There is a reasonable explanation for the FAA here..

http://www.aviationmedicine.com/diabetes.htm


At 19:12 07 September 2003, Peter Seddon wrote:
UK

The new NPPL med reqs are less stringent than a JAR
PPL

Peter S
DLA

'Al' wrote in message
...
er where in the world are you?

Al
'242' wrote in message
...
I have heard that it is not possible to obtain a
pilot's license if
afflicted with insulin-dependent diabetes. Is this,
indeed, the case?
Please advise. Thank you.