The fact that Hugh Hefner is still alive and kicking at 83 amazes me. Not because 83 is an unusually old age or anything, but because he’s lived quite the active life. I didn’t think you could have sex as much as Hef and live past your sixties. Though maybe that’s his secret. It’s constant exercise, if nothing else.

But according to insiders, Hef is looking the worse for wear lately. People are definitely starting to realize that he is an old man, and not just a committed swinger anymore. At a recent Playboy party he was seen shuffling around with the help of one of his girlfriends, and several sources say his recent romantic troubles haven’t helped things.

Hugh Hefner is still surrounded by bevies of busty beauties below the age of 25 — but is age finally catching up to the men’s magazine mogul?

The 83-year-old made a brief appearance at the Annual Kandyland Masquerade Ball at the iconic Mansion on Saturday night, but we’re told by numerous Playboy party regulars that while he appeared in good spirits, Hefner looked far from his normally alert and healthy self.

“He looked so old, like he had aged 10 years in the last month and was barely moving,” said an insider, adding that Hef’s new number one Crystal held his hand and assisted him as she “slowly shuffled” along while his other lovers (the 19-year-old Shannon twins) marched ahead of the bunny brigade and reveled in the limelight.

“I have some aches and pains and I have had lower back problems since the ’80s,” Hefner told Tarts last year. “Too much time in bed rustling around with friends.” But are Hef’s health concerns a little more serious these days and has it got to do with the recent upheaval of the Girls Next Door?

“Things aren’t quite the same since Holly and the girls left,” added our insider. “Hef loves all the new ones, but I think the transition really took its toll.”