Monitoring glycemic control: the importance of self-monitoring of blood glucose.

Several methods, each with differing utility and limitations, exist for monitoring glycemic control. Hemoglobin A1c (HbA1c) is considered the standard measure of long-term glycemic control, and HbA1c levels are strongly associated with complications of diabetes. However, HbA1c does not provide "real-time" information about individual hyperglycemic or hypoglycemic excursions. Urine glucose testing is noninvasive and inexpensive, but it is dependent on the patient's individual renal threshold and can only detect glucose concentrations above this threshold. As such, urine testing cannot be recommended for diabetes management that aims for near-normoglycemia. Self-monitoring of blood glucose (SMBG) complements HbA1c by providing real-time blood glucose data. It is an educational tool for both patients and their healthcare providers to understand the effects of diet, exercise, and medications on day-to-day glycemic control. However, guidelines from various international diabetes organizations vary in their level of specificity regarding the frequency and timing of self-monitoring. SMBG should be implemented for all patients as part of an overall diabetes management plan that includes specific instruction on how, when, and why to test.