all subjects and the relationship between fasting, 30- and 120-minute post-challenge glucose levels and baPWV were analyzed.
Among the participants, 62.9% were prediabetes and 31.7% were diabetes. Mean baPWV value was significantly higher in subjects with diabetes compared with prediabetes group. In bivariate correlation analyses, age, blood pressure, total cholesterol, low density lipoprotein cholesterol, 30-minute and 120-minute post-challenge glucose levels showed significant positive correlation with baPWV value. In multiple regression analysis, 30-minute post-challenge glucose level was a weak but significant determinant for mean baPWV value even after adjustment for other confounding variables.
Postprandial hyperglycemia, especially 30-minute glucose levels showed significant correlation with baPWV in subjects with fasting hyperglycemia. These results can imply the deleterious effect of acute hyperglycemic excursion on arterial stiffness in subjects with glucose intolerance.
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