, Volume 48, Issue 7, p 1418
Date: 03 Jun 2005

Coffee, diabetes and insulin sensitivity

This is an excerpt from the content

To the Editor: Two recently published studies have suggested that habitual consumption of coffee reduces the risk of developing type 2 diabetes [1, 2]. The mechanisms involved are unknown but are likely to relate to the effects of caffeine on insulin action. Although acute studies show that caffeine loading is associated with a reduction in insulin sensitivity, this effect appears to be lost following sustained consumption [3].

In type 1 diabetes, caffeine has been reported to enhance the symptomatic and hormonal responses to hypoglycaemia [4], but its effects on insulin sensitivity are unknown.

In 1999 a 33-year-old man, a long-term consumer of coffee, was converted to continuous subcutaneous insulin infusion as part of a clinical trial. He developed type 1 diabetes at the age of 3, but apart from diabetic retinopathy, has remained well with HbA1c levels of between 7 and 8%. Recently, on two occasions separated by 2 weeks, he consumed his usual breakfast (a bowl of cereal) but kept the