Associations of Thyroid Hormones and Resting Heart Rate in Patients Referred to Coronary Angiography

Abstract

Resting heart rate (RHR) is associated with increased risk of cardiovascular morbidity and mortality. Thyroid hormones exert several effects on the cardiovascular system, but the relation between thyroid function and RHR remains to be further established. We evaluated whether measures of thyroid hormone status are associated with RHR in patients referred to coronary angiography. Thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxin (FT4), and RHR were determined in 2795 participants of the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study. Median (25th to 75th percentile) serum concentrations were 1.25 (0.76–1.92) mU/l for TSH, 4.8 (4.2–5.3) pmol/l for FT3 and 17.1 (15.4-19.0) pmol/l for FT4, and mean (±standard deviation) RHR was 68.8 (±11.7) beats/min. Comparing the highest versus the lowest quartile, RHR (beats/min) was significantly higher in the fourth FT4 quartile [3.48, 95% confidence interval (CI): 2.23–4.73; p <0.001] and in the fourth FT3 quartile (2.30, 95% CI: 1.06–3.55; p <0.001), but there was no significant difference for TSH quartiles. In multiple linear regression analyses adjusting for various potential confounders, FT3 and FT4 were significant predictors of RHR (p <0.001 for both). In subgroups restricted to TSH, FT3, and FT4 values within the reference range, both FT3 and FT4 remained significant predictors of RHR (p <0.001 for all). In conclusion, in patients referred to coronary angiography, FT3 and FT4 but not TSH were positively associated with RHR. The relationship between free thyroid hormones and RHR warrants further investigations regarding its diagnostic and therapeutic implications.

Mathematical Modeling of Free Thyroxine Concentrations During Methimazole Treatment for Graves’ Disease: Development and Validation of a Computer-Aided Thyroid Treatment Method

“…Furthermore, currently, treatment recommendations are only possible for MMI, but not for alternative ATDs such as propylthiouracil. As thyroid hormones are significantly associated with heart rate (35), it is also tempting to speculate that integrating heart rate data obtained by common wearables such as smartwatches into our DigiThy application may also further improve our model, not only for guiding MMI dosing recommendations but also for detecting (re-) emerging hyperthyroidism. We also have to acknowledge that our work can only be considered a pilot study providing preliminary data on the characteristics and performance of our model and web application.…”

The Association of Thyroid Hormones with Coronary Atherosclerotic Severity in Euthyroid Patients

“…However, we conducted sensitivity analysis through multiple imputation and confirmed the robustness of the results. Due to lack of data, the positive association between thyroid hormones and resting heart rate under euthyroid condition, which has been revealed by Steinberger et al [5], was not explored further in this study.…”

“…Nevertheless, relatively less studies have focused on population with euthyroid status. For example, Steinberger et al have reported free triio dothyronine (FT3) and free thyroxine (FT4) were positively associated with resting heart rate [5]. In addition, several observational studies demonstrated FT3 level was inversely associated with the presence of CAD or the severity of coronary atherosclerosis in euthyroid subjects [6][7][8], however, FT4, FT3 to FT4 ratio (FT3/FT4 ratio) and thyroid stimulating hormone (TSH) were not investigated in those studies.…”