Basically, it's this simple:
Take 2 of the same engine:
Build one with 200 hp, one with 500 hp. Which one will wear out quicker? Obviously the 500hp will.
All nitrous does is for very short periods make the engine wear like it's a higher HP engine. This is ASSUMING that the internals are OK with higher HP, and the ignition and fuel systems can handle it, too.
If the above applies, then nitrous will be just fine.
Now if you're doing something crazy, like adding a 400 hp nitrous kit to a stock engine, of course it won't like it. But as long as the engine is built to make the extra horsepower, or is one of those stock engines that have proven able to handle a lot more than stock HP, you should be fine.
Example: my race truck has a big block with about 640 hp. The rods are stock, with ARP bolts. They are pretty much at the limit of how much HP they can take, so I wouldn't even consider adding just a 125 shot of nitrous....I'd probably have engine failure.
But if my exact same bottom end was built to make only 350 hp normally, I'd have no problem with a 200+ shot of nitrous, since the internals can handle 600+ hp.
Of course, it would last longer running around with only 350hp vs 640 hp. That's a given, since it's obvious that making almost 300 hp more will put more of a strain on the components.
I'd say that it would last longer as a 350 hp engine with a 290 shot of nitrous, since it would only use the full power when racing, not all the time. Lots less wear, less valve spring pressure, etc.