Use of insulin for 50 years or more in North Canterbury, New Zealand.

Previous reviews of diabetic subjects using insulin for 50 years or more have been based on clinic populations or on individuals receiving medals to mark this achievement. We interviewed all 11 subjects who had been on insulin for 50 years or more, identified from a population-based register of insulin users in North Canterbury, New Zealand. Seven of the 11 subjects had required treatment for micro- or macrovascular disease, but the functional level of the majority of survivors was nevertheless high. Diabetes had a major social impact on only one of the subjects interviewed.