I've used glucosamine (usually 750-1000mg capsules) combined with chondroitin for many years for knee joint pain, and haven't been aware of any adverse effects on glucose levels since I've been diabetic. However since I started taking this years before I became diabetic, I have no idea whart my levels would be without it, though they are near normal now. I'd suspect though that they may be worse if I wasn't taking it as my kness would be blooming painful and that would most likely have adverse effects...
Robbity