Neuro-cognitive performance in children with type 1 diabetes--a meta-analysis.

Objective: To conduct meta-analyses of neuropsychological performance in young people with type 1 diabetes.

Methods: Meta-analysis of 24 studies. Studies published between 1980 and 2005 were identified. The inclusion criteria were: young people who were < or =19 years of age with type 1 diabetes, a case-control design and standardized neuropsychological tests of seven cognitive domains.

Results: Diabetes was statistically associated with poorer performance on visuospatial ability (d = -0.29), motor speed (d = -0.26) and writing (d = -0.28), on sustained attention (d = -0.21) and reading (d = -0.23). Smaller effects were identified on full IQ (d = -0.14), on performance (d = -0.18) and verbal IQ (d = -0.15). Severe hypoglycemia was linked to deficits in short-term verbal memory (d = -0.14; Confidence Interval: -0.318, 0.024; p =.04).

Conclusions: This meta-analysis indicates that children with type 1 diabetes have mild cognitive impairments and subtly reduced overall intellectual functioning.