How to hide some profile in comments

Tawan,
That text is generated by Facebook itself, and it can't be hidden. Facebook determines, automatically, the best way to describe the user. I've honestly never seen the age field there. Usually, it's the company name or location of the user. You can see a good example of different fields that are shown on the comments on the page below:
www.sourcecoast.com/blog/extensions/jfbc...running-in-5-minutes

Hope that helps. I don't think most users would have their age displayed. I think that's just a weird thing they are doing with your own profile.

Thanks,
Alex