Assuming you're aged between 16 and 65, you'd only be able to claim PIP, which has replaced DLA for new claimants of "working age". You'd need to show that you have problems with some of 10 daily living activies and / or problems with making a journey / mobility. It's very unlikely that and adult with simple type 1 diabetes, in the absence of complications, severe hypo unawarenes etc could qualify for any award of PIP.