Height at diagnosis of diabetes in children: a study in identical twins.

The height at diagnosis of 16 insulin dependent diabetics aged under 19 was compared with that of their unaffected identical cotwins measured at the same time. In eight pairs the diabetic was shorter, and in the remainder the cotwins were the same height. In those diabetics who were shorter than their cotwins at diagnosis the average period of growth delay before diagnosis was at least 35 weeks; by contrast, the mean duration of symptoms was only six weeks. No cause for the growth delay other than the diabetes was known in any of the twins. These findings show that the onset of insulin dependent diabetes may be a slow process, with growth delay occurring several months before symptoms appear.