Does knowledge of islet cell antibody status help in managing diabetes presenting in middle and old age?

It has been suggested that screening all patients with diabetes diagnosed in later life for islet cell antibodies (ICA) would help predict insulin dependence. We have surveyed the case notes of 55 patients (22 male; ages 37-88 years) who were found to be ICA positive over a 9-year screening period to assess what contribution knowledge of ICA status made to their management. Forty-two patients had been put on insulin (half within 6 months of diagnosis and the rest after up to 6 years). Of the 13 patients not on insulin, six were on diet alone and seven on oral hypoglycaemic agents after a median follow-up of 3 years. In 37 of the 42 patients, insulin treatment was started for clinical rather than immunological reasons (diabetic ketoacidosis, ketonuria, weight loss and/or severe symptoms). Five patients were started on insulin because of ICA status when there was no compelling reason on clinical grounds. Knowledge that seven non-insulin-treated patients were ICA positive made doctors reluctant to discharge them from clinic. The data suggest that routine ICA estimation in this age group is unnecessary, as the decision to treat with insulin is best made on clinical grounds, and ICA estimation can lead to unwarranted insulin treatment, or anxiety in patients and doctors who are aware of a positive result.