This raises the question of whether the proportion of dispensing doctors might be related to the incidence of diabetes in children. If drugs such as antibiotics were implicated in any way with the onset of diabetes, and if dispensing doctors prescribed them more liberally perhaps as a result of financial incentives, then it might be reasonable to expect to find a higher incidence of diabetes in country vs city children.

The North Western and Mersey regions, which both have a medium incidence of diabetes and yet a low number of dispensing doctors, are both, incidentally, regions with the highest number of prescriptions (excluding those dispensed by prescribing doctors) per person in England for 1981 and for 1990. They are also the regions with the greatest increase in the number of prescriptions per person in England between 1981 and 1990-an average increase of 25 per cent-compared with around 8.7 per cent for the four Thames regions over the same time period.

In addition, the NW Thames area [the Thames region with the lowest incidence of diabetes in under-15s during 1988] was also the region with the lowest number of prescriptions per person in 1981 and in 1990-5.6 and 5.9, respectively. By way of comparison, the SE Thames area (the Thames region with the highest incidence of diabetes) was the Thames region with the highest number of prescriptions per person for 1981 and 1990 (6.3 and 7.0, respectively).

Although these data do not include prescriptions issued by dispensing doctors, the percentage of dispensing doctors in both of these Thames regions is approximately the same. However, the SW Thames region, which has a low percentage of dispensing doctors (6 per cent), but ranked second highest for incidence of diabetes of the four Thames regions (see box, page 7), was reported in 1985 to have the highest rate of induced births in England (23.9 per cent), compared with an average of 17.2 per cent for the other Thames regions (Francome C. Changing Childbirth: Interventions in Labour in England and Wales. London: Maternity Alliance, 1989).

Since dispensing doctors are more liberal in handing out drugs, then it might be expected that an area with a high proportion of dispensing doctors would also have a high incidence of disease-which is indeed the case here. Furthermore, regions with a higher number of prescriptions per person also had a higher incidence of diabetes.

The idea that drugs can cause diabetes is not new. What is novel is the suggestion that there are drugs in common use that may be partly responsible for the epidemics currently seen in many industrialized countries today.

Lisa Landymore-Lim

Dr Landymore-Lim is a chemist who specializes in immunology. Visit her website at www.atomichealth.co.uk.