Try this:

global $current_user;
$user_id = $current_user->ID; // current user ID
$meta = get_user_meta( $user_id, \'title\', \'Manager\' ); // subject meta

if($meta != \'\') // updates meta if exists
    update_user_meta($user_id, \'title\', \'Manager\');
else // creates new meta if not exists
    add_user_meta($user_id, \'title\', \'Manager\');