Child and parental mental ability and glycaemic control in children with Type 1 diabetes.

AIMS: Many psycho-social factors can affect the glycaemic control of children with Type 1 diabetes, but the influence of the intelligence of the child and their parents has not been reported. METHODS: Seventy-eight children and adolescents with Type 1 diabetes and their mothers performed standardized tests to assess psychometric intelligence. The children were aged (median (range)) 12.0 (5-17) years with duration of diabetes 5.0 (1.0-13.0) years and required an insulin dose of (mean +/- SD) 1.0 +/- 0.3 U/kg per day. The children completed the Wide Range Achievement Test 3 reading test (WRAT3) and Raven's Standard Progressive Matrices (RSPM). A mean annual HbA1c was calculated for each subject (8.6 +/- 1.4%). The mothers performed the National Adult Reading Test (NART) and provided details of the occupation of the main wage-earner in the family from which social class (SC) was derived. RESULTS: The HbA1c of the child correlated with their age (r = 0.26, P = 0.02), SC (Kendall's rank correlation, tau = 0.17, P = 0.03) and with the NART error score of their mother (r = 0.28, P = 0.01), but no correlation was observed with the child's WRAT3 or RSPM score. Stepwise regression revealed that age and NART error score were the strongest independent determinants of glycaemic control (total adjusted r2 = 0.117). CONCLUSIONS: Parental intelligence appears to have a significant influence on the glycaemic control of a child with Type 1 diabetes, accounting for 7.6% of the reliable variance in HbA1c.