Impaired intellectual development in children with Type I diabetes: association with HbA 1 c , age at diagnosis and sex

Abstract

Treatment, and even more so, care of children with Type I (insulin-dependent) diabetes mellitus is a difficult and demanding task for parents as well as for health professionals. Aiming for good metabolic control is often hindered by the dynamics of the disease, an insufficiency of insulin therapy, the impossibility of an exact control of carbohydrate intake and the irregularities of daily life. The knowledge of the risk of long-term vascular complications and the permanent uncertainty of threatening hypoglycaemia as an immediate complication, is a great burden for the responsible paediatric diabetologist and thus narrows his or her therapeutic possibilities.There is now clear evidence that poor long-term metabolic control is the crucial factor for developing late vascular complications [1 ± 3]. In addition, there is growing evidence that the quality of metabolic control even during pre-pubertal years greatly influences Diabetologia (2002) Abstract Aims/hypothesis. Good metabolic control in diabetic children is already crucial before puberty to prevent diabetic complications later in life. However, tight metabolic control could increase the risk of severe hypoglycaemia, which might be responsible for impaired intellectual performance later in life. The purpose of this prospective longitudinal study was to evaluate the relevance of long-term metabolic control and hypoglycaemia possibly affecting the intellectual development of young children with Type I (insulin-dependent) diabetes mellitus.Methods. The intellectual development in 64 diabetic children between the ages of 7 and 16 years was assessed at least four times using the German version of the Hamburg Wechsler intelligence scale for preschool children, Children-Revised and by the ªAdap-tives Intelligenz Diagnostikumº (Adaptive Intelligence Diagnosticum). Data were analysed longitudinally compared with a control group.Results. A significant decline in performance by age 7 and in verbal intelligence quotient between age 7 and 16 years was observed in diabetic boys diagnosed before the age of 6 but not in those diagnosed later and not in diabetic girls. The deterioration of intellectual performance in boys diagnosed at a very young age was not associated with the occurrence of severe hypoglycaemic episodes but was correlated with the degree of metabolic deterioration at diagnosis and with high long-term average of glycated haemoglobin. Conclusion/interpretation. Our study in diabetic children shows that the male sex, diagnosis at a young age, metabolic condition at diagnosis and long-term metabolic control, rather than experienced hypoglycaemic attacks are risk factors for intellectual development. [Diabetologia (2002) 45: 108±114]

The Effects of Type 1 Diabetes on Cognitive Performance

“…We observed that the pattern and severity of cognitive changes in study populations of adult diabetic patients with an average age at diabetes onset Ͻ15 years were comparable to those with an average age at onset above this age. It should be noted, however, that studies that assessed cognition in children with diabetes (which were not included in the present metaanalysis) observed that a very early age at onset (before the age of 5 years) does ap- 29 -31,36,37,39,41), b ϭ (29,30,36,41), c ϭ (4,31,37,39,41), d ϭ (29,36,37,39), e ϭ (29,37,39), f ϭ (30,37,39,41), g ϭ (29,36), h ϭ (4,39,41), i ϭ (29,31,37,39,41), j ϭ (4,29,36,37,39), and k ϭ (29,39) pear to be associated with more severe impairments of cognitive performance (11,46). Our meta-analysis does not support the idea that there are important negative effects from recurrent episodes of severe hypoglycemia on cognitive functioning.…”

Effects of insulin on long-term potentiation in hippocampal slices from diabetic rats

“…These problems are typically thought to result from hypoglycaemic attacks [1,2], which occur more frequently during intensive insulin therapy [3]. Although insulininduced hypoglycaemia could contribute to learning problems [4], one recent prospective study did not find a relationship between severe hypoglycaemic events and cognitive impairment [5], raising the possibility that the diabetic condition alone might adversely affect learning and memory. Experimental evidence supporting an independent effect of diabetes upon brain function comes from studies showing that diabetic rats show memory impairment in the absence of insulin treatment or hypoglycaemia [6].…”

Control metabólico y rendimiento escolar en niños con diabetes tipo 1

“…Los déficits cognitivos más comunes identificados en pacientes con DM1 corresponden al enlentecimiento de la velocidad de procesamiento de información [32][33][34][35] y la disminución en la habilidad psicomotora 32,33,36 . Se han observado otras anomalías, como déficits en la velocidad motriz 34,37,38 , vocabulario 20,36,39 , inteligencia general 40 , formación de la imagen visual 35,40 , atención 35 , examen somato sensorial, potencia motriz 38 , memoria y finalmente en la función ejecutiva 36 . A su vez, investigaciones plantean que tanto la hipoglicemia como la hiperglicemia afectan la velocidad de reacción y cálculos matemáticos, incidiendo de forma directa en la capacidad cognitiva de niños con DM1 con mal control metabólico 24 .En niños que debutan antes de los 5 años con historia de hipoglicemias severas, se ha reportado deficiencias en la inteligencia espacial y memoria de mediano plazo, lo que sugiere que el cerebro en desarrollo podría ser susceptible a la hipoglicemia 41 .…”