you can do this via hook
public function onControllerPagesAccountEdit_UpdateData()
{
if (IS_ADMIN == true) {
return;
}
$that = &$this->baseObject;
$form = $that->view->getData('form');
$form['fields']['email']->attr .= ' readonly';
$form['fields']['telephone']->attr .= ' readonly';
$that->view->assign('form', $form);
}