Paddock E, et al. – The aim of this study was to explore the correlation between 1 h plasma glucose concentration (1 h–PG) and 2–h plasma glucose concentration (2 h–PG) using gold standard methods for measuring insulin secretion and action. They further compared 1 h–PG and 2 h–PG as predictors of type 2 diabetes mellitus. It was noted that the 1 h–PG was correlated with important physiological predictors of type 2 diabetes and was as effective as 2 h–PG for predicting type 2 diabetes mellitus. The 1 h–PG is, thus, an alternative method of distinguishing individuals with an elevated risk of type 2 diabetes mellitus.

Methods

• Analysts recruited adult volunteers without diabetes, predominantly Native Americans of Southwestern heritage, who were involved in a longitudinal epidemiological study from 1965 to 2007, with a baseline OGTT that included measurement of 1 h–PG.
• In this analysis, group 1 (n = 716) underwent an IVGTT and hyperinsulinaemic–euglycaemic clamp for measurement of acute insulin response (AIR) and insulin–stimulated glucose disposal (M), respectively.
• Thereafter, some members of Group 1 (n = 490 of 716) and members of a second, larger, group (Group 2; n = 1946) were followed–up evaluate the establishment of type 2 diabetes (median 9.0 and 12.8 years follow–up, respectively).

Results

• The results of this study displayed that compared with 2 h–PG (r = –0.281), 1 h–PG (r = –0.384) was more closely correlated with AIR, whereas, compared with 1 h–PG (r = –0.340), 2 h–PG (r = –0.408) was more closely correlated with M.
• It was demonstrated that measures of 1 h–PG and 2 h–PG had similar abilities to predict type 2 diabetes, which did not change when both were included in the model.
• The findings showed that a 1 h–PG cut–off of 9.3 mmol/l served similar levels of sensitivity and specificity as a 2 h–PG cut–off of 7.8 mmol/l; the latter is used to define impaired glucose tolerance, a recognised predictor of type 2 diabetes mellitus.