[rat9988]

Why would you assume they didn't? They most likely did.

[carlmr]

From the quote it says they only adjusted for age and smoking.

[tssva]

The quote says the factors included age and smoking not that they only included age and smoking.

[carlmr]

I did indeed not read that properly. I'd have to check the actual publication. It's at least suspicious that they don't mention it, since obesity is probably the first thing you should think of when saying diabetes.