A population-based study of risk factors for severe hypoglycaemia in a contemporary cohort of childhood-onset type 1 diabetes

Diabetologia, Jul 2013

Aims/hypothesis Severe hypoglycaemia is a major barrier to optimising glycaemic control. Recent changes in therapy, however, may have altered the epidemiology of severe hypoglycaemia and its associated risk factors. The aim of this study was to examine the incidence rates and risk factors associated with severe hypoglycaemia in a contemporary cohort of children and adolescents with type 1 diabetes. Methods Subjects were identified from a population-based register containing data on >99% of patients (<16 years of age) who were being treated for type 1 diabetes in Western Australia. Patients attend the clinic approximately every 3 months, where data pertaining to diabetes management, demographics and complications including hypoglycaemia are prospectively recorded. A severe hypoglycaemic event was defined as an episode of coma or convulsion associated with hypoglycaemia. Risk factors assessed included age, duration of diabetes, glycaemic control, sex, insulin therapy, socioeconomic status and calendar year. Results Clinical visit data from 1,770 patients, providing 8,214 patient-years of data between 2000 and 2011 were analysed. During follow-up, 841 episodes of severe hypoglycaemia were observed. No difference in risk of severe hypoglycaemia was observed between age groups. Good glycaemic control (HbA1c <7% [53 mmol/mol]) compared with the cohort average (HbA1c 8–9% [64–75 mmol/mol]) was not associated with an increased risk of severe hypoglycaemia. When compared with patients on injection regimens, subjects aged 12–18 years on pump therapy were at reduced risk of severe hypoglycaemia (incidence risk ratio 0.6; 95% CI 0.4, 0.9). Conclusions/interpretation In this population-based sample of children and adolescents with type 1 diabetes, contemporary therapy is associated with a changed pattern and incidence of severe hypoglycaemia.

A PDF file should load here. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a PDF plug-in installed and enabled in your browser.

Alternatively, you can download the file locally and open with any standalone PDF reader:

https://link.springer.com/content/pdf/10.1007%2Fs00125-013-2982-1.pdf

A population-based study of risk factors for severe hypoglycaemia in a contemporary cohort of childhood-onset type 1 diabetes

Matthew N. Cooper Susan M. O'Connell Elizabeth A. Davis Timothy W. Jones 0 ) Telethon Institute for Child Health Research, Centre for Child Health Research, The University of Western Australia , Perth, WA , Australia Aims/hypothesis Severe hypoglycaemia is a major barrier to optimising glycaemic control. Recent changes in therapy, however, may have altered the epidemiology of severe hypoglycaemia and its associated risk factors. The aim of this study was to examine the incidence rates and risk factors associated with severe hypoglycaemia in a contemporary cohort of children and adolescents with type 1 diabetes. Methods Subjects were identified from a population-based register containing data on >99% of patients (<16 years of age) who were being treated for type 1 diabetes in Western Australia. Patients attend the clinic approximately every 3 months, where data pertaining to diabetes management, demographics and complications including hypoglycaemia are prospectively recorded. A severe hypoglycaemic event was defined as an episode of coma or convulsion associated with hypoglycaemia. Risk factors assessed included age, duration of diabetes, glycaemic control, sex, insulin therapy, socioeconomic status and calendar year. - Abbreviations BD Twice-daily insulin injection CSII Continuous subcutaneous insulin infusion IRR Incidence risk ratio MDI Multiple-daily insulin injection SEIFA Index of relative socioeconomic disadvantage The threat of hypoglycaemia as a consequence of insulin treatment is the single most important barrier to optimising glycaemic control in type 1 diabetes [1, 2]. The major challenge for clinicians treating children and adolescents is to optimise glycaemic control whilst avoiding hypoglycaemia. Fear of hypoglycaemia can have a negative impact on quality of life [3, 4] and metabolic control [5, 6], which can be detrimental to achieving improved glycaemic control. The Diabetes Control and Complications Trial showed that intensive management resulted in a significant increase in episodes of severe hypoglycaemia [7, 8]. Similarly, in the early 1990s, at our centre, increased emphasis on optimising glycaemic control was paralleled by an increase in the rate of severe hypoglycaemia, particularly in younger children (<6 years) [1, 9]. In three previous publications we have reported rates of, and associations with, severe hypoglycaemia in a population-based sample of children and adolescents with type 1 diabetes [1, 3, 10]. In those reports, we found that an increased risk of severe hypoglycaemia was associated with younger age (<6 years), lower HbA1c, higher insulin dose, male sex, longer duration of diabetes and lower parental socioeconomic status. Increasingly, evidence is emerging that rates of severe hypoglycaemia may be reducing [3, 11, 12]. This may have resulted from improvements in therapy [13], suggesting that re-evaluation of the factors associated with severe events may be required. As a follow-up to the previously published analysis [1, 10] and a subsequent update of rates of severe hypoglycaemia [3], our objectives for this study were to characterise the current epidemiology of, and risk factors for, severe hypoglycaemia in a contemporary child and adolescent population-based cohort. All children and adolescents with type 1 diabetes aged 18 years attending the diabetes clinic at Princess Margaret Hospital for Children from 2000 to 2011 inclusive participated in the study. The Department of Endocrinology and Diabetes is the only paediatric referral centre for diabetes in the state of Western Australia (2012 population 2.4 million [14]). The case ascertainment for this centre has previously been shown to be 99.9% for children diagnosed at <16 years of age [15]. Consent for data to be entered into the database was obtained from all parents or guardians, and data collection was approved by the institutions ethics committee. All patients attending the centre are managed by a multidisciplinary diabetes care team, which includes a paediatric diabetologist, diabetes nurse educator, dietitian, social worker and psychologist. Education for recognition and treatment of hypoglycaemia, and preventive measures for special circumstances such as participation in exercise, is routine. The patients and their family were advised to keep a logbook of blood glucose levels and insulin doses, and to record all adverse or atypical events such as episodes of hypoglycaemia or illness. They were taught to obtain a blood glucose level, if possible, to confirm hypoglycaemia. They were seen in the clinic approximately every 3 months, and data on all diabetes outcomes including hypoglycaemic events and treatment types were prospectively recorded in the Western Australian Childhood Diabetes Database, as has been described in our past reports. Subjects exited the study upon turning 18 years, leaving the state permanently or if 12 months had lapsed following their last clinic visit. HbA1c was determined at each (...truncated)


This is a preview of a remote PDF: https://link.springer.com/content/pdf/10.1007%2Fs00125-013-2982-1.pdf

Matthew N. Cooper, Susan M. O’Connell, Elizabeth A. Davis, Timothy W. Jones. A population-based study of risk factors for severe hypoglycaemia in a contemporary cohort of childhood-onset type 1 diabetes, Diabetologia, 2013, pp. 2164-2170, Volume 56, Issue 10, DOI: 10.1007/s00125-013-2982-1