Continuous Glucose Monitoring Linked to Long-Term Glycemic Benefits
A three-year observational study published in JAMA Network Open suggests that sustained use of real-time continuous glucose monitoring (rtCGM) is associated with durable improvements in glycemic control for high-risk adults with type 2 diabetes. While the study found a potential reduction in albuminuria, a marker of kidney health, by the end of the three-year follow-up, it did not demonstrate that the technology preserves overall kidney filtration function.
Guidelines from the American Diabetes Association and Kidney Disease: Improving Global Outcomes highlight the important role of continuous glucose monitoring technology to assess glycemic management and hypoglycemia risk in patients with diabetes and chronic kidney disease.
Study Design and Glycemic Outcomes
Researchers from Kaiser Permanente Northern California analyzed electronic health records for 25,371 unique individuals with type 2 diabetes. The study compared patients who initiated rtCGM with a matched control group. Participants in the rtCGM group generally presented with more complex clinical profiles at baseline, including longer diabetes duration and higher rates of insulin use. Despite these differences, statistical weighting was used to balance the groups.
Sustained rtCGM use was linked to rapid and persistent improvements in hemoglobin A1c (HbA1c) levels. One year after baseline, the weighted mean HbA1c was 7.83% for rtCGM users compared to 8.93% for the control group. This improvement persisted through the three-year mark, with rtCGM users maintaining a mean HbA1c of 7.83% versus 8.58% in the control group.
Kidney Health Findings and Limitations
Regarding kidney health, the study assessed the urinary albumin-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR). While no significant differences in UACR were observed in the first two years, rtCGM users showed a lower mean UACR at three years, suggesting a potential reduction in albuminuria. However, the study found no evidence that rtCGM use preserved kidney filtration function, as measured by eGFR, over the three-year period.
The researchers noted several limitations, including an observational design and substantial participant attrition, with 44.3% of rtCGM initiators discontinuing the device during follow-up. These factors, along with the possibility of residual confounding, limit the ability to draw definitive causal conclusions. The authors emphasized that while rtCGM may improve blood glucose management and reduce albuminuria, longer-term randomized clinical trials are necessary to confirm whether the technology can effectively delay the progression of diabetic kidney disease.
What long-term CGM results do—and do not—prove
Continuous glucose monitoring records frequent readings and trends, allowing people and clinicians to identify patterns that a periodic finger-prick test may miss. Its benefit depends on the population studied, training, sensor accuracy and how patients act on the information. If a study reports better HbA1c outcomes, the useful details include whether participants used insulin, how the comparison group was managed, follow-up length and whether severe hypoglycaemia also changed. Association across longer follow-up is not automatically proof that the device alone caused better outcomes. Patients should discuss suitability, affordability, calibration needs and the interpretation of unusual readings with a qualified care team; device data should not prompt unsupervised medication changes.