Impact of improved glycaemic control on rates of hypoglycaemia in insulin dependent diabetes mellitus

Abstract

Increased emphasis on strict glycaemic control of insulin dependent diabetes mellitus (IDDM) in young patients may be expected to cause increases in rates of significant hypoglycaemia. To evaluate whether this is the case for a large population based sample of IDDM children and adolescents rates of severe (coma, convulsion) and moderate (requiring assistance for treatment) hypoglycaemia were studied prospectively over a four year period.A total of 709 patients were studied yielding 2027 patient years of data (mean (SD) age: 12.3 (4.4); range 0-18 years, duration IDDM: 4.9 (3.8) years). Details of hypoglycaemia were recorded at clinic visits every three months when glycated haemoglobin (HbA1 c ) was also measured.Overall the incidence of severe hypoglycaemia was 7.8 and moderate was 15.4 episodes/100 patient years. Over the four years mean (SD) clinic HbA1 c steadily fell from 10.2 (1.6)% in 1992 to 8.8 (1.5)% in 1995. In parallel with this there was a dramatic increase in the rate of hypoglycaemia, especially in the fourth year of the study, when severe hypoglycaemia increased from 4.8 to 15.6 episodes/100 patient years. This increase was particularly marked in younger children (<6 years) in whom severe hypoglycaemia increased from 14.9 to 42.1 episodes/100 patient years in 1995.It is concluded that attempts to achieve improved metabolic control must be accompanied by eVorts to minimise the eVects of significant hypoglycaemia, particularly in the younger age group. (Arch Dis Child 1998;78:111-115) Keywords: hypoglycaemia; insulin dependent diabetes mellitus; glycaemic control Hypoglycaemia is the most common acute complication of the treatment of insulin dependent diabetes mellitus (IDDM) and its occurrence often restricts attempts to improve glycaemic control. This is particularly critical for younger patients who may be even more susceptible to severe hypoglycaemia 1 as a result of the interaction of both physiological and behavioural factors. A number of reports have described the incidence and clinical factors associated with significant hypoglycaemia in childhood but many of these have become outdated with recent changes to management goals and practices.2-5 For example, the greater emphasis on improved metabolic control and intensified treatment after the release of the Diabetes Control and Complications Trial (DCCT) results is likely to have altered the epidemiology of this acute complication of treatment. 6 We have recently reported results of a study performed over a three year period in which we found a high incidence of significant hypoglycaemia in children and adolescents. 7 Episodes were rare in the first year from diagnosis but were more frequent in children aged <6 years and in those with lower glycated haemoglobin (HbA1 c ). We now report a continuation of the same study, now completed over four years, and analysed to determine the relationship between glycaemic control and rates of hypoglycaemia. Although the association between lower HbA1 c and the incidence of severe hypoglycaemia h...

Care of Children and Adolescents With Type 1 Diabetes

“…Hypoglycemia is more frequent in children with lower A1C levels, a prior history of severe hypoglycemia, and higher insulin doses and in younger children (122). In addition, longer duration of diabetes and male sex have been associated with increased risk of hypoglycemia.…”

Hypoglycemic neuronal death is triggered by glucose reperfusion and activation of neuronal NADPH oxidase

“…Insulin and sulfonylurea therapy for diabetes mellitus carries the risk of hypoglycemic brain injury, and this risk is a major impediment to optimal glucose regulation in diabetic patients (1,2). Depending upon its severity, hypoglycemia (HG) can cause irritability, impaired concentration, focal neurological deficits, seizures, coma, and, with profound HG, neuronal death (3)(4)(5).…”

The Impact of a Decade of Changing Treatment on Rates of Severe Hypoglycemia in a Population-Based Cohort of Children With Type 1 Diabetes

“…More recent reports have used a prospective study design, an approach stimulated by the DCCT experience and protocols (1). This approach, combined with careful definition of hypoglycemic events and well-described subject populations, has removed some of the limitations of crosssectional studies (5)(6)(7)(8).…”