Background: Color affects emotions, feelings, and behaviors. We hypothesized that color used in self-monitoring of blood glucose (SMBG) is helpful for patients to recognize and act on their glucose levels to improve glycemic control. Here, two color-indication methods, color record (CR) and color display (CD), were independently compared for their effects on glycemic control in less frequently insulin-treated type 2 diabetes.
Subjects and methods: One hundred twenty outpatients were randomly allocated to four groups with 2×2 factorial design: CR or non-CR and CD or non-CD. Blood glucose levels were recorded in red or blue pencil in the CR arm, and a red or blue indicator light on the SMBG meter was lit in the CD arm, under hyperglycemia or hypoglycemia, respectively. The primary end point was difference in glycated hemoglobin (HbA1c) reduction in 24 weeks. Secondary end points were self-management performance change and psychological state change.
Results: HbA1c levels at 24 weeks were significantly decreased in the CR arm by -0.28% but were increased by 0.03% in the non-CR arm (P=0.044). In addition, diet and exercise scores were significantly improved in the CR arm compared with the non-CR arm. The exercise score showed significant improvement in the CD arm compared with the non-CD arm but without a significant difference in HbA1c reduction. Changes in psychological states were not altered between the arms.
Conclusions: CR has a favorable effect on self-management performance without any influence on psychological stress, resulting in improved glycemic control in type 2 diabetes patients using less frequent insulin injection. Thus, active but not passive usage of color-indication methods by patients is important in successful SMBG.