'Night owls' may have worse heart health — but why?

A man sitting up in bed working on a laptop.

Some people hit their stride in the morning, while others feel most awake and productive at night. But a growing body of evidence suggests that being part of the latter group, the "night owls," could be linked to poorer heart health.

Now, a large study published Jan. 28 in the Journal of the American Heart Association adds weight to the idea.