Clinical Question: 

A 49 year old female with past medical history of HTN and T2DM presents for their annual visit. She wanted to know if continuous glucose monitoring versus self monitoring has an impact on glycemic control. I wanted to explore which method of glucose monitoring one is more beneficial for Type 1 and Type 2 diabetes.

 

PICO Question:

In patients with diabetes, does continuous glucose monitoring compared to self-monitoring of blood glucose show improved outcomes, such as better glycemic control? 

P	I	C	O
Diabetic patients	Blood glucose monitoring	Continuous glucose monitoring	Improved glycemic control
Type 1 Diabetes		Self monitoring of blood glucose	HbA1C levels
Type 2 Diabetes		Flash monitoring	Hypoglycemic events

 

Database Search:

Pubmed

Search Criteria: continuous glucose monitoring versus self monitoring in diabetes

Filters: free full text, last 10 years, clinical trial, meta-analysis, RCT, systematic review

Results: 85

 

Science Direct

Search Criteria: comparison of continuous glucose monitoring versus self monitoring in diabetic patients

Filters: 2014-2024, review articles, English

Results: 530

 

Cochrane

Search Criteria:  continuous glucose monitoring versus self monitoring in diabetic patients 

Filters: 2014-2024, review articles

Results: 1

 

Search Strategy: I noticed that this search criteria did not yield as many results on PubMed as my usual PICO searches. I read through the titles and a few of the abstracts on the first three pages of each search engine (except for Cochrane which only yielded one result). I focused on trying to find articles with high levels of evidence and most recent findings. I wanted to pick articles that demonstrated the impact of self blood glucose monitoring as opposed to continuous blood glucose monitoring, using variables such as HbA1c levels, reduction of hypoglycemic episodes, and patient satisfaction. 

 

Articles Chosen (5 or more) for Inclusion (please copy and paste the abstract with link):

 

Article 1: 

Janapala RN, Jayaraj JS, Fathima N, et al. Continuous Glucose Monitoring Versus Self-monitoring of Blood Glucose in Type 2 Diabetes Mellitus: A Systematic Review with Meta-analysis. Cureus. 2019;11(9):e5634. Published 2019 Sep 12. doi:10.7759/cureus.5634

 

Why I chose this article: This article directly answers my PICO question and has a high level of evidence, as it is a systematic review with meta-analysis. It comprehensively compares CGM and SMBG in diabetes management, focusing on key outcomes like HbA1c reduction, hypoglycemia detection, and patient satisfaction. 

 

Abstract

Every eleventh adult has diabetes, and every third has prediabetes. Over 95% of diabetics are of type 2. It is well established that diabetes doubles the risk of heart disease and stroke apart from increasing the risk of microvascular complications. Hence, strict glycemic control is necessary. However, it increases the risk of hypoglycemia, especially in patients with longstanding diabetes. Continuous glucose monitors (CGM) use a sensor to continuously measure the glucose levels in the interstitial fluid every 10 seconds and gives out mean values every five minutes. CGMs are emerging tools in the management of type 2 diabetes. The prime objective of this review is to find out if there is enough supporting evidence, suggesting that continuous glucose monitoring is more effective than self-monitoring of blood glucose (SMBG) in type 2 diabetes. We conducted a systematic literature search in Medline (PubMed) looking for any studies addressing our objective. It is observed that there is a varying level of evidence supporting that employing a CGM can reduce glycated hemoglobin (HbA1c), hypoglycemic events, and increase patient satisfaction. However, some studies reported no significant benefits. This systematic review with meta-analysis concludes that the use of CGM in type 2 diabetes mellitus (T2DM) is beneficial, as it significantly reduces HbA1c compared to the usual method of SMBG. The pooled mean difference in HbA1c was -0.25 (-0.45, -0.06) and statistically significant (at p = 0.01) when comparing CGM to SMBG.

 

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Article 2:

Martens T, Beck RW, Bailey R, et al. 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(22):2262-2272. doi:10.1001/jama.2021.7444

 

Why I chose this article: This article directly addressed my PICO question as the outcomes measured, including HbA1c levels, time spent in target glucose ranges, and incidence of hypoglycemia, evaluated the effectiveness of CGM in clinical practice compared to traditional BGM methods. It also had a high level of evidence as it is a randomized controlled trial. 

 

Abstract

Importance

Continuous glucose monitoring (CGM) has been shown to be beneficial for adults with type 2 diabetes using intensive insulin therapy, but its use in type 2 diabetes treated with basal insulin without prandial insulin has not been well studied.

 

Objective

To determine the effectiveness of CGM in adults with type 2 diabetes treated with basal insulin without prandial insulin in primary care practices.

 

Design, Setting, and Participants

This randomized clinical trial was conducted at 15 centers in the US (enrollment from July 30, 2018, to October 30, 2019; follow-up completed July 7, 2020) and included adults with type 2 diabetes receiving their diabetes care from a primary care clinician and treated with 1 or 2 daily injections of long- or intermediate-acting basal insulin without prandial insulin, with or without non insulin glucose-lowering medications.

 

Interventions

Random assignment 2:1 to CGM (n = 116) or traditional blood glucose meter (BGM) monitoring (n = 59).

 

Main Outcomes and Measures

The primary outcome was hemoglobin A1c (HbA1c) level at 8 months. Key secondary outcomes were CGM-measured time in target glucose range of 70 to 180 mg/dL, time with glucose level at greater than 250 mg/dL, and mean glucose level at 8 months.

 

Results

Among 175 randomized participants (mean [SD] age, 57 [9] years; 88 women [50%]; 92 racial/ethnic minority individuals [53%]; mean [SD] baseline HbA1c level, 9.1% [0.9%]), 165 (94%) completed the trial. Mean HbA1c level decreased from 9.1% at baseline to 8.0% at 8 months in the CGM group and from 9.0% to 8.4% in the BGM group (adjusted difference, −0.4% [95% CI, −0.8% to −0.1%]; P = .02). In the CGM group, compared with the BGM group, the mean percentage of CGM-measured time in the target glucose range of 70 to 180 mg/dL was 59% vs 43% (adjusted difference, 15% [95% CI, 8% to 23%]; P < .001), the mean percentage of time at greater than 250 mg/dL was 11% vs 27% (adjusted difference, −16% [95% CI, −21% to −11%]; P < .001), and the means of the mean glucose values were 179 mg/dL vs 206 mg/dL (adjusted difference, −26 mg/dL [95% CI, −41 to −12]; P < .001). Severe hypoglycemic events occurred in 1 participant (1%) in the CGM group and in 1 (2%) in the BGM group.

 

Conclusions and Relevance

Among adults with poorly controlled type 2 diabetes treated with basal insulin without prandial insulin, continuous glucose monitoring, as compared with blood glucose meter monitoring, resulted in significantly lower HbA1c levels at 8 months.

 

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Article 3:

Reddy M, Jugnee N, Anantharaja S, Oliver N. Switching from Flash Glucose Monitoring to Continuous Glucose Monitoring on Hypoglycemia in Adults with Type 1 Diabetes at High Hypoglycemia Risk: The Extension Phase of the I HART CGM Study. Diabetes Technol Ther. 2018;20(11):751-757. doi:10.1089/dia.2018.0252

 

Why I chose this article: This article has a high level of evidence as it is a randomized controlled trial and directly addresses my PICO question. It assesses clinically meaningful outcomes such as percentage time spent in hypoglycemia and glycemic control measured by HbA1c.

 

Abstract

Background: The I HART CGM study showed that real-time continuous glucose monitoring (RT-CGM) has greater beneficial impact on hypoglycemia than intermittent flash glucose monitoring (flash) in adults with type 1 diabetes (T1D) at high risk. The impact of continuing RT-CGM or switching from flash to RT-CGM for another 8 weeks was then evaluated.

Methods: Prospective randomized parallel group study with an extension phase. After a 2-week run-in with blinded CGM, participants were randomized to either RT-CGM or flash for 8 weeks. All participants were then given the option to continue with RT-CGM for another 8 weeks. Glycemic outcomes at 8 weeks are compared with the 16-week endpoint.

Results: Forty adults with T1D on intensified multiple daily insulin injections and with impaired awareness of hypoglycemia or a recent episode of severe hypoglycemia were included (40% female, median [IQR] age 49.5 [37.5-63.5] years, diabetes duration 30.0 [21.0-36.5] years, HbA1c 56 [48-63] mmol/mol, and Gold Score 5 [4-5]), of whom 36 completed the final 16-week extension. There was a significant reduction in percentage time in hypoglycemia (<3.0 mmol/L) in the group switching from flash to RT-CGM (from 5.0 [3.7-8.6]% to 0.8 [0.4-1.9]%, P = 0.0001), whereas no change was observed in the RT-CGM group continuing with the additional 8 weeks of RT-CGM (1.3 [0.4-2.8] vs. 1.3 [0.8-2.5], P = 0.82). Time in target (3.9-10 mmol/L) increased in the flash group after switching to RT-CGM (60.0 [54.5-67.8] vs. 67.4 [56.3-72.4], P = 0.02) and remained the same in the RT-CGM group that continued with RT-CGM (65.9 [54.1-74.8] vs. 64.9 [49.2-73.9], P = 0.64).

Conclusions: Our data suggest that switching from flash to RT-CGM has a significant beneficial impact on hypoglycemia outcomes and that continued use of RT-CGM maintains hypoglycemia risk benefit in this high-risk population.

 

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Article 4:

Pratley RE, Kanapka LG, Rickels MR, et al. Effect of Continuous Glucose Monitoring on Hypoglycemia in Older Adults With Type 1 Diabetes: A Randomized Clinical Trial. JAMA. 2020;323(23):2397-2406. doi:10.1001/jama.2020.6928

 

Why I chose this article: This article addresses my PICO question as it directly compares CGM and SMBG in a controlled, older adult population with type 1 diabetes, focusing on key outcomes like hypoglycemia and glycemic control. Additionally, it has a high level of evidence as it is a randomized controlled trial. 

 

Abstract

Importance: Continuous glucose monitoring (CGM) provides real-time assessment of glucose levels and may be beneficial in reducing hypoglycemia in older adults with type 1 diabetes.

 

Objective: To determine whether CGM is effective in reducing hypoglycemia compared with standard blood glucose monitoring (BGM) in older adults with type 1 diabetes.

 

Design, setting, and participants: Randomized clinical trial conducted at 22 endocrinology practices in the United States among 203 adults at least 60 years of age with type 1 diabetes.

 

Interventions: Participants were randomly assigned in a 1:1 ratio to use CGM (n = 103) or standard BGM (n = 100).

 

Main outcomes and measures: The primary outcome was CGM-measured percentage of time that sensor glucose values were less than 70 mg/dL during 6 months of follow-up. There were 31 prespecified secondary outcomes, including additional CGM metrics for hypoglycemia, hyperglycemia, and glucose control; hemoglobin A1c (HbA1c); and cognition and patient-reported outcomes, with adjustment for multiple comparisons to control for false-discovery rate.

 

Results: Of the 203 participants (median age, 68 [interquartile range {IQR}, 65-71] years; median type 1 diabetes duration, 36 [IQR, 25-48] years; 52% female; 53% insulin pump use; mean HbA1c, 7.5% [SD, 0.9%]), 83% used CGM at least 6 days per week during month 6. Median time with glucose levels less than 70 mg/dL was 5.1% (73 minutes per day) at baseline and 2.7% (39 minutes per day) during follow-up in the CGM group vs 4.7% (68 minutes per day) and 4.9% (70 minutes per day), respectively, in the standard BGM group (adjusted treatment difference, -1.9% (-27 minutes per day); 95% CI, -2.8% to -1.1% [-40 to -16 minutes per day]; P <.001). Of the 31 prespecified secondary end points, there were statistically significant differences for all 9 CGM metrics, 6 of 7 HbA1c outcomes, and none of the 15 cognitive and patient-reported outcomes. Mean HbA1c decreased in the CGM group compared with the standard BGM group (adjusted group difference, -0.3%; 95% CI, -0.4% to -0.1%; P <.001). The most commonly reported adverse events using CGM and standard BGM, respectively, were severe hypoglycemia (1 and 10), fractures (5 and 1), falls (4 and 3), and emergency department visits (6 and 8).

 

Conclusions and relevance: Among adults aged 60 years or older with type 1 diabetes, continuous glucose monitoring compared with standard blood glucose monitoring resulted in a small but statistically significant improvement in hypoglycemia over 6 months. Further research is needed to understand the long-term clinical benefit.

 

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Article 5:

Seyed Ahmadi S, Westman K, Pivodic A, et al. The Association Between HbA1c and Time in Hypoglycemia During CGM and Self-Monitoring of Blood Glucose in People With Type 1 Diabetes and Multiple Daily Insulin Injections: A Randomized Clinical Trial (GOLD-4). Diabetes Care. 2020;43(9):2017-2024. doi:10.2337/dc19-2606

 

Why I chose this article: This article is a randomized controlled trial so it has a high level of evidence. Additionally, it directly answers my PICO question as it compares the time in hypoglycemia and HbA1c levels in patients using CGM and SMBG in patients with T1D. 

 

Abstract

Objective: According to recent guidelines, individuals with type 1 diabetes should spend <4.0% of time per day with glucose levels <3.9 mmol/L (<70 mg/dL) and <1.0% per day with glucose levels <3.0 mmol/L (<54 mg/dL).

 

Research design and methods: In the GOLD randomized crossover trial, 161 individuals with type 1 diabetes treated with multiple daily insulin injections (MDI) were randomized to continuous glucose monitoring (CGM) or conventional therapy with self-monitoring of blood glucose (SMBG) and evaluated over 16 months. We estimated the association between time spent in hypoglycemia and various mean glucose and HbA1c levels.

 

Results: Time spent in hypoglycemia (<3.9 mmol/L and <3.0 mmol/L) increased significantly with lower mean HbA1c and mean glucose levels during both CGM and conventional therapy. During CGM, 24 (57.1%) individuals with HbA1c <7.5% (<58 mmol/mol) had <1.0% time spent in hypoglycemia <3.0 mmol/L and 23 (54.8%) had <4.0% time spent in hypoglycemia <3.9 mmol/L. During CGM, mean time spent in hypoglycemia for individuals with mean HbA1c 7.0% (52 mmol/mol) was estimated to be 5.4% for <3.9 mmol/L and 1.5% for <3.0 mmol/L. The corresponding values during SMBG were 9.2% and 3.5%, respectively. Individuals with mean glucose levels of 8 mmol/L spent 4.9% units more time with glucose levels <3.9 mmol/L and 2.8% units more time <3.0 mmol/L during SMBG compared with CGM.

 

Conclusions: Reaching current targets for time in hypoglycemia while at the same time reaching HbA1c targets is challenging for patients with type 1 diabetes treated with MDI both with CGM and SMBG monitoring. However, CGM is associated with considerably less time in hypoglycemia than SMBG at a broad range of HbA1c levels and is crucial for patients with MDI treatment if they are to have a chance to approach hypoglycemia targets.

 

Summary of the Evidence:

Author (Date)	Level of Evidence	Sample/Setting (# of subjects/ studies, cohort definition etc)	Outcome(s) studied	Key Findings	Limitations and Biases
Rajesh Naidu Janapala, Joseph S Jayaraj, Nida Fathima,  Tooba Kashif, Norina Usman, Amulya Dasari, Nusrat Jahan, and Issac Sachmechi (2019).	Systematic Review with meta analysis	– Conducted a systematic literature search in MEDLINE (PubMed) through a combination of both Mesh terms and keywords – Included studies that compare CGM of blood glucose to SMBG in T2DM patients – Included studies that measure HbA1c as an outcome and has a baseline mean HbA1c ≥6.5%	– Primary outcome: difference of mean HbA1c in the CGM group compared to the SMBG group at the end of the studies – Also measured episodes of hypoglycemia, glucose variability, and patient satisfaction.	– CGM usage in T2DM patients is associated with a significant reduction in HbA1c compared to SMBG, demonstrating better glycemic control. – CGMs detect more hypoglycemic events, especially nocturnal ones, compared to SMBG, providing timely alerts to prevent severe hypoglycemia. – CGMs offer detailed data on glucose variability and increase the time spent in the target glycemic range (70-180 mg/dl), which SMBG cannot effectively capture. – High patient satisfaction and compliance with CGM usage were noted, attributed to the real-time feedback on diet and exercise, which encourages lifestyle modifications. – CGMs are expensive and may have accuracy issues at low glucose levels due to the time lag between interstitial and blood glucose measurements.	– Literature search was conducted only in one database, Medline (PubMed) database.  – Studies published in other than the English language have not been reviewed.  – No detailed sensitivity analysis is performed due to the small sample size of the studies.  – No cost-benefit analysis was studied during this review
Thomas Martens, Roy W. Beck, Ryan Bailey, Katrina J. Ruedy, Peter Calhoun, Anne L. Peters, Rodica Pop-Busui, Athena Philis-Tsimi, Shichun Bao, Guillermo Umpierrez, Georgia Davis, Davida Kruger, Anuj Bhargava, Laura Young, Janet B. McGill, Grazia Aleppo, Quang T. Nguyen, Ian Orozco, William Biggs, K. Jean Lucas, William H. Polonsky, John B. Buse, David Price, and Richard M. Bergenstal (2021).	Randomized Clinical Trial	– Patients 30 years or older, diagnosed with T1D treated with 1 or 2 daily injections of long- or intermediate-acting basal insulin for at least 6 months, locally measured HbA1c level of 7.8% to 11.5%.  – Sample size: 207	– Primary outcome: HbA1c level at 8 months adjusted for the baseline value. – Secondary outcome: CGM-measured time in the target glucose range of 70 to 180 mg/dL, time at greater than 250 mg/dL for glucose, and mean glucose level at 8 months adjusted for the baseline value.	– Participants using CGM showed a statistically significant decrease in mean HbA1c levels from baseline to 8 months compared to those using SMBG (8.0% vs. 8.4%, adjusted mean difference −0.4% [95% CI, −0.8% to −0.1%], P = .02). – CGM users spent significantly more time within the target glucose range of 70 to 180 mg/dL (59% vs. 43%, P < .001) and less time with glucose levels above 250 mg/dL (11% vs. 27%, P < .001) compared to SMBG users. – Throughout the day, CGM users demonstrated lower mean glucose levels compared to BGM users (179 mg/dL vs. 206 mg/dL, P < .001). – There was a reduction in CGM-measured hypoglycemia compared to SMBG, with significant differences observed in time spent below 54 mg/dL (P = .001) and below 70 mg/dL (P = .02) at 8 months.	– The study only followed participants for 8 months, leaving uncertainty about the long-term sustainability of the observed benefits of CGM. – The COVID-19 pandemic necessitated virtual visits for some participants, leading to missing data for HbA1c and CGM outcomes at the 8-month mark. – A significant proportion of the CGM group still had HbA1c levels above 8% after 8 months.
Monika Reddy, Narvada Jugnee, Sinthuka Anantharaja, Nick Oliver (2018).	Randomized Controlled Trial	– 40 adults age ≥18 years, T1D ≥3 years, on an intensified MDI regimen for >6 months, and a severe hypoglycemic event in the last 12 months requiring third-party assistance or a Gold Score ≥4. – They were switched from FGM to CGM after 8 weeks.	– Primary outcomes: percentage time spent in hypoglycemia – Secondary outcomes: percentage time in euglycemia (3.9–7.8 mmol/L), percentage time spent in target (3.9–10 mmol/L), percentage time spent in hyperglycemia.	– Switching from flash glucose monitoring to CGM resulted in a significant reduction in percentage time spent in clinically relevant hypoglycemia (<3.0 mmol/L) (5.0% vs. 0.8%, P < 0.001).  – Study supports using CGM, especially with alarms, as the preferred option in T1D patients at high risk of hypoglycemia.  – There was no significant change in HbA1c within or between groups.	– Study has a small sample size and relatively short follow-up period, which may limit the generalizability and long-term assessment of outcomes.  – The use of different glucose monitoring technologies at different time points introduces variability and potential inaccuracies in comparing glucose outcomes between the groups.  – While both devices were used according to manufacturer guidelines, the known tendency for flash glucose monitoring to overestimate hypoglycemia could have influenced specific outcome measures related to hypoglycemia.
Richard E Pratley, Lauren G Kanapka, Michael R Rickels, Andrew Ahmann, Grazia Aleppo, Roy Beck, Anuj Bhargava, Bruce W Bode, Anders Carlson, Naomi S Chaytor, D Steven Fox, Robin Goland, Irl B Hirsch, Davida Kruger, Yogish C Kudva, Carol Levy, Janet B McGill, Anne Peters, Louis Philipson, Athena Philis-Tsimik, Rodica Pop-Busui, Viral N Shah, Michael Thompson, Francesco Vendrame, Alandra Verdejo, Ruth S Weinstock, Laura Young, Kellee M Miller (2020)	Randomized Clinical Trial	– RCT conducted at 22 endocrinology practices in the US among 203 adults at least 60 years of age with T1D.	– Primary outcome: CGM measured percentage of time that sensor glucose values were less than 70 mg/dL during 6 months of follow-up – Secondary outcomes: hypoglycemia, hyperglycemia, and glucose control; HbA1c; and cognition and patient-reported outcomes.	– Among older adults with T1D, CGM use led to a statistically significant reduction in time spent with hypoglycemia compared to SMBG. – The risk of severe hypoglycemia was significantly reduced with CGM use, especially in those with higher baseline hypoglycemia and glycemic variability. – The reduction in hypoglycemia was consistent across various age groups, HbA1c ranges, cognitive statuses, and education levels.	– Participants had high socioeconomic status, specialized diabetes care, and good baseline glycemic control.  – Intervention period was short at six months.  – An older CGM sensor version was used, and it’s uncertain if newer features would enhance CGM use. – The CGM group had more severe hypoglycemia events prior to the study.
Shilan Seyed Ahmadi, Klara Westman, Aldina Pivodic, Arndís F. Ólafsdóttir, Sofia Dahlqvist, Irl B. Hirsch, Jarl Hellman, Magnus Ekelund, Tim Heise, William Polonsky,  Magnus Wijkman, Erik Schwarcz, and Marcus Lind (2020).	Randomized Controlled Trial	– 161 individuals with T1D treated with multiple daily insulin injections were randomized to  CGM or SMBG and evaluated over 16 months. – Participants were required to have diabetes duration >1 year and fasting C-peptide levels <0.91 ng/mL (<0.3 nmol/L).	– Primary outcome: total time spent in hypoglycemia, TIR, hyperglycemia, and glycemic variability. – Secondary outcomes: association between percentage of time with glucose levels 3.9–10.0 mmol/L and time in hypoglycemia <3.9 mmol/L (<70 mg/dL) and <3.0 mmol/L (<54 mg/dL).	– CGM significantly reduced time spent in hypoglycemia compared to SMBG particularly in patients using multiple daily injections for insulin therapy. – Patients using both CGM and SMBG struggled to meet recommended targets for time spent in hypoglycemia, especially at HbA1c levels below 7.5% but CGM showed somewhat better outcomes compared to SMBG.	– Few patients achieved the general HbA1c target of 7.0% even during conventional therapy.  – Many patients with higher HbA1c levels (7.5%) did not meet hypoglycemia targets.  – The study used older CGM technology, which required calibrations, whereas newer models like the Dexcom G6 offer improved accuracy and no calibration requirement.  – Study was conducted in adults who were likely to wear CGM devices most of the time, limiting its generalizability to children and a broader T1D population.

Conclusion(s):

Article 1: CGM significantly improves glycemic control in T2DM patients, as there was a notable reduction in HbA1c compared to SMBG. CGMs are more effective at detecting hypoglycemic events, particularly nocturnal ones, providing timely alerts to prevent severe episodes. They also offer detailed data on glucose variability and increase the time spent within the target glycemic range, which SMBG cannot accurately capture. High patient satisfaction and compliance with CGM are reported. 

 

Article 2: CGM significantly enhances glycemic management in individuals with diabetes compared to SMBG. CGM users achieved a notable reduction in mean HbA1c levels over 8 months, along with spending more time within the target glucose range of 70 to 180 mg/dL and less time with elevated glucose levels above 250 mg/dL. Additionally, CGM users consistently maintained lower mean glucose levels throughout the day compared to BGM users. Importantly, CGM showed promising indications of reducing hypoglycemic events, with significant improvements observed in time spent below critical thresholds of 54 mg/dL and 70 mg/dL. 

 

Article 3: CGM offers significant benefits over flash glucose monitoring and traditional self-monitoring of blood glucose (SMBG) in adults with type 1 diabetes (T1D) who are at high risk of hypoglycemia. CGM demonstrated a substantial reduction in the percentage of time spent in clinically relevant hypoglycemia (<3.0 mmol/L) compared to FGM, with sustained improvements over a 16-week period. Although there was no significant change in HbA1c levels, CGM consistently improved time in target glucose range, suggesting enhanced glycemic control compared to FGM.

 

Article 4: CGM significantly improves glycemic control by reducing the time spent in hypoglycemia for older adults with T1D compared to SMBG. The benefits of CGM are consistent across various demographics and baseline conditions, including age, HbA1c levels, cognitive status, and education levels. CGM also reduces the risk of severe hypoglycemia, particularly in patients with higher baseline hypoglycemia and glycemic variability. 

 

Article 5: CGM offers significant benefits over SMBG  in reducing time spent in hypoglycemia among patients with T1D using multiple daily injections. Despite these benefits, many patients still struggle to achieve recommended targets for hypoglycemia and HbA1c levels, particularly at lower HbA1c thresholds. 

 

Overarching Conclusion: 

The articles collectively highlight that continuous glucose monitoring significantly enhances glycemic control compared to traditional self-monitoring of blood glucose in diabetes management. CGM users consistently achieve lower HbA1c levels and spend more time within the optimal glucose range of 70 to 180 mg/dL, while also experiencing fewer instances of elevated glucose levels above 250 mg/dL. Importantly, CGM proves effective in detecting and preventing hypoglycemic events, particularly nocturnal ones, through real-time alerts. This capability contributes to improved patient outcomes, including reduced time spent in clinically significant hypoglycemia. Despite these benefits, challenges such as cost and occasional accuracy issues at low glucose levels remain barriers to widespread adoption. The findings emphasize the potential of CGM to mitigate severe hypoglycemia risks across diverse patient demographics, but ongoing advancements are necessary to optimize effectiveness and accessibility in diabetes care.

 

Clinical Bottom Line:

Weight of the evidence 

This paper analyzes four articles, and weighs them in the following order: Article 1, Article 2, Article 4, Article 5, Article 3.

Article 1 is a systematic review with meta-analysis that examined 5 studies with 382 subjects. It is a recent article from 2019. Cumulative analysis of the data from all five RCTs was done using RevMan 5 tool. Additionally, the primary outcome was change in the HbA1c, which is exactly what my PICO question was addressing. They also examined episodes of hypoglycemia and patient satisfaction. One weakness of this article is that they only used one database to find their studies. Additionally, it failed to include a cost analysis and the sample size was relatively small, at 382 subjects.

Article 2 is a randomized controlled trial including 207 participants. It has a higher sample size than Article 5 and is a relatively recent article from 2021. It also measured the HbA1c level at 8 months, making it a relatively longer treatment window compared to Article 4. One weakness of this article is that the patients had greater contact with clinic staff than patients normally do, which limits the applicability to most routine practice settings. 

Article 4 is a randomized clinical trial that included 203 participants. It is a relatively recent study, from 2020. It directly answers my PICO question as its primary outcome was the percentage of time with controlled glucose levels. One strength of this article is that they assessed modification of treatment effect by baseline variables. They adjusted for potential confounding variables. One weakness of this article is that the intervention period was short, at 6 months. Additionally, participants had high socioeconomic status, specialized diabetes care, and good baseline glycemic control, which limits applicability to the general population. 

Article 5 is a randomized controlled trial with 161 participants, making the sample size smaller than the previous three articles mentioned. This study is relatively recent as well, from 2020. This study ensured detailed handling of CGM data and consistent use of the same CGM system across patients. Centralized analysis of HbA1c adds reliability to the findings. One weakness of this article is that some patients did not achieve hypoglycemia targets even at higher HbA1c levels. The study also acknowledges that CGM technology has advanced since the study was conducted.

Article 3 is a randomized controlled study with 40 adults, making the sample size the smallest out of the other 5 articles. It is also the oldest article, from 2018. It also has the smallest treatment window, at 8 weeks and 16 weeks. However, this article directly addressed my PICO question as it analyzed the episodes of severe hypoglycemia and the reduction in time in hypoglycemia after switching from one method of glucose monitoring to CGM.

 

Magnitude of any effects

All the articles were largely unanimous in their conclusions that CGM is effective in improving outcomes for various kinds of diabetes. CGM consistently shows improvements in glycemic control by significantly reducing HbA1c levels and increasing the time spent within the target glucose range of 70 to 180 mg/dL. CGM enhances patient satisfaction and compliance with diabetes management, likely due to its user-friendly nature and immediate feedback on glucose levels. These benefits are observed across diverse demographic groups, including older adults and those with both type 1 and type 2 diabetes, highlighting CGM’s broad applicability in diabetes care. 

 

Clinical significance 

Based on these five articles, it can be concluded that continuous glucose monitoring is beneficial in managing both Type 1 and Type 2 diabetes. It lowers HbA1c levels and keeps blood sugar levels within a healthy range (70-180 mg/dL). Using CGM also provides more concrete data for patients and doctors, regarding how blood sugar levels fluctuate throughout the day. This helps adjust insulin doses and lifestyle habits more effectively to keep blood sugar levels balanced. The studies also prove that CGM works well for different age groups, such as older adults and people with type 1 or type 2 diabetes. In conclusion, I believe that using CGM should be a regular part of diabetes management. It helps improve blood sugar controlled, which in turn lowers the risk of health complications related to diabetes.