Fructosamine concentrations in general population of Kawerau.

We measured fructosamine concentrations in nonfasted serum from 7094 residents (82.8% of the estimated population) of Kawerau, New Zealand, including 65 known diabetic patients (prevalence of 0.92%). Fructosamine results showed a trimodal frequency distribution, with cutting points corresponding to 5th and 95th percentile values. Forty-two diabetic individuals had levels that exceeded the 95th percentile. These individuals had more severe metabolic abnormalities, characterized by lower plasma C-peptide and elevated fasting plasma glucose concentrations. Mean fructosamine values also showed a significant increase with age and a highly significant age-ethnic interaction that paralleled the higher frequency of diabetes in older age groups and among elderly Maori people. However, as a screening method in the general population, fructosamine measurement was diagnostically deficient because of a weak correlation with serum albumin. Arithmetic correction for albumin concentration in the sample did not increase the diagnostic usefulness of the test.