Software programs allow for review of glucose data, which can assist in identifying trends not appreciated by typical SMBG testing (such as nocturnal hypoglycemia and meal-time excursions). This allows for adjustment of insulin regimens to reduce the incidence of these events.
Q: Can CGM replace SMBG?
While CGM can provide much more detail regarding glucose trends and patterns, it is not a replacement for SMBG. CGM should not be used as a replacement for SMBG to dose insulin for meal- or activity-related adjustments. All dosing decisions should be based on the SMBG.
Currently, CGM is indicated for patients 18 or older, in conjunction with SMBG for the purpose of improving glycemic control:
• to identify and aid in management of glycemic patterns not recognized with typical SMBG
• to prevent glycemic excursions of hypoglycemia and hyperglycemia.
Its use is supported by ADA and AACE guidelines for glucose monitoring.
Q: Who would benefit from CGM?
Suitable candidates for CGM include those with a high degree of glycemic variability, those with hypoglycemic unawareness, shift workers, patients who use insulin pumps, athletes, and women who are planning to become or are pregnant. Patients should work closely with their health care team and perform regular SMBG.
It has been suggested that patients need comprehensive training and follow-up visits to fully understand the large amount of data that they can be confronted with, in order to fully benefit from these devices.6 While the accuracy is improving, there are a few limitations to this technology, including false alarms. Studies have also shown a positive correlation between sensor wear time (hours per week) and greater reductions in A1C.5
Conclusion
Glucose monitoring is a necessary tool—for patients as well as providers—that assists in identifying how patients’ lifestyles affect their diabetes.