Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. Endocrinology Division, Department of Medicine, National University Hospital, Singapore, 1E Kent Ridge Rd, Singapore, 119228, Singapore. Endocrinology Division, Yong Loo Lin School of Medicine, National University Singapore, 10 Medical Dr, Singapore, 117597, Singapore. Division of Thyroid & Endocrine Surgery, Department of Endocrine Surgery, National University Hospital, Singapore, Singapore. rajeev_parameswaran@nuhs.edu.sg. Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Dr, Singapore, 117597, Singapore. rajeev_parameswaran@nuhs.edu.sg.