Can glycaemic variability, as calculated from blood glucose self-monitoring, predict the development of complications in type 1 diabetes over a decade?

Aims: Is glycaemic variability an independent risk factor for the development of microvascular complications in addition to average glycaemia, as assessed by glycated haemoglobin (HbA1c)? In this study, an 11-year follow-up was carried out in patients with type 1 diabetes. The standard deviation of blood glucose (SDBG) concentration, an index of glycaemic variability, was calculated from self-monitored blood glucose data at baseline. Methods: A total of 100 patients were randomly selected from 442 consecutive type 1 diabetic patients attending our outpatients clinic. SDBG was calculated from 70 measurements taken over a period of four weeks. Onset and progression of micro- and macrovascular complications were recorded over the 11-year follow-up. Results: As expected, the prevalence of complications increased over time. Statistical analyses showed that HbA1c was an independent predictor of the incidence (P = 0.004) and prevalence (P = 0.01) of nephropathy. SDBG was found to be a predictor of the prevalence of peripheral neuropathy (P = 0.03), and showed borderline significance in predicting the incidence of peripheral neuropathy (P = 0.07). SDBG was also a highly significant predictor of hypoglycaemic unawareness (P = 0.001). Conclusions: We conclude that variability of blood glucose may be important in the development of peripheral neuropathy in patients with type 1 diabetes, and that the nervous system may be particularly vulnerable to glycaemic variability. © 2008 Elsevier Masson SAS. All rights reserved.