President Donald Trump during a meeting in the Roosevelt Room of the White House in Washington, DC, January 11, 2018.

The threat of nuclear war with North Korea didn't kill the stock market's bull run. An ongoing federal investigation into possible collusion with Russia during the 2016 Presidential campaign didn't do it either. But beware a poor cholesterol reading.

President Donald Trump likes to take credit for last year's stock market gain, but on Thursday he admitted that the results of his scheduled medical examination on Friday could be responsible for its fall.

A reporter asked Trump on Thursday how he thought Friday's physical would go. "I think it's going to go very well," Trump said. "I'll be very surprised if it doesn't."

Trump is getting the customary presidential health check amid questions about his fitness for office. A summary of the results is typically made public, at least it has been during prior administrations. But already his diet has been widely discussed, including his proclivity for fast food, well-done steak with ketchup and diet cola.

The physical also comes as trade at record highs, with the major indexes pushing past milestone after milestone.

As an aside to his comment about the physical, Trump said, "It better go well otherwise the stock market will not be happy."