Optimal management of type 2 diabetes: the evidence

This paper reviews the evidence in relation to the optimal target for HbA1c and outlines a global treatment algorithm for people with type 2 diabetes. While most guidelines recommend a general HbA1c target of 7%, recent large scale intervention studies have examined the potential benefits of lower targets. These studies have generally shown that lower HbA1c targets provide no macrovascular benefits and limited effects on microvascular complications while increasing rates of hypoglycaemia. Overall these studies do not support a general HbA1c target lower than 7.0%. However an individual's HbA1c target should be set and reviewed taking into account treatment benefits, safety, and tolerability. This may mean that an HbA1c target lower than 7% is appropriate for some when it can be easily and safely achieved but equally a higher HbA1c target may be appropriate in others. Clinicians and consumers are fortunate in having a wide range of pharmacological agents available to treat hyperglycaemia, however access to many of these options is limited in many middle and low income countries. Developing treatment algorithms is complex for several reasons. The major limitation is the limited evidence base for choosing particular treatment options or combinations of medications. However it is possible to derive a generic evidence-informed consensus algorithm which considers availability, access and cost of medications which can be adapted for local country use.