Fasting and postprandial plasma glucose contribution to glycated haemoglobin and time in range in people with type 2 diabetes on basal and bolus insulin therapy: Results from a pooled analysis of insulin lispro clinical trials

AIMS: To investigate the interrelations between glycaemic metrics of fasting plasma glucose (FPG), postprandial glucose (PPG), glycated haemoglobin (HbA1c), and percentage of time in target range 3.9 to 10.0 mmol/L (%TIR) in patients on insulin therapy. MATERIALS AND METHODS: A pooled analysis was conducted using datasets extracted from an integrated database of insulin lispro clinical trials (Eli Lilly and Company). Studies in patients with type 2 diabetes on basal‐bolus or basal‐plus insulin therapy, and with ≥7‐point self‐monitored blood glucose profiles were included in the analysis. A multivariate regression model was used to quantify the contribution of FPG and PPG change to the change in HbA1c and %TIR. In addition, a linear regression model was used to describe the relationship between %TIR and HbA1c. RESULTS: Five studies encompassing 1572 patients met the criteria for inclusion. On average, a 1‐mmol/L change in FPG was associated with 2.7 mmol/mol (0.25%) change in HbA1c (range 2.0 to 2.8 mmol/mol [0.18%–0.26%]; all P <0.0001), and a 1‐mmol/L change in PPG with 1.8 mmol/mol (0.16%) change in HbA1c (range 1.2 to 2.1 mmol/mol [0.11%–0.19%]; all P <0.01). Furthermore, a 1‐mmol/L reduction in FPG and PPG was associated with an increase in TIR of 6.5% (range 5.8%–9.2%) and 5.3% (range 4.1%–8.7%), respectively, all P <0.0001. A decrease in HbA1c of 10.9 mmol/mol (1%) corresponded with an increase in TIR of 8.3%, on average. CONCLUSIONS: In patients with type 2 diabetes on basal‐bolus or basal‐plus insulin therapy, management of both FPG and PPG is important for achievement of HbA1c and TIR goals.