According to this Medline Plus article as of 2010 approximately 9% of Americans have diabetes mellitus (21 million adults) and 12% of them have pre-diabetes. The rise in diabetes is in conjunction to the rising obesity rate which is estimated to be 32% of the U.S. population in 2010.
The FMCSA States:
The driver with diabetes mellitus who does not use insulin is eligible for certification, unless the driver also has a disqualifying complication, co-morbidity, or fails to meet one or more of the other standards for qualification.
For drivers who use insulin please see previous post at dotmedicalexaminerblog.com for information on the Federal Diabetes Exemption Program. When a driver comes in for a DOT medical certification examination, assessing the risk for severe hypoglycemic episode is the most critical concern in a person with diabetes. For drivers using oral hypoglycemic medications, although no waiting period is required, the driver should not be certified until the treatment has been found to be adequate, safe, effective and stable. Maximum certification recommended is for 1 year.
For more information on diabetes, see the following link which provides an overview of diabetes, a diabetes guide book, and an interactive tutorial.