Admin Priviliges Question

I want to use this code in my phpinclude to determine if the user can control panel, and if so then create an additional icon in the fivelinks:

PHP Code:

$getperms=$DB_site->query_first("
SELECT cancontrolpanel
FROM user,usergroup
WHERE user.usergroupid=usergroup.usergroupid
  AND user.userid='$bbuserinfo[userid]'");
if ($getperms[cancontrolpanel]!=1) {
  // does not have admin rights
} else {
  // has admin rights
} 


However, this causes extra access to the database! Right?

Are user permissions pre-loaded into any available variables (like $bbuser) or will this become inefficient? Especially considering that this is added to EVERY page...

Thoughts?

If this isn't the right forum for this question let me know - I figured this area was more appropriate for PHP coding specifics.