excessive sweating can be a symptom of Autonomic Neuropathy ( one of the O'Pathy sisters).
The bodily functions that work automatically ( without you have to consciously do them e.g heart beat, breathing, sphincters opening/closing) are sent skew whiff by high (?) bgs....
Quote ...
"Sweating
Autonomic neuropathy can affect the nerves that control sweating. Sometimes, nerve damage interferes with the activity of the sweat glands, making it difficult for the body to regulate its temperature. Other times, the result can be profuse sweating at night or while eating (gustatory sweating). "
http://www.wrongdiagnosis.com/a/autonomic_neuropathy/subtypes.htm