A target HbA1c between 7 – 7.7% reduces macrovascular events in T2D regardless of duration of diabetes – a meta-analysis of randomized controlled trials

ABSTRACT Introduction The target glycosylated haemoglobin (HbA1c) at which macrovascular benefits may be derived in type 2 diabetes (T2D) has never been clearly outlined. This meta-analysis was conducted on fifteen randomized controlled trials to highlight the association of HbA1c range with macrovascular events. Methods The association of different HbA1c clusters (intention to treat (ITT) and end-of-study [EOS]) range (less or equal than 6.5%, 6.6%–7.0%, 7.1%–7.7%) with macrovascular complications and also the combined effect of duration of T2D (< 10 years or ≥ 10 years) and HbA1c levels was assessed. Results Intensive glucose-lowering strategy resulted in a significant 13% reduction in non-fatal myocardial infarction (NFMI) (P=0.006). Based on HbA1c achieved, a significant 36% reduction in non-fatal stroke (P=0.008) and a 22% reduction in all-cause mortality (P=0.02) were observed in the group with HbA1c between 7.1% – 7.7% irrespective of diabetes duration. In the cohort, with diabetes duration <10 years, reduction of HbA1c in the range7.1% - 7.7% resulted in a significant 36% reduction in non-fatal stroke (NFS) (P<0.001). Conclusion This is probably the first meta-analysis highlighting the importance of treating patients with T2D to a target HbA1C of 7 – 7.7%, as this target is associated with reduction in macrovascular events.