English is a very sloppy language. There are many ambiguities in the statement. Some of them are more obviously absurd than others.
- "Diabetes" could refer to my pet dog Diabetes.
- "can lead to" is extremely vague. Does it imply a factual causal link ("if you have diabetes, then your diabetes may cause your heart to become faulty") or a roundabout route ("if you have diabetes, then you will take insulin, which will cause heart problems"), or a correlation ("if you have diabetes, then this is an indication that you are genetically predisposed to get heart disease later"), or any one of a number of other things?
- "Deadly heart problems" could mean that my heart problems are deadly to others (if I'm a pilot and my arrhythmia makes me feel faint), or that they're deadly to myself.
- "Deadly heart problems" can mean "problems with my deadly heart" (perhaps my heart contains lots of vitamin A which is poisonous when consumed).
If you're interested in this kind of thing, I recommend studying the grammar of the constructed language Ithkuil, which is really precise about lots of things which English simply leaves to context.