Background: The effectiveness of insulin therapy to lower blood glucose levels in patients with type 2 diabetes (T2D) may depend on a variety of factors. This study aims to determine baseline parameters including body mass index (BMI) threshold that might predict responders to insulin therapy.
Methods: This was a retrospective UK population-based study derived from 358 general practices electronic dataset. We included all patients with T2D, diagnosed at the age of >18 years old and who were initiated on insulin from January 2000 to December 2006. Insulin responders were defined as HbA1c <7.5% and/or HbA1c reduction by >1% at 12 months postinsulin initiation.
Results: Results are expressed in mean (s.d.). A total of 6032 patients were identified. Baseline age was 63 years (11.7). In all, 61% of patients (3696) responded to insulin. At 1-year postinsulin initiation, HbA1c was significantly reduced (9.8 vs. 8.4%, p < 0.001) and weight increased (85.7 vs. 87.9 kg, p < 0.001). Using logistic regression model, older age (p < 0.001), lower BMI (p = 0.046), higher HbA1c (p < 0.001), basal-bolus insulin therapy and premixed insulin compared to basal insulin alone at baseline were independent predictors of responders to insulin. Gender and social class were not significant predictors of insulin responders. A BMI of <35.3 was derived as a cut-point for response to insulin (p = 0.038).
Conclusion: Overall, insulin therapy confers significant HbA1c reduction and weight increase in patients with T2D. The responsiveness to insulin therapy however appears to depend on baseline age, BMI, HbA1c and insulin regime. Clinicians should take these factors into consideration when making a decision to initiate insulin therapy in patients with T2D.
© 2010 Blackwell Publishing Ltd.