Provided I otherwise qualify and have never sought FAA medical certification, am I authorized to exercise sport pilot privileges on the basis of a current and valid driver�s license if I have a chronic medical condition such as diabetes?

Response by the Federal Air Surgeon
You should consult your private physician to determine whether you have a medical deficiency that would interfere with the safe performance of sport piloting duties. You may exercise sport pilot privileges provided you are in good health, your medical condition is under control, you adhere to your physician�s recommended treatment, and you feel satisfied that you are able to conduct safe flight operations.