CAH and Diabetes are both on chromosome 6 and it is possible to have both (though rare).  I am aware of 2 cases of salt wasting CAH who have developed diabetes in childhood.  Full investigations were carried out.  Was it possible that overtreatment of hydrocortisone for the CAH had caused the diabetes?  However no conclusive evidence was found or any connection between the two conditions.  These patients were just 'unlucky'.  I am withholding my name as I am unable to give any further information without breaking confidentiality regulations.