I agree, it's not possible to make a blanket statement about the MDM level based on just this - you have to look at the full picture of what's in the documentation. Remember too that amount of data reviewed also plays a role. Under the audit tools that use the points system, a single stable chronic problem with minimal or no data would be counted as SF MDM, but these are meant to be guidelines, not hard and fast rules.
I also recommend avoiding the use of MDM as one of the two required elements for established patient visit levels, especially at the lower level visits. I worked for a facility that followed this practice and I came to feel that this can lead to errors and underrepresent physician work. A chronic and complex disease such as DM may support significant history, exam and physician time even if the MDM comes out as SF in the audit tool. That said, if the patient has well-controlled and asymptomatic diabetes with no comorbidities (which would be rare) and all the documentation shows is that provider is looking over the labs and saying come back in 6 months, then 99212 might be appropriate.