Continuous Glucose Monitoring in Relation to Long-Term Glycemic Control and Kidney Outcomes

By
Andrew J. Karter
Melissa M. Parker
Holly Finertie
Joshua R. Nugent
Lisa K. Gilliam
Ajit Mahapatra
October 7, 2026

Jama Network Open

Overview

This observational comparative-effectiveness study emulated a target trial to examine sustained real-time continuous glucose monitoring (rtCGM) use and changes in HbA1c, urinary albumin-creatinine ratio, and estimated glomerular filtration rate among high-risk adults with type 2 diabetes. The supplied article excerpt describes the study rationale, eligibility, and design but does not provide outcome estimates or results; therefore, effects on glycemic control and kidney outcomes cannot be summarized from the available material.

Background

CGM measures interstitial-fluid glucose using subcutaneous sensors; rtCGM provides immediate feedback, whereas intermittently scanned CGM requires users to scan the device. Prior randomized trials and observational studies cited in the article reported improved glycemic control after CGM initiation, but their relatively short follow-up left uncertainty about sustained effects. The article also notes that existing trials had not established whether CGM preserves kidney function or reduces kidney damage. To address these evidence gaps, investigators used electronic health records and a target trial emulation approach intended to estimate effects in usual care while addressing limitations such as time-varying confounding.

Data Highlights

Study feature	Details reported in the supplied excerpt
Sampling frame	573,663 patients with type 2 diabetes in the Kaiser Permanente Northern California diabetes registry on January 1, 2015, with no prior CGM exposure
Exposure period	January 1, 2015, through June 30, 2023
Eligibility	Adults aged 19 years or older with HbA1c greater than 8% in the preceding 12 months or an emergency department visit or inpatient admission for hypoglycemia in the preceding 36 months
Exposure definition	rtCGM initiation identified through durable medical equipment claims; analysis limited to rtCGM
Follow-up	36 months from baseline, defined as the first rtCGM claim
Outcomes	Changes in HbA1c, urinary albumin-creatinine ratio, and estimated glomerular filtration rate

Key Findings

The study was designed as an observational comparative-effectiveness analysis emulating a target trial of initiating and maintaining rtCGM.
The sampling frame included 573,663 registry patients with type 2 diabetes and no CGM exposure before January 1, 2015; the excerpt does not state the final analytic sample size.
Eligibility was restricted to high-risk adults aged 19 years or older, defined by HbA1c greater than 8% in the prior 12 months or a hypoglycemia-related emergency department visit or inpatient admission in the prior 36 months.
rtCGM exposure was identified from durable medical equipment claims, and follow-up ended 36 months after the first rtCGM claim.
Prespecified outcomes were changes in HbA1c, urinary albumin-creatinine ratio, and estimated glomerular filtration rate; the supplied excerpt contains no outcome results.
The related article context reports that a randomized crossover trial in patients with insulin-treated type 2 diabetes receiving maintenance hemodialysis found no significant reduction in time below range with rtCGM, while secondary measures of time in range, time above range, and mean glucose improved.

Clinical Implications

The supplied excerpt establishes the study population, exposure definition, follow-up, and kidney and glycemic outcomes, but it does not report results that would support conclusions about long-term effects. The related dialysis trial context describes changes in glucose metrics, not evidence that CGM preserves kidney function or reduces kidney damage.

Conclusion

The article describes a target trial emulation designed to assess long-term glycemic and kidney outcomes associated with rtCGM initiation and maintenance in high-risk adults with type 2 diabetes. Because the supplied excerpt omits the study’s results, its findings on HbA1c, albuminuria, and eGFR remain unspecified here.