[1] King Saud Univ, Coll Med, Dept Internal Med, Div Endocrinol, Riyadh 12372, Saudi Arabia
[2] Johns Hopkins Univ, Div Endocrinol Diabet & Metab, 1830 East Monument St, Baltimore, MD 21287 USA
[3] King Saud Univ, Coll Med, Dept Med, Riyadh 12372, Saudi Arabia
[4] King Saud Univ, Coll Med, Dept Internal Med, Div Endocrinol, Riyadh, Saudi Arabia