Blockade of chlorpropamide-alcohol flushing by indomethacin suggests an association between prostaglandins and diabetic vascular complications.

Chlorpropamide/alcohol flushing (CPAF), found in many patients with non-insulin-dependent diabetes (NIDD), can be blocked by indomethacin in most patients who are free of vascular complications but not in those with such complications. Since indomethacin is a prostaglandin inhibitor this finding suggests that prostaglandins may be involved in the aetiology of vascular diseases in NIDD. All 6 pairs of identical twins with CPAF, of whom 2 pairs were disocrdant for diabetes, were concordant for indomethacin blocking, which suggests that the block has a genetic basis. The difference in the response of CPAF to indomethacin in diabetic patients with and without vascular complications is probably the first indication of a metabolic difference between these two types of patient.