Evolution of Glycemic Targets in Management of Diabetes

Abstract

How goals of diabetes management evolved over the last hundred years was largely dependent on the understanding of association of hyperglycemia with chronic complications, development of safe and effective therapeutic options and monitoring capabilities. Insulin ended the era of death in type 1 diabetes (T1D) but an era of chronic complications emerged. The medical community and policy makers were not convinced that near normal glycemia would prevent these complications. Diabetes Control and Complication Trial (DCCT) has a huge impact on how diabetes is managed today, hemoglobin A1C (A1C) of less than 7% emerged as a main therapeutic objective. However DCCT and later United Kingdom Prospective Diabetes Study (UKPDS) in type 2 diabetes (T2D), failed to show a safe lower cutoff where microvascular complications could be maximally reduced without additional risk of hypoglycemia. Moreover macrovascular complications could not be adequately addressed in these study populations. An over enthusiastic approach in the Action to Control Cardiovascular Risk in Type 2 Diabetes (ACCORD) trial resulted in an increase in overall and cardiovascular mortality, this led to concept of individualization of glycemic targets and “lower the better” is not appropriate for everyone. At the same time the follow up epidemiological data of DCCT and UKPDS reveal that good glycemic control earlier has long term benefits, the concept of legacy effect and led to the idea of “earlier the better”. Later advances in therapeutic options and monitoring capabilities have made it possible to safely achieve intensive glycemic goals, however widespread availability and cost precludes its common use.