When evidence-based practice takes precedence, authoritative guidelines must keep up! Diabetes monitoring is undergoing a comprehensive upgrade
In 2023, the Standards of Care in Diabetes - 2023 developed by the American Diabetes Association (ADA) included continuous glucose monitoring (CGM) in the core decision-making loop for diabetes management for the first time. Just two years later, the latest edition of the ADA's Standards of Care in Diabetes -2025 took an even more landmark step: CGM can be used for all patients with type 1 diabetes mellitus(T1DM) and type 2 diabetes mellitus(T2DM), whether or not they are receiving insulin therapy.
Figure. Upgrade of CGM recommendations in ADA's Standards of Care in Diabetes
This marks a comprehensive upgrade in the concept of diabetes management from "static" to "dynamic". The reason why such a crucial step can be taken is not only due to the update of concepts, but also the result of the joint promotion of a large number of evidence-based studies...
T1DM : CGM Improves Key Outcomes
In patients with T1DM, early clinical studies on CGM mainly focused on adults and adolescents using insulin pumps or multiple daily insulin injections (MDI) [1-6]. The results generally showed that CGM can significantly improve blood glucose control and reduce the level of glycated hemoglobin (HbA1c). Moreover, the benefits brought by CGM can be observed in adults of different age groups, including elderly patients [7-9].
For children with T1DM, the loss of islet function and rapid changes in insulin requirements make them more prone to hypoglycemia. Moreover, children's diet and exercise are often unpredictable, and they cannot accurately describe their physical discomfort, so traditional fingertip blood glucose testing often fails to timely reflect real fluctuations. The real-time monitoring function of CGM just makes up for this deficiency.Studies have found that CGM can significantly reduce hypoglycemic events in children with T1DM, especially those occurring at night[10-12]. This not only helps ensure the safety of children with T1DM, but also allows parents to let go of some of their worries about "staying up at night". Through mobile phones or smart devices, parents can remotely check the child's blood glucose trends at any time and receive abnormal reminders, avoiding missing critical moments.
For adolescents and young adults with T1DM, due to their fast-paced and irregular lifestyles, coupled with factors such as academic studies, social interactions, and emotional fluctuations, blood glucose control is more challenging. The research evidence on CGM is also clear: CGM can improve HbA1c, increase the time in range (TIR), and reduce severe/asymptomatic hypoglycemic events [4, 13].
| Outcome Indicators | CGM (N=74) | BGM (N=79) | 26-week CGM (N=71) | 26-week CGM (N=71) | Between-Group Variability (95% CI) | P-Value |
| Main Outcome Indicators | ||||||
| HbA1c,Standard Deviation(SD),% | 8.9(1.0) | 8.9(1.0) | 8.5(1.2) | 8.9(1.2) | -0.37 (-0.66-0.08) | 0.01 |
| Change from baseline of HbA1c, mean (SD),% | / | / | -0.4(1.0) | 0.1(0.8) | / | / |
| Secondary Outcome Indicators | ||||||
| HbA1c＜7.0%，case(%) | 1(1) | 2(3) | 6(8) | 4(6) | 4(-4-11) | 0.30 |
| HbA1c＜7.5%，case(%) | 3(4) | 7(9) | 13(18) | 8(11) | 9(-1-18) | 0.11 |
| Achieve HbA1c target value (Under 19 years old ＜7.5%, Over 19 years old <7.0%) , cases(%) | 2(3) | 6(8) | 9(13) | 7(10) | 4(-6-12) | 0.42 |
| Relative reduction in HbA1c ≥10%, cases (%) | / | / | 20(28) | 6(8) | 19(8-32) | 0.05 |
| Absolute decrease in HbA1c ≥0.5%, cases (%) | / | / | 31(44) | 15(21) | 23(7-37) | 0.05 |
| Absolute decrease in HbA1c ≥1.0%, cases (%) | / | / | 18(25) | 4(6) | 19(8-31) | 0.03 |
| Absolute decrease in HbA1c ≥0.5% or HbA1c ≤ 7.0% , cases (%) | / | / | 19(27) | 8(11) | 15(3-28) | 0.02 |
| Baseline | Follow-up Period (Combine 13-week and 26-week data ) | Between-Group Variability (95% CI) | P-Value | |||
| Secondary CGM Indicators | CGM (N=73) | BGM (N=79) | CGM (N=68) | BGM (N=72) | ||
| CGM monitoring duration,Median (IQR) | 302(269-324) | 311(268-378) | 376(262-475) | 426(371-477) | ||
| TIR(70-180mg/dL) ,Mean (SD), % | 37(13) | 36(12) | 43(15) | 35(12) | 6.9(3.1-10.7) | ＜0.001 |
| MBG,Mean (SD), mg/dL | 209(36) | 212(36) | 199(36) | 217(35) | -14.3(-23.6--5.1) | 0.003 |
| CV,Mean (SD), % | 42(7) | 42(7) | 39(6) | 42(7) | -2.2(-3.9--0.5) | 0.01 |
| Hyperglycemia | ||||||
| Proportion of time with blood glucose>180mg/dL, Mean (SD),% | 58(15) | 59(15) | 54(18) | 61(14) | -5.8(-10.0--1.7) | 0.007 |
| Proportion of time with blood glucose>250mg/dL, Mean (SD),% | 32(15) | 34(15) | 26(15) | 35(14) | -7.9(-12.3--3.4) | ＜0.001 |
| Proportion of time with blood glucose>300mg/dL, Median,(IQR),% | 15(9-26) | 17(11-28) | 11(5-19) | 20(12-26) | -5.1(-8.2--2.3) | ＜0.001 |
| Hypoglycemia | ||||||
| Percentage of time with bloodglucose <70 mg/dL, InterquartileRange (QR), % | 3.2(1.3-7.7) | 3.7(1.7-6.7) | 2.2(1.0-5.0) | 3.2(1.9-6.2) | -0.7(-1.5--0.1) | 0.02 |
| Percentage of time with bloodglucose < 54 mg/dL, InterquartileRange (IQR), % | 1.0(0.4-3.2) | 1.3(0.3-3.0) | 0.7(0.2-1.4) | 1.3(0.5-2.5) | -0.4(-0.7--0.1) | 0.002 |
| Weeky incidence rate of hypoglycemic events | 1.5(0.6-3.3) | 1.7(0.6-3.2) | 1.4(0.4-2.6) | 1.7(1.0-3.1) | -0.3(-0.7-0.1) | 0.11 |
Table. Compared with BGM, during the use of CGM, the HbA1c of adult patients with T1DM significantly decreased, and multiple dynamic blood glucose indicators were comprehensively improved, with good safety[13]
As early as 2021, "Chinese Guidelines for the Diagnosis and Treatment of T1DM" [14], clearly proposed that CGM should be used as an important method for blood glucose monitoring. Moreover, patients with T1DM who have poor islet function and large blood glucose fluctuations are more likely to benefit from CGM.
The recently released "Chinese Expert Consensus on the Application of Technologies Related to T1DM Management (2025)"[23] clearly recommends that CGM be used as the preferred method for blood glucose monitoring in all patients with T1DM, among which the clinical application of real-time CGM has more advantages.
Overall, CGM has demonstrated significant clinical value in T1DM patients of all age groups and with different treatment methods, ranging from children to elderly patients, and from insulin pumps to multiple insulin injections. This "visible blood glucose dynamics" not only improves the accuracy of blood glucose management but also enhances their sense of control over their own metabolic status. It can be anticipated that with the widespread application of CGM, the refined and individualized management of T1DM will further develop, bringing patients safer and more effective blood glucose control and a better quality of life!
Type 2 Diabetes Mellitus (T2DM): The Evidence-Based Value of CGM is Emerging
Many people may think that CGM is just an "advanced" tool needed only by people with T1DM or those using insulin pumps. But that's not the case! In recent years, more and more studies have shown that CGM also plays a significant role in T2DM management!
Whether for T2DM patients on MDI regimen [15], basal insulin [16-17], or combination therapy [18-19], or even those without insulin therapy [20], the use of CGM can bring significant improvements: a significant reduction in HbA1c and a significant prolongation of TIR. This means that CGM is no longer just a tool for specific populations, but an important weapon throughout the entire process of T2DM management.
Interestingly, when patients stop using CGM, the improvement in blood glucose often "diminishes"—HbA1c rises again, and TIR also shortens [21]. In other words, to truly achieve long-term and stable benefits in blood glucose management, it is best to use CGM continuously!
What is even more encouraging is that real-world data from over 70,000 patients [22] also supports the significant clinical and economic value of CGM for patients with T2DM. The results show that after using CGM for 6–12 months, patients with T2DM not only have better blood glucose control, but also have significantly fewer emergency visits and hospitalizations; HbA1c begins to decrease significantly after about 3 months and can be maintained in the long term. This not only indicates that CGM has clear clinical value, but also reflects its potential in improving the quality of life of patients with T2DM and reducing the medical burden.
![Figure. Changes in all-cause hospitalization (ACH) [Figure 3 (A)], acute diabetes-related hospitalization (ADH) [Figure 3 (B)], and acute diabetes-related emergency room visits (ADER) [Figure 3 (C)] at 6-month and 12-month follow-up periods after using CGM](../uploadfiles/20260908/2026090817030900473.jpg)
Figure. Changes in all-cause hospitalization (ACH) [Figure 3 (A)], acute diabetes-related hospitalization (ADH) [Figure 3 (B)], and acute diabetes-related emergency room visits (ADER) [Figure 3 (C)] at 6-month and 12-month follow-up periods after using CGM
Figure. Improved glucose control associated with continuous glucose monitoring use at 3, 6 and 12 months.
In conclusion, CGM is not only an "exclusive weapon" for T1DM, but alsoplays a key role in the Whole-process management of T2DM. Whether it is the initial diagnosis stage, the oral medication stage, or the stages of using basal insulin, MDI, as well as daily life management, CGM can provide doctors and patients with continuous, dynamic, and quantifiable blood glucose information, making treatment more precise, risks more controllable, and decisions more evidence-based.
The clinical value of "beyond HbA1c" provided by CGM
As one of the most important indicators for long-term blood glucose control, HbA1c can intuitively reflect the average blood glucose level over the past 2 to 3 months, but it is a relatively static and lagging indicator. In contrast, the multi-dimensional indicators provided by CGM, such as TIR, Time Above Range (TAR), Time Below Range (TBR), and Coefficient of Variation (CV), can more sensitively reflect short-term risks and the quality of daily management compared with the single HbA1c indicator, facilitating refined adjustments to treatment.
Studies have shown that CGM indicators [mean glucose (MG), TAR, TIR] are correlated with HbA1c, among which MG has the highest correlation with TAR. It can be used as a sensitive and reliable indicator for evaluating therapeutic efficacy, which is better than relying solely on HbA1c [24].
TIR is also closely associated with the risk of diabetic complications and death [25]. In T2DM patients :
- For every 10% increase in TIR, the risk of major adverse cardiovascular events (MACE) decreases by 6%, and the risk of severe hypoglycemia decreases by 10%;
- For every 10% increase in TBR, the risk of severe hypoglycemia increases by 32%;
- Compared with TIR ≤ 50%, when TIR > 70%, the risk of microvascular events (such as retinopathy, chronic kidney disease) is reduced by 40%.
The latest Chinese Guidelines for the Prevention and Treatment of Diabetes (2024 Edition)[26] also recommends incorporating the TIR indicator into blood glucose control management.
Figure 5. Guidelines for the Prevention and Treatment of Diabetes in China (2024 Edition)
Summary
It is precisely these solid and continuously accumulated evidence-based findings that have driven the rapid upgrading of recommendations in just a few years by authoritative guidelines such as those from the ADA, the annual meeting of the European Association for the Study of Diabetes (EASD), and many of our country's authoritative guidelines — expanding the application of CGM from specific patient groups to almost all diabetic populations. It is foreseeable that with the popularization of CGM and the continuous iteration of technology, diabetes management is moving from traditional "static monitoring" to a true sense of "dynamic, continuous, and precision medicine"; future blood glucose management will be safer, more efficient, and achieve more refined individualized regulation.
Reference：
[1]Tamborlane WV, Beck RW, Bode BW, et al.;Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group. Continuous glucose monitoring and intensive treatment of type 1 diabetes. N Engl J Med 2008;359:1464–1476
[2]Tumminia A, Crimi S, Sciacca L, et al. Efficacyof real-time continuous glucose monitoring on glycaemic control and glucose variability in type 1diabetic patients treated with either insulin pumps or multiple insulin injection therapy: a randomized controlled crossover trial. Diabetes Metab Res Rev 2015;31:61–68
[3]Beck RW, Riddlesworth T, Ruedy K, et al.;DIAMOND Study Group. Effect of continuous glucose monitoring on glycemic control in adults with type 1 diabetes using insulin injections: the DIAMOND randomized clinical trial. JAMA 2017;317:371–378
[4]Lind M, Polonsky W, Hirsch IB, et al.Continuous glucose monitoring vs conventional therapy for glycemic control in adults with type 1diabetes treated with multiple daily insulininjections: the GOLD randomized clinical trial.JAMA 2017;317:379–387
[5]Riddlesworth T, Price D, Cohen N, Beck RW.Hypoglycemic event frequency and the effect of continuous glucose monitoring in adults withtype 1 diabetes using multiple daily insulin injections. Diabetes Ther 2017;8:947–951
[6]Sequeira PA, Montoya L, Ruelas V, et al.Continuous glucose monitoring pilot in lowincome type 1 diabetes patients. Diabetes Technol Ther 2013;15:855–858
[7]Bolinder J, Antuna R, Geelhoed-Duijvestijn P, Kroger J, Weitgasser R. Novel glucose-sensing technology and hypoglycaemia in type 1 diabetes: a multicentre, non-masked, randomised controlled trial. Lancet 2016;388:2254–2263
[8]Hermanns N, Schumann B, Kulzer B, Haak T. The impact of continuous glucose monitoring on low interstitial glucose values and low blood glucose values assessed by point-of-care blood glucose meters: results of a crossover trial. J Diabetes Sci Technol 2014;8:516–522
[9]Continuous glucose monitoring for patients with type 1 diabetes and impaired awareness of hypoglycaemia (IN CONTROL): a randomised, open-label, crossover trial. Lancet Diabetes Endocrinol 2016;4:893–902
[10]Tamborlane WV, Beck RW, Bode BW, et al.; Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group. Continuous glucose monitoring and intensive treatment of type 1 diabetes. N Engl J Med 2008;359:1464–1476
[11]Strategies to Enhance New CGM Use in Early Childhood (SENCE) Study Group. A randomized clinical trial assessing continuous glucose monitoring (CGM) use with standardized education with or without a family behavioral intervention compared with fingerstick blood glucose monitoring in very young children with type 1 diabetes. Diabetes Care 2021;44:464–472
[12]Van Name MA, Kanapka LG, DiMeglio LA, et al. Long-term continuous glucose monitor use in very young children with type 1 diabetes: oneyear results from the SENCE study. J Diabetes Sci Technol 2023;17:976–987
[13]Laffel LM, Kanapka LG, Beck RW, et al.; CGM Intervention in Teens and Young Adults with T1D (CITY) Study Group; CDE10. Effect of continuous glucose monitoring on glycemic control in adolescents and young adults with type 1 diabetes: a randomized clinical trial. JAMA 2020;323:2388– 2396
[14]Chinese Diabetes Society, Chinese Medical Doctor Association Endocrinology and Metabolism Branch, Chinese Medical Association Endocrinology Branch, etc. China Type 1 Diabetes Diagnosis and Treatment Guidelines (2021 Edition). Chinese Journal of Diabetes, 2022,14(11):1143-1250. DOI: 10.3760/cma.j.cn115791-20220916-00474
[15]Beck RW, Riddlesworth TD, Ruedy K, et al.; DIAMOND Study Group. Continuous glucose monitoring versus usual care in patients with type 2 diabetes receiving multiple daily insulin injections: a randomized trial. Ann Intern Med 2017;167:365–374
[16]Martens T, Beck RW, Bailey R, et al.; MOBILE Study Group. Effect of continuous glucose monitoring on glycemic control in patients with type 2 diabetes treated with basal insulin: a randomized clinical trial. JAMA 2021;325:2262– 2272
[17]Price DA, Deng Q, Kipnes M, Beck SE. Episodic real-time CGM use in adults with type 2 diabetes: results of a pilot randomized controlled trial. Diabetes Ther 2021;12:2089–2099
[18]Ehrhardt NM, Chellappa M, Walker MS, Fonda SJ, Vigersky RA. The effect of real-time continuous glucose monitoring on glycemic control in patients with type 2 diabetes mellitus. J Diabetes Sci Technol 2011;5:668–675
[19]Yoo HJ, An HG, Park SY, et al. Use of a real time continuous glucose monitoring system as a motivational device for poorly controlled type 2 diabetes. Diabetes Res Clin Pract 2008;82:73–79
[20]Grace T, Salyer J. Use of real-time continuous glucose monitoring improves glycemic control and other clinical outcomes in type 2 diabetes patients treated with less intensive therapy. Diabetes Technol Ther 2022;24:26–31 11. Patil SP, Albanese-O’Neill A
[21]Aleppo G, Beck RW, Bailey R, et al.; MOBILE Study Group; Type 2 Diabetes Basal Insulin Users: The Mobile Study (MOBILE) Study Group. The effect of discontinuing continuous glucose monitoring in adults with type 2 diabetes treated with basal insulin. Diabetes Care 2021;44:2729– 2737
[22]Garg SK, Hirsch IB, Repetto E, Snell-Bergeon J, Ulmer B, Perkins C, Bergenstal RM. Impact of continuous glucose monitoring on hospitalizations and glucose control in people with type 2 diabetes: real-world analysis. Diabetes Obes Metab. 2024 Nov;26(11):5202-5210. doi: 10.1111/dom.15866. Epub 2024 Sep 12.
[23]National Clinical Research Center for Metabolic Diseases (Changsha), China Type 1 Diabetes Alliance. Expert Consensus on the Application of Technology Related to Type 1 Diabetes Management in China (2025 Edition) [J]. Chinese Journal of Diabetes,2025,17(10)：1242-1260.DOI:10.3760/cma.j.cn115791-20250727-00383
[24]Rodbard D. Continuous glucose monitoring metrics (Mean Glucose, time above range and time in range) are superior to glycated haemoglobin for assessment of therapeutic efficacy. Diabetes Obes Metab. 2023 Feb;25(2):596-601. doi: 10.1111/dom.14906. Epub 2022 Dec 1.
[25]Bergenstal RM, et al. Diabetes Technol Ther，2023，25(6):378-383.
[26]Chinese Diabetes Society. China Diabetes Prevention and Treatment Guidelines (2024 Edition) [J]. Chinese Journal of Diabetes, 2024, preprint online. DOI:10.3760/cma.j.cn115791-20241203-00705.