Use of a real time continuous glucose monitoring system as a motivational device for poorly controlled type 2 diabetes

Abstract

Objective

The use of a real time continuous glucose monitoring system (RT-CGM) was studied as a behavior modification tool and the effectiveness of a RT-CGM in glucose control for patients with type 2 diabetes was determined.

Methods

We conducted a prospective, open-label, randomized, controlled clinical trial in 65 patients with poorly controlled type 2 diabetes (8.0 ≤ HbA1c ≤ 10%) over a 3-month period. The intervention group was monitored monthly with a RT-CGM (three days at a time for 3 months) and the control group continued self-monitoring blood glucose (SMBG) at least four times a week for 3 months.

Results

The HbA1c of the RT-CGM group was significantly reduced after 12 weeks compared with the SMBG group (9.1 ± 1.0% to 8.0 ± 1.2% vs. 8.7 ± 0.7% to 8.3 ± 1.1%, respectively; P = 0.004). In the RT-CGM group, there was a significant reduction in total daily calorie intake, weight, body mass index (BMI), and postprandial glucose level, and a significant increase in total exercise time per week after 3 months.

Conclusions

We demonstrated that the RT-CGM was useful in modifying a patient's diet and exercise habits and could induce better glycemic control than SMBG for patients with type 2 diabetes.

Introduction

Compliance, disease awareness, and empowerment of the patient play important roles in the management of diabetes. Self-management education for diabetes has been an integral part of high quality primary care [1]. Immediate feedback on the effects of diet and exercise that self-monitoring blood glucose (SMBG) provides can enhance empowerment of the patient [2]. SMBG might improve adherence to pharmacologic treatment and motivate patients to make appropriate changes of lifestyle [3]. Guerci et al. [4] demonstrated that SMBG for 6 months was statistically associated with a better quality of metabolic control in patients with type 2 diabetes who were not receiving insulin therapy than usual traditional recommendations alone. However, a recent study of longer duration suggested that SMBG monitoring in patients with non-insulin treated type 2 diabetes did not improve glycemic control [5]. Because of many factors, such as pain and inconvenience, many diabetic patients do not accept frequent finger-sticks for SMBG [6]. In addition, SMBG gives a single instant reading without any information on glucose trends and thus may miss significant glucose fluctuations [7]. Therefore, a new glucose monitoring method that can continuously reflect glucose trends and effectively modulate glycemic control is needed.

The Guardian continuous glucose monitoring system (Guardian RT; Medtronic MiniMed, Northridge, CA, USA) is a real time continuous glucose-sensing and display device that alerts patients to predetermine thresholds of impending hypo- and hyper-glycemia, allowing immediate corrective action that may preempt severe consequences [8]. Since 2004, there have been several studies about real time continuous glucose monitoring systems (RT-CGM). First, Bode et al. [8] reported the accuracy and the effectiveness of the Guardian RT for type 1 diabetes and Deiss et al. [9] demonstrated a clinically meaningful reduction of HbA1c in type 1 diabetic patients in a randomized, controlled trial using a RT-CGM. However, there have been no studies regarding the effectiveness of a RT-CGM as a behavior modification tool for type 2 diabetes and measurement of the changes in diet pattern and physical activity following the application of a RT-CGM.

The purpose of this study was to determine whether a RT-CGM in the home setting is useful for poorly controlled type 2 diabetes with a view to modify a patient's diet and exercise habits and improve disease self-control efforts, thereby inducing better glycemic control compared with SMBG.