Article

The Effects of Type 1 Diabetes on Cognitive Performance A meta-analysis

Department of Neurology, University Medical Center, Utrecht, the Netherlands.
Diabetes Care (Impact Factor: 8.57). 04/2005; 28(3):726-35. DOI: 10.2337/diacare.28.3.726
Source: PubMed

ABSTRACT To investigate the exact nature and magnitude of cognitive impairments in patients with type 1 diabetes and the possible association with other disease variables, such as recurrent episodes of hypoglycemia and metabolic control.
MedLine and PsycLit search engines were used to identify studies on cognitive performance in patients with type 1 diabetes. Effect sizes (Cohen's d), which are the standardized differences between the experimental and the control group, were calculated. In the meta-analysis, a combined d value was calculated, expressing the magnitude of associations across studies.
A total of 33 studies were identified that met the inclusion criteria. Compared with nondiabetic control subjects, the type 1 diabetic group demonstrated a significantly lowered performance on the following cognitive domains: intelligence (d = -0.7), speed of information processing (d = -0.3), psychomotor efficiency (d = -0.6), visual (d = -0.4) and sustained attention (d = -0.3), cognitive flexibility (d = -0.5), and visual perception (d = -0.4). Lowered cognitive performance in diabetic patients appeared to be associated with the presence of microvascular complications but not with the occurrence of severe hypoglycemic episodes or with poor metabolic control.
In patients with type 1 diabetes, cognitive dysfunction is characterized by a slowing of mental speed and a diminished mental flexibility, whereas learning and memory are spared.The magnitude of the cognitive deficits is mild to moderate, but even mild forms of cognitive dysfunction might hamper everyday activities since they can be expected to present problems in more demanding situations.

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Available from: Augustina M A Brands, Aug 14, 2015
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    • "Consequently, we aimed to explore neurofunctional activation in young T1D patients with normal intelligence and without diabetic complications versus healthy control participants during a visuospatial working memory task. If brain metabolism has been altered in these patients, as has been suggested [17] [32], then we would expect that the blood oxygen level-dependent (BOLD) fMRI activation response could reflect differences in cognitive processing between the two groups, especially considering that working memory is one of the cognitive domains [4] in these patients [3] [23] [33] that has most often been shown to be affected, and is most frequently explored. "
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