Effect of the Frequency of Self-Monitoring Blood Glucose in Patients with Type 2 Diabetes Treated with Oral Antidiabetic Drugs—A Multi-Centre, Randomized Controlled Trial

Objective Recommendations on the frequency of self-monitoring of blood glucose (SMBG) vary widely among physicians treating patients with type 2 diabetes (T2D). Aim of this study was to investigate two testing regimen of SMBG in patients with stable metabolic control. Research Design and Methods Patients with T2D treated with oral antidiabetic drugs were randomized to two groups: either one SMBG (low) or four SMBG (high) per week. Subjects were followed up after 3, 6 and 12 months. Primary outcome parameter was the change in HbA1c between baseline and 6 months. Primary outcome criterion was tested by a one-sided t- test for non- inferiority. Secondary outcome parameters were safety, compliance and HbA1c at 3 and 12 months. Results There were no differences in the 202 subjects for demographic and sociodemographic parameters and drug treatment. HbA 1 c (%) at baseline was similar in both groups (7.2±1.4 vs. 7.2±1.0). Non- inferiority was demonstrated for the low group (p = 0.0022) with a difference from baseline to 6 months of 0.24 in the low and of 0.16 in the high group. Compliance with the testing regimen was 82–90% in both groups. There were no statistical significant differences for compliance, HbA 1 c at 3 and 12 months and serious adverse events (SAE). Conclusion One SMBG per week is as sufficient and safe as four SMBG per week to maintain HbA 1 c in non-insulin treated T2D close to metabolic target. The results of this study are in contrast to current international consensus guidelines. Trial Registration Controlled-Trials.com ISRCTN79164268