I frankly beleive that frequent testing is the real root of good control.
So as far as impotence
is concerned, this is caused by nerve damage, and
keeping good glucose control will protect you from this complication.
A case in point here... a year or so ago, I unfortunately caught the flu, having not been able to get a flu shot until I actually caught the flu. I was ill for about a month, and glucose levels were elevated above my usual very tight control.