An elevated parametric thyroid feedback quantile-based index is associated with atrial fibrillation.

Introduction: Atrial fibrillation is associated with hyperthyroidism. Within the euthyroid range, it is also associated with high thyroxine (fT4), but not with thyrotropin (TSH). We aim to describe differences in thyroid regulation, measured by the Parametric Thyroid Feedback Quantile-Based Index (PTFQI), between patients with atrial fibrillation and the general population.

A Cross-Sectional Study Examining the Parametric Thyroid Feedback Quantile Index and Its Relationship with Metabolic and Cardiovascular Diseases.

The usual inverse correlation between thyrotropin (TSH) and thyroid hormone disappears in syndromes of central resistance to thyroid hormone, where both are high. TSH and thyroid hormone are also simultaneously high when there is an elevation of the set point of the thyroid regulation axis. This can be estimated with indices, such as the Parametric Thyroid Feedback Quantile-based Index (PTFQI), which was designed for the general population.

Levothyroxine therapy and imatinib.

Levothyroxine requirements in patients with hypothyroidism are usually stable. Consequently, thyroid function is usually monitored once or twice yearly. Occasionally, the dose of levothyroxine can be changed by pharmacological reactions.