"Has anyone noticed how people who do not sleep a lot "look old" - I mean with wrinkles, spots, etc."
Absolutely. But I will also add that the spots and the wrinkles can come from to much exposure to the sun which can also come from having the money to take vacations in the sun or have summer homes. Excess sun exposure really ages people.
People lose their hair color due (primarily) to a lack of catalase, which normally removes hydrogen peroxide. It is now thought that much of this work is done during sleep. So, assuming this theory is true, a lack of sleep (an effect every president has mentioned) does cause people to go gray.
Stress is a contributor too, even if you sleep well. Clinton was known as a night owl but Bush, by most reports, got plenty of sleep and he still aged a lot.
Look at investment bankers - their chronological age does not seem to match their physical appearance.
This article gives a potential explanation - bad sleep changes protein expression, but I'm curious about the visible outcomes.
Hopefully there are many sleep deprived founders, and well rested lifestyle entrepreneurs (sorry for the cliché!) reading this thread.
Do people tell you you look younger/older than what you are? And how old are you??