STOCKTON-ON-TEES, UNITED KINGDOM. Impaired glucose tolerance (IGT) is a rapidly growing health problem in the western world. Studies in the UK have shown that around 17 per cent of people between the ages of 35 and 65 years have IGT. The diagnosis of IGT, also known as insulin resistance, is made if fasting glucose levels are between 110 mg/dL (6.1 mmol/L) and 126 mg/dL (7.0 mmol/L). It is estimated that over half of all people with IGT develop type 2 diabetes within 10 years of diagnosis. People with IGT also have double the risk of developing cardiovascular disease than do people with normal fasting glucose levels. Dietary and lifestyle changes are very effective in reducing the risk of IGT progressing to diabetes with some studies having found a 58 per cent reduction in risk of progression. No pharmaceutical drugs have been found effective in halting the progression from IGT to diabetes.
A group of researchers from the University of Durham has just completed a survey of 34 general
practitioners to determine what they know about IGT and how they treat it. All participants knew what IGT
was, but few were aware that it progresses to type 2 diabetes and markedly increases the risk of
cardiovascular disease. More than half the group had no idea how many of their patients had IGT and, of
those who hazarded a guess, most thought the prevalence was less than 1 per cent (actual prevalence is 17
per cent). The doctors had no specific plan for dealing with the condition and few were aware that dietary
and lifestyle modifications are highly effective in halting IGT in its tracks. Several would prescribe metformin
(Glucophage) even though there is no evidence that it would be of any benefit. The Durham researchers
conclude that, "Awareness of impaired glucose tolerance needs to be raised, and guidelines for
management are needed".