Comment on: Godsland IF, Jeffs JAR, Johnston DG (2004) Loss of beta cell function as fasting glucose increases in the non-diabetic range. Diabetologia 47:1157–1166

Excerpt

For more than two decades I have awaited data such as those published by Godsland and co-workers [1] in the July issue of your journal. Although they focused primarily on the identification of the early disturbances that occur in the natural history of type 2 diabetes (the progressive loss of the first, and then of the second phase of insulin response), it seems of great importance to me that these changes occur at blood glucose levels between 5.0 and 5.4 mmol/l. This is well within the range considered as normal, even after the latest modifications of the higher limits of the definition for IFG proposed by the American Diabetes Association in 2003 [2], i.e. from 6.1 to 5.5 mmol/l. The rationale behind this decision was the increased risk of progression to clinical overt diabetes and cardiovascular events of individuals with fasting plasma glucose levels between 5.5 and 6.1 mmol/l, as compared with subjects with levels below 5.5 mmol/l. To these two arguments, I would add another, which is of physiological significance. Continuous glucose monitoring in non-diabetic individuals [3] provided evidence that, for an apparently healthy person, normal glycaemia could be considered the blood glucose value, which, when exceeded, is followed by a beta cell response aiming to bring blood glucose back to basal levels. From this viewpoint, normal values may in some cases fall well below 5.5 mmol/l and even below 5 mmol/l. …