Within-subject biological variation of glucose and HbA1c in healthy persons and in type 1 diabetes patients

Background: Several articles describing within-subject biological variation of fasting glucose and HbA(1c) in healthy populations have been published, but information about biological variation of glucose and HbA(1c) in patients with type 1 diabetes is scarce. It is reasonable to assume that type 1 diabetics differ from their healthy counterparts in this matter. The aim of our study was to estimate the biological variation of glucose and HbA(1c) in healthy subjects and in patients with type 1 diabetes. Methods: Fifteen healthy individuals and 15 type 1 diabetes patients were included. Biological variations were calculated based on blood samples collected weekly for 10 consecutive weeks from the healthy and the eligible of the type 1 diabetes patients. Results: The within-subject variations of glucose were approximately 5% in healthy individuals and 30% in diabetes patients, and for HbA(1c) they were 1.2% in healthy individuals and 1.7% in diabetes patients. Conclusions: In conclusion, we found a high within-subject biological variation of glucose in diabetes patients as expected compared to healthy individuals (30% vs. 5%). The short-term (2 months) within-subject biological variation of HbA(1c) did not differ significantly between well regulated type 1 diabetes patients and healthy individuals (1.7% vs. 1.2%).