Many of us in the field of diabetes care are now very used to the CDE (Certified Diabetes Educator) credential. It's a worthy addition to the alphabet soup that health professionals stick after their names to indicate what training they've completed, so you might see someone who gives their name as "Jane Jones, RN, CDE" or "Sarah Jones, MD, CDE" or "Jessie Jones, RD, CDE" (or James, Sam, and John -- not trying to be sexist here).
The CDE credential was first developed in the mid-1980s by the American Association of Diabetes Educators, back when I was president of AADE. AADE was then working together with the American Diabetes Association in setting up a process for recognition of diabetes programs, and simultaneously wanted to set up a program for recognition of individual health care professionals who were diabetes educators.
We decided that a separate organization (which we named the NCBDE, the National Certification Board for Diabetes Educators) would be the best route to go. Initially, the NCBDE functioned as a subsidiary of AADE, but later it grew to the point of complete independence from AADE.
We also decided that the CDE credential would be multidisciplinary. That is, not just a credential for nurses, or for physicians, or dietitians, but for any healthcare professional who had sufficient training in their field, and who could document that they were doing diabetes education. A certification exam was set up, with questions involving principles of education, as well as diabetes medications, dietary principles, nursing care, and psychosocial aspects of living with chronic disease.
Occasionally, I get an e-mail request from a health professional who says they are primarily in some other field (e.g., critical care nursing), but that they do now-and-then teach diabetes patients. They wonder if they would be eligible for the CDE credentialing process: the answer is no; per the NCBDE website, "The Certification Examination for Diabetes Educators ("Examination") is designed and intended solely for health care professionals who have defined roles as diabetes educators, not for those who may perform some diabetes related functions as part of or in the course of other usual and customary duties."
Another aspect of the CDE credential is that it needs renewing every five years. Renewal means continued practice as a diabetes educator, and passing an exam or documenting continuing education activities. So, I had the CDE credential for several cycles of renewals, but when I left office practice, I let my CDE certification lapse. I guess I could have continued to renew (by doing the paperwork and passing the written exam that was required in those days).
Finally, the CDE credential is aimed primarily at US healthcare professionals. Indeed, it's required that the continuing diabetes education practice "take place in the United States or its territories."
There's also a Canadian version of the CDE: the Canadian Diabetes Educator Certification Board (CDECB). As with the US NCBDE, the CDECB is independent and separate from all other diabetes-related organizations and associations. I'm unaware of any other countries with CDE organizations; if you are, please comment below, and include a hyperlink to their website(s).