This retrospective cohort-based study assessed the change in glycated haemoglobin A1C (HbA 1C) in patients with type 2 diabetes, with existing prescriptions for oral antidiabetic drugs (OADs), prescribed insulin versus those prescribed subsequent OADs. A cohort of patient records drawn from the The Health Improvement Network (THIN) database was stratified by maximum concurrent number of OADs. Of 128,568 unique patient records identified, 67.7% (n=87,057) had received at least one OAD, 17.4% (n=15,138) of these patients progressed to insulin therapy. Mean HbA1C at insulin initiation was 9.5% (one OAD), 9.6% (two), 9.7% (three) and 10.1% (four), with an average HbA 1C increase of 0.7% prior to insulin initiation. The greatest improvement in HbA1C was achieved with insulin therapy. A threshold HbA 1C value of 8.5% above which OAD escalation is unlikely to achieve a target HbA1C
≤ 7.0% is seen. In patients not achieving HbA1C targets with OADs only, insulin-based regimens should be considered in preference to adding more or multiple OADs.
Br J Diabetes Vasc Dis 2010;10:178—182.