Get Adobe Flash player
Blood Glucose Monitoring Advantages and Disadvantages of Realtime Continuous Glucose Monitoring in People with Type 2 Diabetes M Susan Walker, PhD, RN, CDE, 1 Stephanie J Fonda, PhD, 2 Sara Salkind, MA 3 and Robert A Vigersky, MD, COL USA 4 1. Administrative Director; 2. Senior Research Scientist; 3. Research Associate; 4. Director, Diabetes Institute, Walter Reed National Military Medical Center, Bethesda, Maryland, US Abstract Previous research has shown that realtime continuous glucose monitoring (RT-CGM) is a useful clinical and lifestyle aid for people with type 1 diabetes. However, its usefulness and efficacy for people with type 2 diabetes is less known and potentially controversial, given the continuing controversy over the efficacy of self-monitoring of blood glucose (SMBG) in this cohort. This article reviews the extant literature on RT-CGM for people with type 2 diabetes, and enumerates several of the advantages and disadvantages of this technology from the perspective of providers and patients. Even patients with type 2 diabetes who are not using insulin and/or are relatively well controlled on oral medications have been shown to spend a significant amount of time each day in hyperglycemia. Additional tools beyond SMBG are necessary to enable providers and patients to clearly grasp and manage the frequency and amplitude of glucose excursions in people with type 2 diabetes who are not on insulin. While SMBG is useful for measuring blood glucose levels, patients do not regularly check and SMBG does not enable many to adequately manage blood glucose levels or capture marked and sustained hyperglycemic excursions. RT-CGM systems, valuable diabetes management tools for people with type 1 diabetes or insulin-treated type 2 diabetes, have recently been used in type 2 diabetes patients. The extant studies, although few, have demonstrated that the use of RT-CGM has empowered people with type 2 diabetes to improve their glycemic control by making and sustaining healthy lifestyle choices. Keywords Type 2 diabetes, realtime continuous glucose monitoring systems, advantages and disadvantages Disclosure: The authors’ study evaluating the effect of realtime continuous glucose monitoring on glycemic control in patients with type 2 diabetes was funded by DexCom, Inc. Acknowledgment: The opinions expressed in this paper reflect the personal views of the authors and not the official views of the US Army or the Department of Defense. Received: June 11, 2012 Accepted: June 28, 2012 Citation: US Endocrinology, 2012;8(1):22–6 Correspondence: M Susan Walker, PhD, RN, CDE, Diabetes Institute, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Bethesda, MD 20889-5600, US. E: Susan.Walker@med.navy.mil Realtime continuous glucose monitoring (RT-CGM), which provides a glucose reading and trend every five minutes for up to seven days, is a valuable diabetes management tool for people with type 1 diabetes who, in their quest for tight glycemic control, are particularly vulnerable to severe and potentially life-threatening hypoglycemia. The value of RT-CGM for people with type 2 diabetes is less well recognized, particularly for those who are non-insulin treated. This paper reviews the still nascent literature documenting the efficacy of RT-CGM in people with type 2 diabetes and then addresses the advantages and disadvantages of its use from the perspectives of the healthcare provider and the patient. Previous Studies Documenting Efficacy of Realtime Continuous Glucose Monitoring in People with Type 2 Diabetes The few studies that have examined the clinical efficacy of RT-CGM in people with type 2 diabetes are shown in Table 1. These studies show that RT-CGM may be useful in modifying lifestyle habits and choices and can exert a positive effect for as long as a year beyond the intervention. 22 Using an RT-CGM system as a ‘motivational device’, Yoo et al. conducted a prospective, open-label, randomized controlled trial (RCT) of RT-CGM compared with self-monitoring of blood glucose (SMBG) in 65 adult patients with poorly controlled type 2 diabetes (8.0 % ≤ glycated hemoglobin [HbA 1c ] ≤10 %) over a three-month period. 1 The intervention group used the RT-CGM device for three days each month for three months and the control group continued SMBG at least four times a week for three months. Compared with the SMBG group, the RT-CGM group demonstrated a more significant reduction in HbA 1c (-1.1 % versus -0.4 %), a larger increase in the exercise time per week (+158 minutes versus +43 minutes), and a more pronounced trend toward a decrease in body weight (-2.2 kg versus -1.4 kg). The researchers also measured the mean amplitude of glucose excursion (MAGE) with each RT-CGM application; there was a statistically significant decrease in MAGE between Month 1 and Months 2 and 3. Vigersky et al. conducted a prospective, 52-week, two-arm RCT comparing RT-CGM (n=50) versus SMBG (n=50) in people with type 2 © TOUCH BRIEFINGS 2012