de Vries TI, et al. - In a cohort of patients at high cardiovascular risk, researchers assessed the relationship between thyroid-stimulating hormone (TSH) levels within the normal range and the risk of type 2 diabetes mellitus (T2DM). In addition, they performed a systematic review and meta-analysis of studies evaluating the connection between plasma TSH levels in the normal range and incident T2DM in euthyroid patients. For this investigation, 5,542 patients without T2DM from the prospective Secondary Manifestations of ARTerial disease study with TSH levels between 0.35 and 5.0 mIU/L without anti-thyroid medication or thyroid-hormone replacement therapy were included. No apparent relation was found between plasma TSH levels in the normal range and incident T2DM in patients at high cardiovascular risk.