“…Thus, decreased serum TSH levels have been reported to be associated with surrogate markers of cardiovascular mortality including carotid wall thickness (1), atrial fibrillation (2, 3), high plasma fibrinogen levels (4), and left ventricular hypertrophy (5,6). However, results of studies on the association between decreased serum TSH levels or subclinical hyperthyroidism (3,(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) and mortality are conflicting. With respect to cardiovascular mortality, most studies (3,11,12,18) and all meta-analyses (10,14,17) detected no association between decreased serum TSH levels or hyperthyroidism and mortality, while two studies did detect an association (7,9).…”