About 90% of the 30 million Americans with diabetes in the U.S. are managed by primary care clinicians. Although more than 252 different pharmacologic treatment options are available to treat type 2 diabetes, less than half of our patients are able to achieve the recommended targeted A1C of less than 7%.
A product theatre at American Academy of Family Physicians Family Medicine Experience (AAFP FMX) addressed a paradigm shift for intensifying diabetes management within the primary care setting using continuous glucose monitors (CGM). Although the one hour session focused on the Freestyle Libre, the attendees were introduced to the important and novel concept of how technology can rapidly reduce the risk of hypoglycemia, minimize post meal glycemic elevations, and improve glycemic variability. Poorly controlled diabetes can increase the risk of long-term diabetes related complications such as coronary artery disease, retinopathy, neuropathy, and nephropathy.
Unlike traditional self-monitoring of blood glucose, CGM devices provide information about an individual’s current glucose level, glucose trends, and, importantly, the direction and velocity of their changing glucose through use of trend arrows. Daily use of CGM allows patients to make more informed decisions when calculating insulin dosages and facilitates greater understanding of how food, medication, exercise, stress, and other factors impact their glycemic control. Retrospective analysis of CGM data allows patients and their clinicians to identify glycemic patterns that may indicate the need for therapy adjustments and/or lifestyle and behavior changes. During the past five years, several CGM systems have been introduced, each with its own unique features and characteristics (Figure 1).
After placing the sensor on one’s body, patients will begin receiving data regarding glucose values and trends, times during each day when hypoglycemia occurs, and how often one achieves glucose values within the range of 70–180 mg/dL. The Freestyle Libre patient may use a cell phone or a “reader” to assess their real time glucose values. Each patient should utilize CGM to reduce the risk of hypoglycemia to less than 3%, optimize one’s “time in target” to 70–180 mg/dL at least 50% of the time the sensor is worn, and minimize daily highs and lows associated with interstitial glucose readings. Patients with type 2 diabetes typically scan their Freestyle Libre eight times daily versus just three times daily when using finger stick glucose meters.
Visual trend analysis provides the user with real-time data, which may be utilized to reduce the risk of hypoglycemia, mitigate postprandial excursions and reduce glycemic variability. Although A1c testing provides a surrogate measure of glycemic control, patients with a targeted A1c of 7% could experience glucose levels within the range of 80–180 mg/dL or 50–260 mg/dL. Thus, the A1c does not provide the clinician or the patient with any specific guidance for safe and effective therapeutic interventions. Glycemic variability increases the risk of hypoglycemia and tends to drive long-term diabetes related complications via endothelial cell oxidative stress. Day-to-day fasting glucose variability was significantly associated with severe hypoglycemia, all-cause mortality, and major adverse cardiovascular events.
CGM is a powerful tool for individualizing diabetes care and provides both the patient and clinician with real-time and retrospective data which can be used to encourage behavioral and targeted therapeutic interventions. The ability to make immediate adjustments to control blood glucose values can be motivating to the patient and rewarding for clinicians. Patients with diabetes should be prescribed medications which are safe, effective, and result in minimal risk of hypoglycemia or weight gain.
Because approximately 90% of patients with diabetes are managed within primary care, the inclusion of CGM into our practices will likely improve the overall glycemic control of our nation’s diabetes population.