Impaired awareness of hypoglycaemia: Prevalence and associated factors before and after FreeStyle Libre use in the Association of British Clinical Diabetologists audit

Abstract

BACKGROUNDFreeStyle Libre (FSL), intermittently scanned continuous glucose monitoring (isCGM), is associated with less biochemical hypoglycaemia in people with diabetes, lower HbA1c and diabetes-related distress. 1 Impaired awareness of hypoglycaemia (IAH), which affects 18%-33% of people with type 1 diabetes, 2 is the reduced ability to detect the symptoms of hypoglycaemia and is associated with a 6-fold increased risk of severe hypoglycaemia (SH). 3 Many of the studies of CGM have shown a reduction in rates of hypoglycaemia but have not shown restoration of awareness. [4][5][6] There are limited nationwide data investigating the prevalence of IAH, complete loss of awareness of hypoglycaemia and SH. We have recently shown the use of FSL is associated with improvement in awareness of hypoglycaemia, 1 however, some studies have shown no benefit of FSL on IAH. 5,7 It is therefore important to identify the factors associated with improvement in IAH with the use of FSL. | METHODSThis observational study analysed data collated from November 2017 to August 2021 as part of the nationwide Association of British Clinical Diabetologists (ABCD) audit on FSL. 8 The methodology of the nationwide audit has been described in an article 1 reporting previous results of the audit. In this audit, people with diabetes were using FreeStyle Libre or FreeStyle Libre 2.The Gold score was used to assess awareness of hypoglycaemia. 9 A score of 4 or higher indicates IAH and 7 indicates a complete loss of awareness. 9 Diabetes-related distress was measured using the twoitem diabetes distress screening tool (DDS2). 10 An average of the two questions of the DDS2 scale was calculated. A score of 3 or higher was classified as 'moderate diabetes-related distress' and an average score of less than 3 was considered as 'low distress'.

Prevalence of impaired awareness of hypoglycaemia in people with diabetes mellitus: A systematic review and meta‐analysis from 21 countries and regions

“…The result presented here supports that the duration of diabetes and HbAc1 are significant predictors. The previous works demonstrated that individuals' subjective perception of hypoglycaemia and the intensity of their autonomous symptoms (especially trembling, hunger and sweating) progressively diminished with the duration of diabetes 33,34 . Specifically, the prevalence of IAH in people with diabetes increased from 3.0% for the duration of 2–9 years to 28.0% for the duration of at least 30 years 33 .…”

“…The previous works demonstrated that individuals' subjective perception of hypoglycaemia and the intensity of their autonomous symptoms (especially trembling, hunger and sweating) progressively diminished with the duration of diabetes. 33,34 Specifically, the prevalence of IAH in people with diabetes increased from 3.0% for the duration of 2-9 years to 28.0% for the duration of at least 30 years. 33 The group of patients with a longer duration of diabetes merits priority attention in future research and clinical practice.…”

Impaired awareness of hypoglycaemia

“…CGM and intermittent retrospectively monitored CGM (Flash) with alarms are of proven benefit, the former in people with IAH and/or a history of severe hypoglycaemia, 21 the latter in a less selected population. 22 Replacing intermittent injections of insulin with continuous subcutaneous insulin infusion (pump) therapy also has older evidence to show benefit in reducing severe hypoglycaemia, 23 and the automated regulation of insulin delivery by pumps responding to data from linked CGM systems, including hybrid closed-loop systems, shows evidence of benefit. 24 Useful effects have been observed in populations at risk, 25,26 although protection from severe hypoglycaemia has not been seen in all studies, 27 and some have not focused on highrisk populations.…”

Clinical features of type 1 diabetes in older adults and the impact of intermittently scanned continuous glucose monitoring: An Association of British Clinical Diabetologists (ABCD) study

“…In recent years, intermittently scanned continuous glucose monitoring (isCGM) has emerged as a valuable tool for glycaemic management in T1D. [6][7][8][9][10][11] isCGM allows for real-time monitoring of glucose levels through a small sensor inserted under the skin, providing glucose readings at regular intervals without the need for frequent fingerstick blood glucose monitoring. isCGM has been shown to improve glycaemic control, reduce hypoglycaemic events, and enhance quality of life in individuals with T1D.…”