Donald Trump turned 78 on Friday, a birthday that puts the spotlight on his own age amid a presidential contest in which either of the two major-party candidates would enter office as the oldest president in the nation’s history.

President Joe Biden’s age and mental fitness have been longstanding worries among voters and the topic of persistent media coverage. Trump’s campaign and its allies have also played up his 81-year-old rival’s apparent gaffes, even sharing manipulated clips that have been edited to remove context.

Yet Trump’s own mental state is getting renewed attention — and some apprehension. According to CNBC anchor Andrew Ross Sorkin, several CEOs who met with Trump at a business roundtable on Thursday left the meeting with concerns about his cognitive state.

“I spoke to a number of CEOs — who I would say walked into the meeting being Trump supporter-ish or thinking that they might be leaning that direction — who said that he was remarkably meandering, could not keep a straight thought, was all over the map,” Sorkin said on Friday morning.

The people he spoke to “actually walked out of the room less predisposed to him,” Sorkin said, adding that one person told him it may “not be any different or better than Biden,” suggesting a lack of contrast between the two men’s mental fitness for the highest office. (The Washington Post’s Aaron Blake has argued that the real comparison to Biden’s age and mental fitness should be Trump’s judgment and stability.)

For his birthday, Trump entertained a celebration during a meeting with Republican lawmakers on Capitol Hill the day before, and he is scheduled to host an event with supporters in Florida on Friday night.

The former president — who believes that a person is like a battery with a finite amount of energy — has said in the past that 78 “is not old.”

This article was originally published on MSNBC.com