What is the point of "de" in this sentence?

Question

I'm reading a French article to practice my reading skills and I've come across this sentence:

Les scientifiques ont constaté qu'une personne seule a un risque accru de 29% de souffrir d'une crise cardiaque ou d'une angine de poitrine et 32% plus de risque d'être victime d'un AVC

I understand it pretty clearly, however, what is the point of "de" in "de souffrir..." and "d'être victime..."?

I understand that some verbs have de go after the infinitive, like for example permettre de, however I haven't heard of de going before the infinitive verb or anything like that.

Could someone explain to me why this is? Is there a rule for this use of de or something?

Thank you.

Answer 1

That's the very same rule you already mentioned about permettre de.

Here the expression is avoir un risque de, i.e. risquer de.

Answer 2

Not specific to French:
What kind of risk ?
A risk of suffering...

The same in French:
Quel genre de risque ?
Le risque de souffrir...