Testing

The American Diabetes Association recommends that all insulin-treated diabetics (multiple insulin injections or insulin pump therapy), regardless of the affliction with type 1 or type 2 diabetes, should optimally perform self-monitoring of blood glucose (SMBG) three or more times daily. For patients using less frequent insulin injections, noninsulin therapies, or medical nutrition therapy (MNT) alone, SMBG may be useful in achieving glycemic goals by monitoring at least two times daily and over the course of a week monitor at different times of the day.31 Glucose levels peak at approximately one hour after the start of a meal and the return to pre-prandial (e.g., prior to eating a meal) levels within two to three hours. To achieve post-prandial (e.g., after eating a meal) glucose targets, post-prandial SMBG may be appropriate to determine the insulin response, which can be diminished or absent in type 2 diabetes.32 Continuous glucose monitoring may be a supplemental tool to SMBG for selected patients with type 1 diabetes, especially those with hypoglycemia unawareness.31,32 The hemoglobin A1C test (HbA1c) is recommended at least two times a year in patients who are meeting treatment goals and who have stable glycemic control. It is performed more frequently for patients whose therapy has changed or who are not meeting glycemic goals. The binding of glucose to hemoglobin is irreversible allowing the test to provide an average blood glucose level over the four month lifespan of the red blood cells, which equates to the preceding 60 – 90 day period.33 Normal HbA1c is (<) 6%. Increasing levels correlate with the development of diabetic complications. The 2008 American Diabetes Association recommendations for diabetics are A1C levels (<) 7% for non-pregnant adults in general. Epidemiologic studies have suggested there may be an incremental benefit to lowering A1C from 7% into the normal range of (<) 6%. Therefore, the A1C goal for selected individual patients is as close to normal (<) 6% as possible without significant hypoglycemia. The A1C goals are less stringent for children and patients with a history of severe hypoglycemia, limited life expectations, or longstanding diabetes and minimal microvascular complications.14,32,34 Lowering A1C to an average of 7% has clearly been shown to reduce microvascular and neuropathic complications of diabetes and, possibly, macrovascular disease.34