Background: Early initiation of insulin therapy has widely been associated with numerous benefits, including improved glycaemic control and reduced long-term risk of developing microvascular diseases. Biphasic insulins offer a convenient option for insulin initiation, addressing both basal and postprandial insulin requirements with one injection, making them relatively simple for patients to dose. Development of biphasic insulin aspart (BIAsp) has further offered improved postprandial glycaemic control and lower rates of nocturnal and major hypoglycaemia than biphasic human insulin.
Methods: The safety and efficacy of the 30/70 rapid-acting/intermediate-acting formulation of BIAsp (BIAsp 30) in patients with type 2 diabetes was examined in the IMPROVE study, a 26-week, international, observational trial. In this subanalysis, baseline clinical factors that predicted treatment success, defined as HbA1c <7% (<53 mmol/mol) without experiencing hypoglycaemia after 26 weeks on BIAsp 30 therapy, were assessed.
Results: The composite endpoint was defined for 44,010 (77%) patients from the total cohort of 57,478, and 28,696 of these were included in the statistical examination. The results of the analysis suggest that those with lower baseline HbA1c of ≤8% (≤64 mmol/mol), shorter duration of diabetes at baseline (<5 years) and no incidence of major hypoglycaemia at 13 weeks, or minor hypoglycaemia at 4 weeks, before the beginning of the trial were more likely to achieve treatment success.
Conclusion: Lower baseline HbA1c, shorter duration of diabetes and no incidence of hypoglycaemia up to 13 weeks prior to initiation are predictors of achieving HbA1c <7% without hypoglycaemia with a BIAsp 30 regimen. These results suggest that it is easier to reach target without hypoglycaemia with BIAsp 30 when prescribed earlier. As this was an observational study, lack of control groups or randomisation, as well as varying clinical practices in study countries, potentially introduced bias.
Trial registration: ClinicalTrials.gov NCT00659282.