Its just the same with UK Politicians. Two that spring to mind are Tony Blair (PM) and Neil Kinnock (leader Labour Party).
Looks like it was worse on Bush than on Clinton. Which is only fair.
I was looking at pictures of Presidents the other day and several seemed to have aged terribly. Of course it must be the same with all leaders in most countries. And, true, they are several years older to start with. But the aging on some seems to be more dramatic than simply being 8 years older. Okay, not an earthshaking observation on my part!
Obama already looks older.