seeing as LCD don't have a refresh rate i doubt it.
Granted
As for the CRT, interesting question - not one I had every considered. In short yes, it might well shorten the life.
The phosphor dots are being hit and degraded by the electron beams 75 times per second instead of 60, which might suggest a 20% reduction in the time it takes for them to burn out or darken, a phenomenon known as 'photobleaching' (at least in fluorescence spectroscopy using light to excite the phosphors, not sure what it would be called here - 'electrobleaching'?).
In practice though this was a problem with earlier monitors (10-15 years ago) the phosphor technology in CRT's has improved greatly. The chances are your CRT will die of some other problem before this every becomes an issue.