Adults with poorly controlled type 2 diabetes who used continuous glucose monitors experienced sustained blood sugar improvements and reduced urine protein levels over a three-year study published in JAMA Network Open, though kidney filtration rates showed no significant change.
People managing type 2 diabetes often rely on periodic HbA1c tests to track their condition, but managing daily blood sugar fluctuations without continuous feedback can leave patients guessing about how food, activity, and medication interact. A landmark observational study evaluated electronic health records from Kaiser Permanente Northern California to see what happens when high-risk patients use real-time continuous glucose monitoring over an extended period. Researchers followed participants for up to 36 months to measure long-term glycemic control and markers of kidney health.
Analysis Examines Diabetes Registry Data from Thousands of Participants
The investigation drew from the Kaiser Permanente Northern California Diabetes Registry, analyzing 25,648 participant assignments across two groups. Because some patients contributed observations to both groups at different times, the analysis covered 25,371 unique individuals. Participants averaged 61.5 years of age, and 54.7% were men. At baseline, the sample showed severe glycemic challenges, with a mean HbA1c of 9.5%. Nearly all participants—96.9%—had an HbA1c greater than 8% during the preceding 12 months, and 5.5% had visited an emergency department or suffered hospitalization for dangerously low blood sugar in the previous 36 months.
Researchers compared 2,771 real-time continuous glucose monitoring initiators with 22,877 temporally matched controls using statistical weighting to account for baseline differences. While standard eligibility criteria typically restrict monitors to insulin users or patients prone to severe hypoglycemia, the study captured a complex patient population. Investigators utilized electronic medical records to track HbA1c, estimated glomerular filtration rate, and the urine albumin-creatinine ratio over three years.
Patients Using Monitors Achieve Sustained Blood Sugar Reduction
After one year, patients using the monitors achieved a significant reduction in HbA1c compared with controls, and that improvement remained largely stable throughout the three-year study period. By the end of the 36 months, mean HbA1c stayed lower in the monitor group than in controls at 7.83% versus 8.58%, maintaining a difference of 0.75 percentage points.
Endocrinologists note that while standard medications help lower glucose, patients taking them without sensor technology operate with minimal insight into rapid blood sugar shifts. Real-time devices provide immediate feedback that assists users in making daily dietary, physical activity, and dosing choices.
Urine Protein Reductions Versus Kidney Filtration Measures
Beyond glycemic tracking, the study examined whether sustained monitoring offered protective effects against chronic kidney disease, a condition that eventually develops in roughly 30% of people with type 2 diabetes. While baseline urine albumin-creatinine ratio measurements showed no significant differences between groups initially or at one and two years, a clear shift emerged by the third year.
Sustained monitor use was associated with a lower mean urine albumin-creatinine ratio at 36 months, registering at 153 mg/g in the monitor group compared with 278 mg/g in controls—a difference of about 125 mg/g. This divergence points toward a later reduction in albuminuria, which serves as an early marker for preserved kidney health and reduced organ decline.
Despite the favorable drop in urine protein, the trial found no evidence that the technology preserved kidney filtration function. Estimated glomerular filtration rates were lower at baseline in the monitor group and remained significantly lower during the first two years, with the difference losing statistical significance by year three. Substantial patient crossover and discontinuation—including 44.3% of monitor initiators who were censored after stopping device use—created smaller sample sizes by the final assessment, introducing additional uncertainty into the long-term renal findings.
Researchers Suggest Broader Applications for Continuous Glucose Monitors
With funding support from Dexcom Inc., The Permanente Medical Group, the Kaiser Foundation Research Institute, the National Institute on Aging, and the National Institute of Diabetes and Digestive and Kidney Diseases, the findings point toward broader applications for continuous glucose monitors outside of routine insulin management.
Researchers suggest that high-risk individuals, particularly those exhibiting signs of cardiovascular-kidney-metabolic syndrome or established diabetic kidney disease, might experience clinical advantages from wearing sensors even if they do not require insulin. Investigators emphasize that randomized clinical trials with extended follow-up windows remain necessary to confirm whether sustained monitor use can directly prevent the progression of kidney disease or lower cardiovascular complication risks.