1. From the Department of Medicine, Division of Nephrology, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
2. Correspondence: jamal S. Alwakeel · Division of Nephrology, Department of Medicine (38), King Khalid University Hospital, PO Box 2925, Riyadh 11461, Saudi Arabia · T: +966-1-4671531, F: +966-1-4672558 · jwakeel@ksu.edu.sa · Accepted: October 2010
3. From the Division of Nephrology, Security Forces Hospital, Riyadh, Saudi Arabia
4. From the Department of Family and Community Medicine, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia