Continuous Glucose Monitoring Shows Three-Year Glycemic Benefits in Type 2 Diabetes
Sustained use of real-time continuous glucose monitoring devices is associated with persistent improvements in blood sugar control among high-risk adults with type 2 diabetes, according to a study published in JAMA Network Open. Adults using the sensors experienced lower hemoglobin A1c levels over a three-year period, alongside a late reduction in urinary albumin-creatinine ratio, News-Medical reported. However, the observational study found no evidence that the technology preserved overall kidney filtration function during the same timeframe.
Study Design and Patient Populations at Kaiser Permanente
Researchers conducted an observational comparative effectiveness study using electronic health records from Kaiser Permanente Northern California, evaluating a target trial emulation approach to compare device users against non-initiators. The analysis drew from a sampling frame of 573,663 patients with type 2 diabetes as of January 1, 2015.
The study cohort ultimately comprised 25,648 participant assignments across two primary groups, encompassing 2,771 real-time continuous glucose monitoring initiators and 22,877 controls. Because individuals occasionally contributed observations to both cohorts at different times, the final data set involved 25,371 unique individuals. Participants averaged 61.5 years of age, and 54.7% were men. Baseline clinical characteristics revealed that device initiators presented with more complex profiles, including a longer mean diabetes duration of 17.6 years compared to 12.6 years for controls, and a substantially higher rate of baseline insulin use at 89.1% versus 38.8%.
Glycemic Control and Three-Year Kidney Marker Outcomes
Investigators tracked primary outcomes including hemoglobin A1c, the urinary albumin-creatinine ratio, and the estimated glomerular filtration rate for up to 36 months. Statistical weighting successfully balanced baseline differences between the cohorts. One year after baseline, the weighted mean HbA1c dropped to 7.83% among device initiators compared to 8.93% for controls, marking a difference of 1.10 percentage points. That improvement persisted over time, with a difference of 0.90 percentage points at two years and 0.75 percentage points at three years, where mean levels sat at 7.83% for the monitoring group and 8.58% for controls.
Regarding kidney health markers, researchers identified no statistically significant differences in the urinary albumin-creatinine ratio between groups at baseline or at the one- and two-year marks. By year three, however, sustained device use was associated with a lower mean urinary albumin-creatinine ratio of 153 mg/g compared to 278 mg/g in the control group, representing a difference of approximately 125 mg/g. Despite this later reduction in albuminuria, estimated glomerular filtration rate measurements—which assess how effectively kidneys filter blood—did not show that the devices preserved kidney filtration function over the three-year follow-up period.
Substantial discontinuation and crossover between the study groups limited the long-term follow-up data.