Continuous Glucose Monitoring vs Fingerstick Monitoring for Hemoglobin A1c Control in Veterans

Abstract

BACKGROUND: Patients with diabetes have traditionally been required to use fingerstick testing to self-monitor their glucose levels. However, continuous glucose monitors (CGMs) collect glucose readings throughout the day and display daily trends, which allow clinicians to individualize treatment to achieve hemoglobin A(1c) (HbA(1c)) goals and simplify medication regimens. While studies have shown that CGMs improve HbA(1c) levels compared to fingerstick testing, this research has focused on type 1 diabetes and excluded veterans and patients on insulin therapy. METHODS: This retrospective chart review used a crossover, self-controlled design conducted at the Veterans Affairs Sioux Falls Health Care System. Veterans with an active CGM prescription were included. The primary endpoint compared the change in HbA(1c) before and after initiation of a CGM. RESULTS: The mean baseline HbA(1c) for the 150 veterans included in this study was 8.6%. The change in HbA(1c) before CGM use was 0.003 and change in HbA(1c) after CGM use was -0.971. The primary endpoint of difference in HbA(1c) associated with CGM use was -0.969 (P = .0001). The overall mean change in total daily doses of insulin was -22 units. Subgroup analysis of change in HbA(1c) after CGM use by prescriber type was -0.97 for endocrinology, -0.7 for pharmacy, and -1.23 for primary care practitioners. The overall average HbA(1c) post-CGM use was similar across all prescriber types at 7.64%. CONCLUSIONS: This study found veterans with type 2 diabetes and on insulin therapy demonstrated a significant reduction in HbA(1c) with CGM use compared with their baseline fingerstick monitoring. Use of a CGM may be beneficial in patients who require a reduction in HbA(1c) by allowing more precise adjustments to medications to optimize therapy.