Glycemic control in type 2 diabetes: from medication nonadherence to residual vascular risk

Despite the availability of many new treatment options for type 2 diabetes, the proportion of patients achieving the HbA1c target < 7.0% remains around 50%. We put forward the hypothesis that the unchanged HbA1c results, observed in the last decade in type 2 diabetes patients, are also a consequence of medication nonadherence and clinical inertia. Poor medication-taking behavior is usually defined as medication nonadherence and is responsible for uncontrolled hemoglobin A1c level in 23% of cases. Medication nonadherence may also affect clinical outcomes, as diabetic patients with good adherence (≥80%) had a significant 10% lower rate of hospitalization events and a significant 28% lower rate of all-cause mortality when compared with patients with poor adherence (<80%). Residual vascular risk may be defined as the risk of macrovascular (major cardiovascular events) and microvascular (retinopathy, nephropathy, neuropathy) complications that remains after intensive and successful glycemic control in type 2 diabetes. For major cardiovascular events, risk reduction following intensive glycemic control is 9% and, therefore, residual vascular risk is 91%. For microvascular complications, as nephropathy, residual vascular risk is as high as 80%. Residual vascular risk remains high in type 2 diabetes despite intensive glycemic control. Medication nonadherence by the diabetic patient and clinical inertia by the clinician may have contributed to the high level of residual vascular risk (both macro and microvascular) of type 2 diabetic patients.