Biden responding well to sleep apnea treatment; is 'healthy' and 'robust,' says his doctor.

President Joe Biden has been responding well to the treatment he has been receiving for sleep apnea, his doctors said after his annual routine physical Wednesday at Walter Reed National Military Medical Center.

All his other medical considerations remain "stable and well-controlled," the doctor's report concludes.

"President Biden is a healthy, active, robust 81-year-old male who remains fit to successfully execute the duties of the Presidency," according to the report.

The report also notes the president's gait remains stiff but has not worsened since last year.

X-rays reveal mild arthritic changes that have contributed to his stiffened gait, said Dr. Kevin C.O. Connor, the president's physician. He concluded, however, that no treatment was warranted other than physical therapy.

A written summary of the results of the physical was published by the White House.

Last February, a skin lesion was removed from Biden’s chest. Known as a basal cell carcinoma, a common form of skin cancer, his doctor said then that no further treatment was required.

At 81, Biden is the oldest sitting president, and a myriad of polls have shown that it is a significant concern for voters heading into the 2024 presidential election.

Earlier this month, a group of House Republicans wrote to Biden demanding that he take a cognitive test to prove his mental fitness for office after Robert Hur’s special counsel investigation on Biden's handling of classified information portrayed Biden as an elderly man with "diminished capacities," including memory loss.

Asked at the White House news briefing later in the day whether the president had undergone a cognitive test, Karine Jean-Pierre, the president's press secretary, said he hadn't.

"The president doesn't need a cognitive test," she said. She said that wasn't only her assessment, but it was the assessment of a neurologist, adding that Biden "passes a cognitive test every day."

"We have to keep that in mind ... this is a very rigorous job," she said.

The White House said earlier this month that the president would not take a cognitive test as part of his physical.

Sleep apnea is a common disorder in which breathing is interrupted repeatedly during sleep. The American Medical Association estimates that about 30 million people in the United States have sleep apnea, but only 6 million have been diagnosed with the condition.

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Common symptoms include loud snoring, episodes in which one stops breathing during sleep, gasping for air during sleep, and fatigue even after a full night's rest.

Biden was asked Monday about his age by comedian Seth Meyers on “Late Night with Seth Meyers” on NBC late Monday night. Biden pointed to his potential rival in the 2024 presidential election, former President Donald Trump, who is 77.

“Look at the other guy. He is about as old as I am but he can't remember his wife’s name,” he joked, before striking a more serious note. “It's about how old your ideas are. Look, I mean, this is a guy wants to take us back. He wants to take us back on Roe v. Wade. He wants to take us back on a whole range of issues that are 50, 60 years.”

This article originally appeared on USA TODAY: 'Active' and 'robust' Biden had a physical exam without a cognitive test