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. 2024 Dec;15(12):2489-2498.
doi: 10.1007/s13300-024-01648-w. Epub 2024 Oct 23.

The Relation of Diabetes Complications to a New Interpretation of Glycaemic Variability from Continuous Glucose Monitoring in People with Type 1 Diabetes

Adrian H Heald  1   2 , Mike Stedman  3 , John Warner Levy  4 , Lleyton Belston  4 , Angela Paisley  5 , Reena Patel  6 , Alison White  7 , Edward Jude  8 , JMartin Gibson  4   5 , Hellena Habte-Asres  9 , Martin Whyte  10 , Angus Forbes  11
Affiliations

The Relation of Diabetes Complications to a New Interpretation of Glycaemic Variability from Continuous Glucose Monitoring in People with Type 1 Diabetes

Adrian H Heald et al. Diabetes Ther. 2024 Dec.

Abstract

Introduction: Microvascular and macrovascular complications in type 1 diabetes (T1D) may be linked to endothelial stress due to glycaemic variability. Continuous glucose monitoring systems (CGMs) provide new opportunities to quantify this variability, utilising the amplitude of glucose change summated over time. The aim of this study was to examine whether this determination of glucose variability (GV) is associated with microvascular clinical sequelae.

Methods: Continuous glucose monitoring values were downloaded for 89 type 1 diabetes mellitus (T1D) individuals for up to 18 months from 2021 to 2023. Data for patient demographics was also taken from the patient record which included Sex, Date of Birth, and Date of Diagnosis. The recorded laboratory glycated haemoglobin (HbA1c) test results were also recorded. The glucose management index (GMI) was calculated from average glucose readings for 18 months using the formula GMI (%) = (0.82-(Average glucose/100)). This was then adjusted to give GMI (mmol/mol) = 10.929 * (GMI (%) - 2.15). Average Glucose Fluctuation (AGF) was calculated by adding up the total absolute change value between all recorded results over 18 months and dividing by the number of results minus one. The % Above Critical Threshold (ACT) was calculated by summing the total number of occurrences for each result value. A cumulative 95% limit was then applied to identify the glucose value that only 5% of results exceeded in the overall population. Using this value, we estimated the percentage of total tests that were above the Critical Threshold (ACT).

Results: Results for the 89 individuals (44 men and 45 women) were analysed over 18 months. The mean age of participants was 43 years and the mean duration of diabetes was 18 years. A total of 3.22 million readings were analysed, giving an average of 10.3 mmol/L blood glucose. Those with the largest change in glucose from reading to reading, summated over time, showed the greatest change in eGFR of 3.12 ml/min/1.73 m2 (p = 0.007). People with a higher proportion of glucose readings > 18 mmol/L showed a fall in eGFR of 2.8 ml/min/1.73 m2 (p = 0.009) and experienced higher rates of sight-threatening retinopathy (44% of these individuals) (p = 0.01) as did 39% of individuals in the highest tertile of glucose levels (p = 0.008).

Conclusion: Those individuals with T1D in the highest tertile of reading-to-reading glucose change showed the greatest change in eGFR. Those with a higher proportion of glucose readings > 18 mmol/L also showed a fall in eGFR and experienced higher rates of sight-threatening retinopathy, as did people with higher mean glucose. Discussions with T1D individuals could reflect on how the percentage recorded glucose above a critical level and degree of change in glucose are important in avoiding future tissue complications.

Keywords: Complications; Continuous glucose monitoring; Glycaemic variability; Hyperglycaemia; Type 1 diabetes.

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Conflict of interest statement

Declarations Conflict of interest Adrian H Heald, Mike Stedman, John Warner Levy, Lleyton Belston, Angela Paisley, Reena Patel, Alison White, Edward Jude, J Martin Gibson, Hellena Habte-Asres, Martin Whyte and Angus Forbes have nothing to declare. Ethical Approval All participants were attending the clinic of one of the authors (Adrian H Heald). The FreeStyle Libre data are available in its entirety as part of their usual care for analysis by the clinical team. All patients were given the option to opt out of their data being analysed. Such data analysis in relation to clinical care is acceptable under UK research ethics guidance. Patients whose data were analysed were kept fully informed, in accordance with the UK guidance at https://digital.nhs.uk/services/national-data-opt-out/understanding-the-national-data-opt-out/protecting-patient-data. All data were full anonymised prior to analysis.

References

    1. Deckert T, Poulsen JE, Larsen M. Prognosis of diabetics with diabetes onset before the age of thirty-one. Survival, causes of death, and complications. Diabetologia. 1978;14(6):363–70. - PubMed
    1. Diabetes Control and Complications Trial Research Group; Nathan DM, Genuth S, et al. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin dependent diabetes mellitus. N Engl J Med. 1993;329(14):977–86. - PubMed
    1. Nathan DM, Cleary PA, Backlund JY, et al. Intensive diabetes treatment and cardiovascular disease in patients with type 1 diabetes. N Engl J Med. 2005;353(25):2643–53. - PMC - PubMed
    1. Beck RW, Connor CG, Mullen DM, Wesley DM, Bergenstal RM. The fallacy of average: how using HbA1c alone to assess glycemic control can be misleading. Diabetes Care. 2017;40:994–9. - PMC - PubMed
    1. Heinemann L, Freckmann G, Müller-Wieland D, Kellerer M. Critical reappraisal of the time-in-range: alternative or useful addition to glycated hemoglobin? J Diabetes Sci Technol. 2020;14(5):922–7. - PMC - PubMed

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