Glucose-monitor study finds lasting blood-sugar gains, with kidney benefits still uncertain

Continuous glucose monitoring was associated with sustained improvements in blood sugar and a later reduction in a marker of kidney damage among high-risk adults with type 2 diabetes, according to research published October 7 in JAMA Network Open. The findings extend the evidence on longer-term monitoring, while leaving its ability to protect kidney function unresolved.

Kaiser Permanente researchers compared 2,771 people who began using real-time monitors with a comparison group who had not started them. Participants had poorly controlled blood sugar or a history of emergency or hospital treatment for dangerously low glucose. Electronic health records allowed researchers to examine outcomes over as long as three years.

The distinction between better glucose management and demonstrated kidney protection matters for healthspan. Diabetes can damage organs over many years, but an encouraging laboratory change does not by itself establish that an intervention prevents disability or extends life.

What the study found

The observational analysis used a target trial emulation: statistical methods designed to approximate a comparison of sustained monitor use against nonuse. Patients were not randomly assigned devices.

At three years, estimated HbA1c was 7.83% in the monitoring group and 8.58% in controls, a difference of 0.75 percentage points. HbA1c reflects average blood glucose over approximately three months.

Urinary albumin-to-creatinine ratio was also lower in the monitoring group at year three, although differences were not significant in the first two years. Estimated glomerular filtration rate, the measure of kidney filtering capacity, showed no benefit at the three-year endpoint.

These outcomes answer different questions. Better glucose control demonstrates a favorable metabolic association; the urine result raises a further possibility that requires confirmation.

Why the kidney measurements differ

The National Institute of Diabetes and Digestive and Kidney Diseases describes albuminuria as excess leakage of a blood protein into urine. Healthy kidneys generally retain that protein. Measuring albumin helps clinicians detect kidney damage and monitor changes over time, and falling levels can indicate a favorable treatment response.

Filtration tests assess another aspect of kidney health: how effectively the organs remove waste from the blood. Clinical assessment uses both blood and urine measurements because they provide complementary information.

That distinction limits the conclusion available here. A lower urine-protein measurement is encouraging, but a claim that monitors prevent kidney failure would require evidence about that outcome. The study’s findings cannot supply that missing step.

Sustained use remains a challenge

Follow-up stopped when participants departed from their assigned analytical strategy. Among monitor initiators, 44.3% were censored because they discontinued use; 18.7% of controls were censored after starting monitoring. Statistical adjustment cannot eliminate uncertainty from unmeasured differences between groups or substantial attrition.

The research also came from one health system. Kaiser Permanente reported funding from Dexcom, alongside institutional and federal support.

Practical constraints matter when interpreting sustained-use findings. NIDDK explains that monitors estimate glucose using a sensor beneath the skin and transmit readings to a receiver or connected device. They can reveal patterns and alert users to high or low readings, but they require ongoing supplies, learning and attention. Cost, insurance coverage and skin irritation can complicate use.

The technology therefore operates within a broader care process: collecting information, understanding it and responding appropriately. For prevention research, the next question is whether sustained access and use translate into fewer serious complications across different care settings. This study strengthens the rationale for investigating that question without resolving it.