WASHINGTON (AP) — AIDS is graying. By the end of the decade, the government estimates, more than half of Americans living with HIV will be over 50. Even in developing countries, more people with the AIDS virus are surviving to middle age and beyond.

That's good news — but it's also a challenge. There's growing evidence that people who have spent decades battling the virus may be aging prematurely. At the International AIDS Conference this week, numerous studies are examining how heart disease, thinning bones and a list of other health problems typically seen in the senior years seem to hit many people with HIV when they're only in their 50s.

"I'm 54, but I feel older," said Carolyn Massey of Laurel, Md., who has lived with HIV for nearly 20 years.

"When I hear young people talk about, 'Well you get HIV and you take your drugs and you'll be all right' — that's just not the truth," she said. "This is a lifelong thing we're talking about, and it unfolds every day on you."

The graying isn't just because people like Massey are surviving longer. Some of it comes from older adults being newly diagnosed, a trend U.S. health officials say is small but slowly growing. Yes, grandparents still have sex — and that's an age group missed by all those hip safe-sex messages aimed at teens and 20-somethings.

"They let down their guard," is how Dr. Kevin Fenton of the Centers for Disease Control and Prevention puts it.

Already, a third of the nearly 1.2 million people living with HIV in the U.S. are over 50, and by 2020 half will be, Fenton said at one of numerous sessions on aging at the world's largest AIDS meeting.

People 50 or older accounted for 17 percent of new HIV diagnoses in 2009, according to the CDC's latest data. That's up from 13 percent in 2001.

There aren't as good counts in poor regions of the world, where access to life-saving medications came years later than in developed countries.

But even in hard-hit sub-Saharan Africa, home to most of world's HIV-infected population, studies suggest 3 million people living with HIV are 50-plus, said Dr. Joel Negin of the University of Sydney in Australia. By 2040, he said, that could reach 9 million.

There, challenges are different. Ruth Waryaro of Kenya, addressing the conference on her 65th birthday, said clinic workers hassle her when she goes to pick up her monthly supply of medication — not believing a grandmother really needs it.

"If you're not strong enough, you just leave the medication and go home," said Waryaro, who raised four children of her own and now is raising four AIDS orphans. She also has diabetes and high blood pressure.

As Negin pointedly told the conference, "50 is not old." But for years, world health authorities didn't even measure HIV in people beyond age 49.

Today, people who are diagnosed and treated early can expect a near-normal life-span, Dr. Anthony Fauci, infectious disease chief at the National Institutes of Health, told The Associated Press.

The new focus is on what these pioneering survivors can expect as they reach their 50s, 60s and beyond. They're now getting chronic illnesses such as heart disease, diabetes, kidney disease and osteoporosis — some of the common ailments when anyone gets old. But studies suggest people with HIV may be at higher risk for some of those illnesses, or get them earlier than usual.

"It's almost created a new subspecialty of medicine," Fauci said. Continued...