This paper investigated the evidence for and against intensified glucose-lowering therapy in type 2 diabetes. There is no question that glucose control is essential to prevent mortality by maintaining an HbA1c around 7.5%. The interrogation concerns the benefits, costs and risks of lowering HbA1c to ~7% or below in type 2 diabetes. Among the major cardiovascular outcome studies of intensive glycemic control, none found a significant reduction in cardiovascular events in intensively treated patients. When the studies were combined, it was reported that nonfatal coronary episodes were reduced, whereas stroke, cardiovascular mortality and total mortality were unaffected. Epidemiological estimates suggested modest improvements in life expectancy, but highlighted the fact that these benefits will be greatest in younger and healthier patients. However, regarding microvascular complications, the UKPDS and DCCT studies showed that a 1% reduction in HbA1c reduced the risk of these complications by about 25%. Thus, hyperglycemia is a substantially weaker risk factor for cardiovascular disease than cholesterol or blood pressure, and glucose-lowering interventions are correspondingly less effective. Good glucose control does offer protection against microvascular complications, but the added benefits of an HbA1c of 7% decreased with age and life expectancy. Therefore, authors suggest that efforts and resources should be directed to those with higher levels of HbA1c who have much more to benefit from attention to their glucose control.
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