1. 1Department of Medicine, University of the Free State, Bloemfontein, South Africa
2. 2Department of Medicine, Dubai Medical College, Duabi, United Arab Emirates
3. 3Department of Endocrinology, Mediclinic Airport Road Hospital, Abu Dhabi, United Arab Emirates
4. 4Division of Endocrinology, Department of Medicine, University of Cape Town, Cape Town, South Africa