What health improvements go beyond the standard HbA1c test?
CGM reveals problems that a simple HbA1c number misses, especially day-to-day glucose swings and hidden low blood sugar (hypoglycemia). In a 2024 study of 283 adults with type 2 diabetes, two different treatments lowered HbA1c equally well, but CGM data showed that one treatment gave patients 34% more time in the healthy glucose range and cut nighttime hypoglycemia by over 75% [2]. That means fewer dangerous lows and more stable glucose—benefits HbA1c alone cannot show.
CGM also predicts long-term kidney damage better than standard tests. A 2024 study of 245 people with type 2 diabetes found that CGM-derived "time in range" was independently linked to early kidney injury markers (like uNAG/Cr), even before albumin appeared in urine [8]. This suggests CGM can catch kidney risk years earlier than routine urine tests.
And the benefits extend to quality of life. In a survey of nearly 500 adults with diabetes, over 70% said reviewing their CGM weekly summary reports helped reduce diabetes distress and improved their confidence in avoiding low blood sugar [4]. These are real-world improvements in how people feel and function, not just lab numbers.
Who benefits most—and what are the catches?
The biggest gains from CGM appear in people who use it consistently and actively engage with the data. In a pediatric trial of 144 children starting insulin pumps, those who started CGM at the same time as the pump wore it 62 more hours per month six months later, and every extra 100 hours of wear per month was linked to a 0.39% lower HbA1c [5]. But if someone just wears the sensor and ignores the reports, the benefit shrinks—the same survey found that doing nothing with the CGM report was a negative predictor of outcomes [4].
Access is a major barrier. A 2022 population study of 1,209 children with type 1 diabetes in New Zealand found that Pacific Islander children were 38% less likely to use CGM than Māori children, and kids in the poorest neighborhoods had 31% lower use than the wealthiest [3]. Yet when they did use CGM, Māori children saw the biggest HbA1c drops (15.3 mmol/mol lower), meaning unequal access directly worsens health disparities.
Even with good access, you need enough data. A 2025 analysis of 336 real-world CGM users found that to get reliable results, you need at least 14 days of wear (with >45% use) for most metrics, but detecting dangerous low blood sugar requires 28–35 days [9]. Short-term wear can miss the most critical events.
Does CGM prevent long-term complications and save money?
Yes, the evidence points to fewer complications and cost savings over a lifetime. A 2025 Finnish study modeled 50-year outcomes for 336 people with type 1 diabetes and found that automated insulin delivery (which relies on CGM) gave 2.3 more quality-adjusted life-years (QALYs) compared to standard pump therapy with CGM, mainly by delaying diabetes complications like kidney failure and eye disease [6]. The extra cost was about €11,184 per QALY gained—well under typical willingness-to-pay thresholds, meaning it's considered good value for money.
CGM also reduces severe hypoglycemia, which is both dangerous and expensive. In a randomized trial of 156 adults with type 1 diabetes, those using CGM spent 43 fewer minutes per day in hypoglycemia and had zero severe hypoglycemic events (versus two in the fingerstick group) [1]. Avoiding hospital visits for severe lows saves money and lives.
A 2025 review of multiple studies concluded that despite higher upfront costs, CGM prevents enough hospitalizations and complications to reduce overall healthcare spending [7]. The key is that these long-term benefits depend on consistent use—the same review notes that high satisfaction rates and long-term adherence make device issues manageable with proper training.
About These Sources
This answer is built on 9 peer-reviewed studies — published from 2022 to 2025, 5 from 2024 or later, 4 in Q1 journals, collectively cited 228 times — selected as the most relevant from 12 studies that passed quality screening, drawn from 61 papers retrieved from a database of over 500 million.
Sources used in this answer
Intermittently Scanned Continuous Glucose Monitoring for Type 1 Diabetes
In a randomized controlled trial of 156 adults with type 1 diabetes, intermittently scanned CGM with optional alarms lowered HbA1c by 0.5 percentage points more than fingerstick testing and reduced time in hypoglycemia by 43 minutes per day.
Continuous Glucose Monitoring Profiles and Health Outcomes After Dapagliflozin Plus Saxagliptin vs Insulin Glargine.
In a 24-week substudy of 283 adults with type 2 diabetes, CGM revealed that dapagliflozin plus saxagliptin gave 34% more time in range and 75% less nocturnal hypoglycemia than insulin glargine, even though HbA1c reductions were identical.
Inequity in access to continuous glucose monitoring and health outcomes in paediatric diabetes, a case for national continuous glucose monitoring funding: a cross-sectional population study of children with type 1 diabetes in New Zealand
In a cross-sectional population study of 1,209 children with type 1 diabetes in New Zealand, CGM use was 38% lower in Pacific Islander children and 31% lower in the poorest neighborhoods, yet Māori children who used CGM saw the largest HbA1c drops (15.3 mmol/mol).
The Role of Retrospective Data Review in the Personal Use of Real-Time Continuous Glucose Monitoring: Perceived Impact on Quality of Life and Health Outcomes
In a survey of 498 adults with diabetes, over 70% reported that reviewing weekly CGM summary reports reduced diabetes distress and improved hypoglycemia confidence, but doing nothing with the report was a negative predictor of outcomes.
Timing of CGM initiation in pediatric diabetes: The CGM TIME Trial.
In a 5-site randomized trial of 144 children starting insulin pumps, those who started CGM simultaneously wore it 62 more hours per month after 6 months, and every 100 hours of wear per month was associated with a 0.39% lower HbA1c.
Long-term health economic evaluation of automated insulin delivery system compared with continuous subcutaneous insulin infusion pumps and CGM in a real-world setting in Finnish paediatric and adult individuals with type 1 diabetes.
In a 50-year cost-effectiveness model using real-world data from 336 Finnish individuals with type 1 diabetes, automated insulin delivery (CGM-based) provided 2.3 more quality-adjusted life-years and was cost-effective at €11,184 per QALY gained.
Advances in Continuous Glucose Monitoring: Clinical Applications
A 2025 review of CGM clinical applications reports consistent HbA1c reductions of 0.25%–3.0% and time-in-range improvements of 15%–34%, and concludes that despite high initial costs, CGM reduces overall healthcare spending by preventing complications and hospitalizations.
Association between continuous glucose monitoring-derived glycemic control indices and urinary biomarkers of diabetic kidney disease: Hyogo Diabetes Hypoglycemia Cognition Complications study.
In a cross-sectional study of 245 adults with type 2 diabetes, CGM-derived time in range was independently linked to early kidney injury markers (uNAG/Cr and uAlb/Cr), even before albumin appeared in urine, suggesting CGM can detect kidney risk earlier.
Minimum Sampling Duration for Continuous Glucose Monitoring Metrics to Achieve Representative Glycemic Outcomes in Suboptimal Continuous Glucose Monitor Use.
In an analysis of 90-day CGM data from 336 real-life users with type 1 diabetes, at least 14 days of wear (with >45% use) was needed for most metrics, but detecting hypoglycemia required 28–35 days.