I am 46 years old and i am diabetic, i have some trouble walking far or climbing stairs, so is it a heart problem or a diabetes problem?

Possibly both: Diabetes does effect the blood vessels of the body. It may be possible for poor circulation to be the cause of your problems walking far distances or climbing stairs. Evaluation by your primary care physician and possibly a vascular doctor may be beneficial.

Or OTHER!!: 1. Unlikely diabetes- unless very weak from poorly controlled diabetes 2. Could be cardiac if associated with breathlessness, chest pressure/tightness 3. Most common is arthritis- back, hip, knee, ankles 4. Lung if breathless and smoking history.