The intellectual development of 33 children born to 33 diabetic Japanese mothers (ODM) was compared to that of 34 control offspring of non-diabetics delivered at Kurume University Hospital, Fukuoka, Japan, between 1987 and 1989. Intelligence scores on the Tanaka-Binet test were significantly lower in the ODMs at 3 years of age than in controls. Maternal age and infant IQ were inversely correlated in ODMs but not in controls. [1]
COMMENT. Infants of diabetic mothers may be at risk for impaired intellectual development, and especially infants born to older mothers. The difference in IQ between offspring of diabetics and non-diabetics was not associated with maternal toxemia or postnatal hyperbilirubinemia or hypoglycemia. A longer period of follow-up was considered important in determining the final cognitive outcome of these children.
Severe hypoglycemia and cognitive impairment in diabetes is reviewed and the link is considered not proven in a report from the Department of Psychology, University of Edinburgh, and Department of Diabetes, Royal Infirmary of Edinburgh [2]. Among young adults with insulin dependent diabetes, recurrent episodes of severe hypoglycemia over a 5 to 15 year period have either a mild or negligible effect on cerebral function, except for a few subjects who are unusually vulnerable and suffer permanent brain damage. While strict glycemic control delays onset of retinopathy, nephropathy, and neuropathy, it is associated with a threefold increase in severe hypoglycemia.