The relation of thyroid function and ventricular repolarization : Decreased serum thyrotropin levels are associated with short rate-adjusted QT intervals

Context: The linkage of thyroid dysfunction with ventricular repolarization properties has not been investigated extensively, although alterations might be associated with an increased ventricular vulnerability. Objective: The objective of the study was to investigate whether there is an association between functional thyroid status and rate-adjusted QT intervals (QTc). Design, Setting, and Participants: The population-based Study of Health in Pomerania included 4310 subjects aged 20–79 yr. Data of 3610 subjects (1862 women and 1748 men) without branch bundle blocks or pacemaker were available for the present analyzes. Main Outcome Measures: QTc with respect to thyroid status. Short QTc was defined below the 25th percentile, and long QTc above the 75th percentile of the gender-specific distribution. Results: TSH levels were positively associated with QTc independent from potential confounders in multivariable analyses (P for trend = 0.001). Subjects with decreased TSH levels had shorter QTc than those wit...