Hi Ben,
My Sister and Father are both Type 1 Diabetics. Although neither are climbers my Sister has a particularly active lifestyle. The only effect it has is on management of diet, insulin and when and how much to eat. She in fact is now living in Nepal (again not as a climber) and the main issue there is supply of insulin and blood sugar monitoring stuff.
So although I can't say definitively how it would effect climbing id say that, with monitoring, you will be ok once you get into the routine.
All the best
Steve |