Former Mayor Sophie Masloff -- slated to be the oldest delegate at next week's Democratic National Convention in Denver -- will not be going, due to health concerns.

Ms. Masloff, 90, said it is the first convention since 1960 that she will not be attending and she is "heartbroken" by the decision.

In an interview yesterday she said her doctor was worried about the altitude in Denver and the stress of the convention, but that her health is good overall.

"There are no big problems. I have all my marbles," she said.

The former mayor supported Sen. Hillary Rodham Clinton during the Pennsylvania Democratic primary but now favors Sen. Barack Obama. Unlike another big-name Clinton supporter, Gov. Ed Rendell, Ms. Masloff said she was not planning to cast a symbolic roll-call vote for Mrs. Clinton.

"We're united behind 'O,'" she said.

The Democratic National Convention Committee named Ms. Masloff as the convention's oldest delegate in a release that went out to news organizations nationwide.

The committee had no immediate comment. It was looking into who would be the next-oldest delegate.