• Diabetes Technology

CGM can optimize therapy control for T1D and T2D

  • Uncategorized
  • 9 minute read

Modern technologies are becoming increasingly important for both type 1 diabetes (T1D) and type 2 diabetes (T2D). More and more patients are turning to continuous glucose monitoring (CGM). By coupling these systems with insulin pumps, the insulin supply can be automatically adjusted to the glucose values, enabling personalized treatment. As studies show, patient education is a decisive factor for the successful implementation of CGM systems.

While the method of continuous glucose monitoring (CGM) was initially mainly used in children, adolescents and adults with type 1 diabetes, CGM is now also a frequently used treatment option for people with type 2 diabetes or gestational diabetes [1]. CGM is a minimally invasive method in which a subcutaneous sensor measures the glucose levels in the interstitial fluid in the subcutaneous fatty tissue and these are transmitted either continuously (real-time CGM systems, rt-CGM) or intermittently (flash glucose monitoring, FGM; intermittent glucose monitoring, is-CGM) to a receiving device. Combined with an insulin pump and an algorithm for automatic insulin dosing, this is known as an AID (automated insulin delivery) system. The use of AID systems has been shown to lead to improvements in glucose profiles and a reduction in diabetes-related stress [2–4].

An article published in the journal Diabetes Care 2023 summarizes the current evidence on CGM in type 1 and type 2 diabetes [5].

rt-CGM and is-CGM in adult diabetics

Mostrandomized-controlled trials ( RCTs) in adults with type 1 diabetes show that rt-CGM leads to a lower HbA1c level [6–9] and a shorter time in the hypoglycemic range [10,11]. Although most RCTs did not aim to detect a reduction in the incidence of severe hypoglycemia, one study in people over 60 years of age with type 1 diabetes (i.e. a population at high risk of hypoglycemia) demonstrated a significant reduction in both the time in the hypoglycemic range and the number of severe hypoglycemic events [12].

Less stringent data are available on the use of is-CGM in adults with type 1 diabetes [15]. One RCT resulted in a shorter period of time in the hypoglycemic range without a significant change in HbA1c [13]. Several observational studies have shown a reduction in the HbA1c value [14] or a reduction in hypoglycemia without a change in the HbA1c value [15]. A systematic review of RCTs in adults with type 1 or type 2 diabetes suggests that is-CGM can reduce HbA1c in patients with type 1 diabetes or insulin-treated type 2 diabetes [16], while another systematic review (mainly T1D studies with randomized design or cohort studies) found a small (0.26%) but statistically significant reduction in HbA1c [17]. A meta-analysis of non-randomized studies in adults showed that HbA1c levels were generally reduced by around 0.5% after 12 months using CGM technologies [18]. Randomized controlled trials on the use of rt-CGM compared to standard blood glucose self-monitoring in adults with type 2 diabetes have generally shown a reduction in HbA1c levels without a significant change in the duration of hypoglycemia [19–22]. These studies were usually conducted in patients on insulin therapy and the interventions often included comprehensive patient education. Studies on the use of is-CGM in people with type 2 diabetes have shown heterogeneous results for both endpoints [17,23,24].

rt-CGM and is-CGM for diabetes in children and adolescents

A systematic review published in 2019, which included the most important randomized controlled trials published to date, shows that CGM in combination with automatic insulin deactivation prevents hypoglycemia, reduces hypoglycemia anxiety and improves quality of life. In addition, the time in range (TIR) increased and the HbA1c values improved [25]. The HbA1c reduction appears to be most pronounced in children and adolescents with initially higher HbA1c values. Well-controlled patients improve through better TIR and fewer hypoglycemias [26].

However, successful use of CGM systems is dependent on adequate training, as well as the ability and motivation to use this modern technology [26]. This is also reflected in a large study on rt-CGM in patients with type 1 diabetes [9]. While adults showed a significant reduction in HbA1c levels, no improvement in glucose control was observed in children (8-14 year olds) or adolescents and young adults (15-24 year olds). It was found that younger participants were significantly less likely to wear the CGM device than adults aged 25 and over, and that consistency of CGM use was highly correlated with lower HbA1c in all participants. A subsequent RCT, which was specifically aimed at adolescents and young adults and included extensive education and support measures, showed that participants randomized to rt-CGM had a significantly lower HbA1c level after six months than participants who had been ranodmized to conventional blood glucose self-monitoring [27].

The evidence for the use of rt-CGM in young children (under eight years of age) with type 1 diabetes is limited. Registry studies show correlations between the use of a CGM and a lower HbA1c value [28,19]. An RCT in infants showed no effect on HbA1c levels [30] and an uncontrolled study in infants with type 1 diabetes showed no evidence of improvement in blood glucose levels over a six-month period, but high parental satisfaction [31]. According to Sacks et al. There are no RCTs on the use of is-CGM in children [5], but observational studies suggest that is-CGM is associated with better quality of life and/or treatment satisfaction for children or their caregivers [32–35].

rt-CGM for T1D during pregnancy

An RCT on the use of rt-CGM during pregnancy in women with type 1 diabetes showed a modest but statistically significant reduction in HbA1c in women who were switched to rt-CGM compared with those who continued to use conventional self-monitoring of blood glucose, with no differences in severe hypoglycemia [5]. The rates of several adverse neonatal outcomes (e.g. neonatal intensive care unit admission, neonatal hypoglycemia) were lower in the group that was switched to rt-CGM [36]. An RCT of rt-CGM compared with conventional self-monitoring of blood glucose in women with gestational diabetes showed no significant differences in HbA1c or neonatal outcomes depending on the use of rt-CGM, but an association with lower weight gain [37].

Literature:

  1. Peek ME, Thomas CC: Broadening access to continuous glucose monitoring for patients with type 2 diabetes. JAMA 2021; 325(22): 2255-2257.
  2. Aiello EM, et al: Review of Automated Insulin Delivery Systems for Individuals with Type 1 Diabetes: Tailored Solutions for Subpopulations. Curr Opin Biomed Eng 2021; 19: 100312
  3. Gilbert TR, et al: Change in hemoglobinA1c and quality of life with real-time continuous glucose Monitoring Use by People with Insulin-Treated Diabetes in the Landmark Study. Diabetes Technol Ther 2021; 23(S1): S35-S39.
  4. Ware J; DAN05 Consortium: Cambridge hybrid closed-loop algorithm in children and adolescents with type 1 diabetes: a multicentre 6-month randomized controlled trial. Lancet Digit Health 2022; 4(4): e245-e255.
  5. Sacks DB, et al: Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus. Diabetes Care 2023 Oct 1; 46(10): e151-e199.
  6. Beck RW, et al: 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.
  7. Riddlesworth T, et al: Hypoglycemic event frequency and the effect of continuous glucose monitoring in adults with type 1 diabetes using multiple daily insulin injections. Diabetes Ther 2017; 8: 947-951.
  8. Lind M, et al: Continuous glucose monitoring vs conventional therapy for glycemic control in adults with type 1 diabetes treated with multiple daily insulin injections: the GOLD randomized clinical trial. JAMA 2017; 317: 379-387.
  9. Tamborlane WV, et al: Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group. Continuous glucose monitoring and intensive treatment of type 1 diabetes. New Engl J Med 2008;359: 1464-1476.
  10. Hermanns N, et al: 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.
  11. van Beers CAJ, et al: Continuous glucose monitoring for patients with type 1 diabetes and impaired awareness of hypoglycaemia (IN CONTROL): a randomized, open-label, crossover trial. Lancet Diabetes Endocrinol 2016; 4: 893-902.
  12. Pratley RE, et al: Effect of continuous glucose monitoring on hypoglycemia in older adults with type 1 diabetes: a randomized clinical trial. JAMA 2020; 323: 2397-2406.
  13. Bolinder J, et al: Novel glucose-sensing technology and hypoglycaemia in type 1 diabetes: a multicentre, non-masked, randomized controlled trial. Lancet 2016; 388:2254-2263.
  14. Paris I, et al: The new FreeStyle libre flash glucose monitoring system improves the glycaemic control in a cohort of people with type 1 diabetes followed in real-life conditions over a period of one year. Endocrinol Diabetes Metab 2018;1:e00023.
  15. Charleer S, et al: Quality of life and glucose control after 1 year of nationwide reimbursement of intermittently scanned continuous glucose monitoring in adults living with type 1 diabetes (FUTURE): a prospective observational real-world cohort study. Diabetes Care 2020; 43: 389-397.
  16. Cowart K, Updike W, Bullers K: Systematic review of randomized controlled trials evaluating glycemic efficacy and patient satisfaction of intermittent-scanned continuous glucose monitoring in patients with diabetes. Diabetes Technol Ther 2020; 22: 337-345.
  17. Castellana M, et al: Efficacy and safety of flash glucose monitoring in patients with type 1 and type 2 diabetes: a systematic review and meta-analysis. BMJ Open Diabetes Res Care 2020; 8: e001092.
  18. Evans M, et al: The impact of flash glucose monitoring on glycaemic control as measured by HbA1c: a meta-analysis of clinical trials and real-world observational studies. Diabetes Ther 2020; 11: 83-95.
  19. Yoo HJ, 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. Ehrhardt NM, et al: 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.
  21. Beck RW, et al: 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.
  22. Martens T, 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: 2262-2272.
  23. Haak T, et al: Flash glucose-sensing technology as a replacement for blood glucose monitoring for the management of insulin-treated type 2 diabetes: a multicenter, open-label randomized controlled trial. Diabetes Ther 2017; 8: 55-73.
  24. Yaron M, et al: Effect of flash glucose monitoring technology on glycemic control and treatment satisfaction in patients with type 2 diabetes. Diabetes Care 2019; 42: 1178-1184.
  25. Ridder F de, den Brinker M, Block C de: The road from intermittently scanned continuous glucose monitoring to hybrid closed-loop systems. Part B: Results from randomized controlled trials. Ther Adv Endocrinol Metab 2019; 10: 2042018819871903.
  26. “S3 guideline Diagnostics, therapy and follow-up of diabetes mellitus in childhood and adolescence, AWMF register number: 057-016”, version 4, German Diabetes Association (DDG), 2023.
  27. Laffel LM, et al: 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.
  28. Wong JC, et al: T1D Exchange Clinic Network. Real-time continuous glucose monitoring among participants in the T1D Exchange clinic registry. Diabetes Care 2014; 37: 2702-2709.
  29. Foster NC, et al: T1D Exchange Clinic Network. Continuous glucose monitoring in patients with type 1 diabetes using insulin injections. Diabetes Care 2016;39: e81-e82
  30. Mauras N, et al: Diabetes Research in Children Network (DirecNet) Study Group. A randomized clinical trial to assess the efficacy and safety of real-time continuous glucose monitoring in the management of type 1 diabetes in young children aged 4 to <10 years. Diabetes Care 2012; 35: 204-210.
  31. Tsalikian E, et al: Diabetes Research in Children Network Study Group. Feasibility of prolonged continuous glucose monitoring in toddlers with type 1 diabetes. Pediatr Diabetes 2012; 13: 301-307.
  32. Pintus D, Ng SM: Freestyle libre flash glucose monitoring improves patient quality of life measures in children with type 1 diabetes mellitus (T1DM) with appropriate provision of education and support by healthcare professionals. Diabetes Metab Syndr 2019; 13: 2923-2926.
  33. Vergier J, et al: Evaluation of flash glucose monitoring after long-term use: a pediatric survey. Prim Care Diabetes 2019; 13: 63-70.
  34. Landau Z, et al: Use of flash glucose-sensing technology (FreeStyle Libre) in youth with type 1 diabetes: aWeSoMe study group real-life observational experience. Acta Diabetol 2018; 55: 1303-1310.
  35. Deja G, et al: The usefulness of the Flashtyle Libre system in glycemic control in children with type 1 diabetes during summer camp. Pediatr Endocrinol Diabetes Metab 2018; 24: 11-19.
  36. Feig DS, et al: CONCEPTT Collaborative Group. Continuous Glucose Monitoring in Pregnant Women with Type 1 Diabetes (CONCEPTT): a multicentre international randomized controlled trial. Lancet 2017; 390: 2347-2359.
  37. Wei Q, et al: Effect of a CGMS and SMBG on maternal and neonatal outcomes in gestational diabetes mellitus: a randomized controlled trial. Sci Rep 2016;6: 19920.

FAMILY PHYSICIAN PRACTICE 2024; 19(2): 21-22

Autoren
  • Mirjam Peter, M.Sc.
Publikation
  • HAUSARZT PRAXIS
Related Topics
You May Also Like