Multiple HbA1c targets and insulin analogues in type 2 diabetes: a systematic review

Insulin analogues are increasingly used in patients with type 2 diabetes. We performed a systematic review of randomized controlled trials (RCTs) to assess the role of insulin analogues to reach different hemoglobin A1c (HbA1c) targets (from 6.5% to 8%) in type 2 diabetic patients.

RCTs involving insulin regimens (basal, prandial, biphasic, and basal-bolus) with insulin analogues in type 2 diabetes were identified through electronic searches (MEDLINE, EMBASE, CINAHL, and The Cochrane Library) through August 2010. We included any study arm of RCTs if they were at least 12 weeks in duration, and reported HbA1c as an outcome and the proportion of diabetic patients reaching the HbA1c target of <7%. The proportion of patients with HbA1c <6.5%, <7.0%, <7.5%, and <8.0% was estimated using mean and standard deviation of HbA1c at the end of treatment.

We identified 53 RCTs, with 92 arms, and 32,689 patients. The proportion of patients at target was highest with the basal-bolus regimen, and ranged from 27.8% (95% CI, 22.2-34%) for the HbA1c target <6.5% to 88% (CI 83-92%) for the HbA1c target <8%. Biphasic insulin regimen ranked second at any HbA1c target, while prandial and basal regimens alternated across different HbA1c targets.

At any HbA1c target, basal-bolus insulin regimens with insulin analogues obtained the best results, which may be useful for detailing the best treatment effect in individual patients.