The Atrial Fibrillation Risk Score for Hyperthyroidism Patients

Thyrotoxicosis (TT) is associated with an increase in both total and cardiovascu-lar mortality. One of the main thyrotoxicosis risks is Atrial Fibrillation (AF). Right AF predicts help medical personal prescribe the correct medicaments and correct surgical or radioiodine therapy. The main goal of this study is creating a method for practical treatment and diagnostic AF. This study proposes a new method for assessing the risk of occurrence atrial fibrillation for patients with TT. This method considers both the features of the complication and the specifics of the chronic disease. A model is created based on case histories of patients with thyrotoxicosis. We used Machine Learning methods for creating several models. Each model has advantages and disadvantages depending on the diagnostic and medical purposes. The resulting models show high results in the different metrics of the prediction of AF. These models interpreted and simple for use. Therefore, models can be used as part of the support and decision-making system (DSS) by medical specialists in the treatment and diagnostic of AF

Genetic and environmental influence on thyroid gland volume and thickness of thyroid isthmus: a twin study.

Objectives Decreased thyroid volume has been related to increased prevalence of thyroid cancer.Subjects and methods One hundred and fourteen Hungarian adult twin pairs (69 monozygotic, 45 dizygotic) with or without known thyroid disorders underwent thyroid ultrasound. Thickness of the thyroid isthmus was measured at the thickest portion of the gland in the midline using electronic calipers at the time of scanning. Volume of the thyroid lobe was computed according to the following formula: thyroid height*width*depth*correction factor (0.63).Results Age-, sex-, body mass index- and smoking-adjusted heritability of the thickness of thyroid isthmus was 50% (95% confidence interval [CI], 35 to 66%). Neither left nor right thyroid volume showed additive genetic effects, but shared environments were 68% (95% CI, 48 to 80%) and 79% (95% CI, 72 to 87%), respectively. Magnitudes of monozygotic and dizygotic co-twin correlations were not substantially impacted by the correction of covariates of body mass index and smoking. Unshared environmental effects showed a moderate influence on dependent parameters (24-50%).Conclusions Our analysis support that familial factors are important for thyroid measures in a general twin population. A larger sample size is needed to show whether this is because of common environmental (e.g. intrauterine effects, regional nutrition habits, iodine supply) or genetic effects

Association between serum free thyroxine concentration and atrial fibrillation.

BACKGROUND: Previous studies have suggested that minor changes in thyroid function are associated with risk of atrial fibrillation (AF). Our objective was to determine the relationship between thyroid function and presence of atrial fibrillation (AF) in older subjects. METHODS: A population-based study of 5860 subjects 65 years and older, which excluded those being treated for thyroid dysfunction and those with previous hyperthyroidism. Main outcome measures included tests of thyroid function (serum free thyroxine [T(4)] and thyrotropin [TSH]) and the presence of AF on resting electrocardiogram. RESULTS: Fourteen subjects (0.2%) had previously undiagnosed overt hyperthyroidism and 126 (2.2%), subclinical hyperthyroidism; 5519 (94.4%) were euthyroid; and 167 (2.9%) had subclinical hypothyroidism and 23 (0.4%), overt hypothyroidism. The prevalence of AF in the whole cohort was 6.6% in men and 3.1% in women (odds ratio, 2.23; P<.001). After adjusting for sex, logistic regression showed a higher prevalence of AF in those with subclinical hyperthyroidism compared with euthyroid subjects (9.5% vs 4.7%; adjusted odds ratio, 2.27; P=.01). Median serum free T(4) concentration was higher in those with AF than in those without (1.14 ng/dL; interquartile range [IQR], 1.05-1.27 ng/dL [14.7 pmol/L; IQR, 13.5-16.4 pmol/L] vs 1.10 ng/dL; IQR, 1.00-1.22 ng/dL [14.2 pmol/L; IQR, 12.9-15.7 pmol/L]; P<.001), and higher in those with AF when analysis was limited to euthyroid subjects (1.13 ng/dL; IQR, 1.05-1.26 ng/dL [14.6 pmol/L; IQR, 13.5-16.2 pmol/L] vs 1.10 ng/dL; IQR, 1.01-1.21 ng/dL [14.2 pmol/L; IQR, 13.0-15.6 pmol/L]; P=.001). Logistic regression showed serum free T(4) concentration, increasing category of age, and male sex all to be independently associated with AF. Similar independent associations were observed when analysis was confined to euthyroid subjects with normal TSH values. CONCLUSIONS: The biochemical finding of subclinical hyperthyroidism is associated with AF on resting electrocardiogram. Even in euthyroid subjects with normal serum TSH levels, serum free T(4) concentration is independently associated with AF