Your article on human insulin (WDDTY, vol 11 no 8) raised some important issues relating to the mishandling of its introduction and the inability of some people to manage their diabetes using this form of insulin. Diabetes UK (formerly British Diabetic Association) continues to work on behalf of people with diabetes to ensure that animal insulin remains available in the UK.

However, we were concerned by a number of points made in the article. First, you asserted that people who switched from animal to human insulin found that their health deteriorated. A significant minority of people did have problems, some severe, but the anecdotal evidence suggests that the majority transferred successfully. In those with problems, most were overcome through dosage adjustments. Some transferred back to animal insulins; an estimated 10 per cent of those currently using insulin use animal varieties.

Reference was also made to a report analysing 3000 letters complaining about the adverse effects of human insulin. The BDA did commission a report to look at the cases of those who contacted us. The report was to be submitted for publication in the British Medical Journal but, on its completion in 1993, a decision was taken not to pursue this. As the number of people reporting problems with human insulin had fallen dramatically, it was believed that the report would cause unnecessary alarm in the people successfully using the human variety. Instead, the BDA published the main findings in a supplement to our members' magazine Balance, entitled 'The Insulin Debate' (Oct/Nov 1994).

The problems with the introduction of human insulin were exacerbated by a failure to listen more closely to the experiences of patients. Yet, it is important to remember that around 90 per cent of people using insulin in the UK use human varieties, with few reporting problems. It is, however, vital that the needs of those who cannot manage their diabetes with human insulins are met. To this end, healthcare professionals and patients need to be aware of what insulins are available, including animal varieties. Bill Hartnett, Diabetes UK