A new study in JAMA Network Open followed adults with poorly controlled type 2 diabetes for up to three years and compared people who started a real-time continuous glucose monitor with people who did not. The sensor users had a lower A1C throughout, and less albumin in their urine at the three-year mark, but their kidney filtration score did not improve. Here is what the study found, what it cannot prove, and which lab results are worth watching if you use a continuous glucose monitor.
最新研究が明らかにしたこと
The research, published in JAMA Network Open in October 2026 and summarized by News-Medical, used electronic health records from Kaiser Permanente Northern California. The authors compared 2,771 adults who started a real-time continuous glucose monitor (a small sensor worn on the skin that reads glucose every few minutes) with 22,877 comparable adults who did not. All had type 2 diabetes with poor glycemic control, and they were followed for up to 36 months.
A1C was lower at every checkpoint
A1C reflects your average blood sugar over roughly three months. In the study, sensor users had an A1C 1.10 percentage points lower after one year, 0.90 points lower after two years, and 0.75 points lower after three years (7.83% versus 8.58%). The gap narrowed with time, but it never disappeared.
Albuminuria: a later signal
Albuminuria means albumin, a blood protein, is leaking into the urine, which is an early sign of kidney stress. It is measured with the urine albumin-to-creatinine ratio. There was no difference between the groups at baseline, at one year, or at two years. At three years, the ratio was about 153 mg/g in sensor users versus 278 mg/g in the comparison group, but that analysis included only 331 sensor users and 3,890 comparison participants.
eGFR showed no clear benefit
The estimated glomerular filtration rate, or eGFR, estimates how well your kidneys filter blood. Sensor users started with a lower eGFR, and the difference was no longer statistically significant at three years. The authors found no evidence that the sensors preserved kidney filtration.
| Lab marker | 分かること | What the study reported |
|---|---|---|
| A1C | 約3か月間の平均血糖値 | Lower in sensor users at one, two and three years |
| 尿中アルブミン・クレアチニン比 | Protein leaking into the urine, an early kidney signal | No difference until year three, then lower in sensor users (small subgroup) |
| eGFR | How well the kidneys filter blood | No evidence that filtration was preserved |
Why this does not prove glucose monitors protect the kidneys
The authors themselves state that the study does not show that a sensor prevents kidney disease from progressing. Several limits matter for anyone reading the headline.
- It was an observational study, so people who choose a sensor may differ from those who do not in motivation, access to care, or support, even after statistical balancing.
- Many participants dropped out of their group: 44.3% of sensor users stopped using the device and were censored, and 18.7% of comparison participants started a sensor.
- The three-year kidney analysis was far smaller than the full group, which makes the albuminuria result less certain.
- Sustained use was inferred from supply claims, not measured directly, and the findings apply only to real-time sensors, not to scanned systems.
- Dexcom was among the funders, although the authors report that funders had no role in design, analysis or publication decisions.
最新の科学的進歩
According to PubMed, two other 2026 papers help put this study in context. A small retrospective study in people newly diagnosed with type 2 diabetes found that bigger blood sugar spikes after meals, as recorded by a two-week sensor, were linked to a greater rise in urinary albumin over six months, even after accounting for A1C and fasting glucose. In plain terms, A1C can look similar in two people whose after-meal spikes are very different, and the spikes may carry extra information about the kidneys. The authors call for outside validation before this is used in practice.
A systematic review of observational studies also found that spending more of the day in the target glucose range, called time in range, was linked with lower risks of death and of several complications, including eye and nerve damage. For albuminuria, however, the link did not reach statistical significance in the main analysis. What this changes for you: sensor data may become a useful complement to A1C, but it has not replaced your kidney labs.
What this means for your lab results
Read A1C and sensor data together
A1C and a sensor measure different things. A1C is a three-month average, while a sensor shows daily patterns, including spikes and overnight lows. If your numbers do not match your sensor readings, bring both to your appointment. To see how results are graded, read our guide to HbA1c normal range and target levels.
Keep your kidney labs on the calendar
Early diabetic kidney disease often causes no symptoms, so it is found through testing. Mayo Clinic advises people with diabetes to see their care team at least yearly, or as directed, for kidney function tests. A urine test and a blood test together give the clearest picture. You can learn how the urine marker works in our explanation of the microalbuminuria urine test, and how filtration is estimated in our overview of the eGFR kidney filtration rate.
Know the limits of the device
The National Institute of Diabetes and Digestive and Kidney Diseases explains that sensor readings are estimates and may need fingerstick confirmation. Sensors also need replacing every 7 to 14 days and cost more than a standard meter. Whether one suits you is a decision for you and your doctor. For the bigger picture, see our complete guide to diabetes causes, symptoms and treatments.
医師に相談するタイミング
- Your A1C stays above the target you and your doctor agreed on despite treatment.
- Your latest urine albumin result or eGFR has changed from the previous one.
- You notice foamy urine, swelling in the feet, ankles or hands, or unusual tiredness.
- You are considering a glucose sensor and want to know whether it fits your treatment and budget.
Never change your medication or stop a treatment on your own because of a news report.
用語集
- HbA1c: a blood test showing your average blood sugar over about three months.
- アルブミン尿: the presence of albumin, a blood protein, in the urine, often an early sign of kidney damage.
- 持続血糖モニター（CGM）: a wearable sensor that estimates glucose in the fluid under the skin every few minutes.
- eGFR: an estimate of how well your kidneys filter blood, calculated from a blood creatinine result.
- Time in range: the share of the day your glucose stays within a target range.
よくある質問
Does a continuous glucose monitor protect my kidneys?
This study cannot say. It found lower A1C and, later, lower urine albumin in sensor users, but not better kidney filtration, and it was observational.
Can a glucose monitor replace the A1C test?
No. The two tests measure different things and are usually used together.
Which kidney tests do people with diabetes need?
Typically a blood test that gives the eGFR and a urine test for albumin. Your doctor decides how often, and Mayo Clinic suggests at least yearly. See our guide to the kidney function panel for what each result means.
Who was included in the study?
Adults with type 2 diabetes and poor glycemic control who had never used a sensor, with an average age of about 61.
参考文献
- News-Medical, October 12, 2026: summary of Karter et al., JAMA Network Open, 2026
- Yu T. Postprandial hyperglycemic area from continuous glucose monitoring and change in urinary albumin-to-creatinine ratio. Frontiers in Endocrinology, 2026
- Qu F et al. Time in Range and Adverse Outcomes in Type 2 Diabetes: A Quantitative Synthesis. Journal of Clinical Medicine, 2026
- NIDDK (NIH): Continuous Glucose Monitoring
- Mayo Clinic: Diabetic nephropathy (kidney disease)
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