A Study on Impaired Awareness of Hypoglycaemia in Type 1 Diabetes Patients in a Tertiary Care Centre in Singapore

Background: This study aims to establish the frequency of severe hypoglycaemia and impaired awareness of hypoglycaemia (IAH) in Type 1 diabetes (T1D) patients in Singapore. We evaluate the utility of the Gold and Clarke scores as screening tools for IAH, and assess the effects of diabetes self-management practices and education in reducing IAH. Methods: This is an observational study of 131 subjects with T1D at a regional hospital, which included review of medical records, self-administered questionnaires and a prospective 4 week period of self-monitoring of blood glucose (SMBG). Results: The frequency of clinically significant hypoglycaemia (blood glucose < 3 mmol/L) during the 4 week period of SMBG was 38.8%, while the frequency of severe hypoglycaemia over the last one year was 22.5%. Based on the Gold score and Clarke score, 28.3% and 24.6% of subjects respectively had IAH. The Clarke score was associated with increased frequency of clinically significant hypoglycaemia, severe hypoglycaemia and hospitalizations for hypoglycaemia. Prior group education, education from a dietitian and education on blood glucose targets were associated with lower Clarke scores, while adjusting insulin doses for blood glucose using an insulin sensitivity factor was associated with lower Gold and Clarke scores. Conclusion: IAH is common in T1D patients in Singapore and is associated with increased risk of severe hypoglycaemia. The Gold and Clarke scores are simple tools which can be routinely administered to identify patients with IAH who might benefit from specific interventions, particularly structured diabetes education, to decrease IAH and its complications.

Clinical approaches to treat impaired awareness of hypoglycaemia

Impaired awareness of hypoglycaemia (IAH) affects between 25% and 30% of all people with type 1 diabetes (T1D) and markedly increases risk of severe hypoglycaemia. This greatly feared complication of T1D impairs quality of life and has a recognised morbidity. People with T1D have an increased propensity to hypoglycaemia as a result of fundamental physiological defects in their ability to respond appropriately to a fall in blood glucose levels. With repeated exposure to low glucose, many then develop a condition referred to as IAH, where there is a reduced ability to perceive the onset of hypoglycaemia and take appropriate corrective action. The management of individuals with IAH relies initially on its identification in the clinic through a detailed exploration of the frequency of hypoglycaemia and an assessment of the individual’s ability to recognise these episodes. In this review article, we will address the clinical strategies that may help in the management of the patient with IAH once identified, who may or may not also suffer from problematic hypoglycaemia. The initial focus is on how to identify such patients and then on the variety of approaches involving educational programmes and technological approaches that may be taken to minimise hypoglycaemia risk. No single approach can be advocated for all patients, and it is the role of the health care professional to identify the clinical strategy that best enables their patient to achieve this goal.