To evaluate factors associated with reaching or not reaching target glycated haemoglobin (HbA_1c) levels by analysing the respective contributions of fasting hyperglycaemia (FHG), also referred to as basal hyperglycaemia, vs postprandial hyperglycaemia (PHG) before and after initiation of a basal or premixed insulin regimen in patients with type 2 diabetes.

This post-hoc analysis of insulin-naïve patients in the DURABLE study randomised to receive either insulin glargine or insulin lispro mix 25 evaluated the percentages of patients achieving a target HbA_1c of <7.0% (<53mmol/mol) per baseline HbA_1c quartiles, and the effect of each insulin regimen on the relative contributions of PHG and FHG to overall hyperglycaemia.

Patients had comparable demographic characteristics and similar HbA_1c and FHG values at baseline in each HbA_1c quartile regardless of whether they reached the target HbA_1c. The higher the HbA_1c quartile, the greater was the decrease in HbA_1c, but also the smaller the percentage of patients achieving the target HbA_1c. HbA_1c and FHG decreased more in patients reaching the target, resulting in significantly lower values at endpoint in all baseline HbA_1c quartiles with either insulin treatment. Patients not achieving the target HbA_1c had slightly higher insulin doses, but lower total hypoglycaemia rates.

Smaller decreases in FHG were associated with not reaching the target HbA_1c, suggesting a need to increase basal or premixed insulin doses to achieve targeted fasting plasma glucose and improve patient response before introducing more intensive prandial insulin regimens.