While this is not directly supported, you can fake it nevertheless. Use a circle shape that you resize small enough (hold down Shift while resizing), connect it by an edge without any arrow heads, and enter your attribute's name as the label text. Move the label to the side of the circle.
(To duplicate, you can: select a circle, press Ctrl-D.)
(To create the underlined label text, use HTML markup in the label text.)
Drawback of this solution: the faked attributes don't play well with automatic layout.