1. Division of Endocrinology and Metabolism, Department of Internal Medicine, Federal Medical Centre, Umuahia, Abia State, Nigeria
2. Division of Nephrology, Department of Internal Medicine, Federal Medical Centre, Umuahia, Abia State, Nigeria
3. Department of Community Medicine, Federal Medical Centre, Umuahia, Abia State, Nigeria
4. Department of Ophthalmology, Federal Medical Center, Umuahia, Abia State, Nigeria
5. Division of Cardiovascular Medicine, Department of Medicine, University College Hospital, PMB 5116, Dugbe GPO, Ibadan, Oyo State, Nigeria