Effects of drugs on the efficacy of radioiodine (|) therapy in hyperthyroid patients

Prediction model for thyrotoxic atrial fibrillation: a retrospective study

BACKGROUND

Thyrotoxic atrial fibrillation (TAF) is a recognized significant complication of hyperthyroidism. Early identification of the individuals predisposed to TAF would improve thyrotoxic patients' management. However, to our knowledge, an instrument that establishes an individual risk of the condition is unavailable. Therefore, the aim of this study is to build a TAF prediction model and rank TAF predictors in order of importance using machine learning techniques.

METHODS

In this retrospective study, we have investigated 36 demographic and clinical features for 420 patients with overt hyperthyroidism, 30% of which had TAF. At first, the association of these features with TAF was evaluated by classical statistical methods. Then, we developed several TAF prediction models with eight different machine learning classifiers and compared them by performance metrics. The models included ten features that were selected based on their clinical effectuality and importance for model output. Finally, we ranked TAF predictors, elicited from the optimal final model, by the machine learning tehniques.

RESULTS

The best performance metrics prediction model was built with the extreme gradient boosting classifier. It had the reasonable accuracy of 84% and AUROC of 0.89 on the test set. The model confirmed such well-known TAF risk factors as age, sex, hyperthyroidism duration, heart rate and some concomitant cardiovascular diseases (arterial hypertension and conjestive heart rate). We also identified premature atrial contraction and premature ventricular contraction as new TAF predictors. The top five TAF predictors, elicited from the model, included (in order of importance) PAC, PVC, hyperthyroidism duration, heart rate during hyperthyroidism and age.

CONCLUSIONS

We developed a machine learning model for TAF prediction. It seems to be the first available analytical tool for TAF risk assessment. In addition, we defined five most important TAF predictors, including premature atrial contraction and premature ventricular contraction as the new ones. These results have contributed to TAF prediction investigation and may serve as a basis for further research focused on TAF prediction improvement and facilitation of thyrotoxic patients' management.

Study on the relationship between hyperthyroidism and vascular endothelial cell damage

The aim of the research is to explore the relationship between hyperthyroidism, iodine, antithyroid drugs (propylthiouracil) and vascular endothelial injury. In total, 136 SD rats were randomly allocated into the control group, the hyperthyroidism group, the hyperthyroidism propylthiouracil group, the hyperthyroidism low iodine group, the high iodine group, and the endothelial injury group. Rats were raised for 60 days. Afterward, indicators concerning endothelial damage were determined, including the von Willebrand Factor (vWF), thrombomodulin (TM), nitric oxide (NO), endothelin 1 (ET-1), and P-selectin, as well as the plant hemagglutinin sample type oxidized low-density lipoprotein receptor 1 (LOX-1) from the aorta and the number of endothelial progenitor cells (EPCs) in whole blood. The hyperthyroidism group had significantly higher values for vWF, TM, NO, ET-1, and P-selectin in serum and a higher number of EPCs in whole blood compared with the control group, similar to the LOX-1 expression in abdominal aorta. The hyperthyroidism low iodine group had significantly higher values for vWF, ET-1, and P-selectin in serum and a higher number of EPCs in whole blood compared with those of the control group, as was the case for LOX-1 expression in the abdominal aorta. The hyperthyroidism propylthiouracil group had significantly higher values for FT₄ in the serum compared with those in the control group. The electron microscope showed that hyperthyroidism caused a certain degree of endothelial injury to the abdominal aorta in rats. Hyperthyroidism can damage the vascular endothelium and is a high-risk factor for cardio-cerebrovascular disease. Propylthiouracil could be used in the treatment of hyperthyroidism, thus protecting endothelial cells from damage.

Prognostic factor analysis in 325 patients with Graves' disease treated with radioiodine therapy

Introduction

¹³¹I therapy is a choice for Graves’ hyperthyroidism. Several factors that affect the success of ¹³¹I treatment in Graves’ disease (GD) patients have been put forward. The aim of this retrospective study was to evaluate the factors influencing the success of ¹³¹I therapy and the occurrence of hypothyroidism after ¹³¹I therapy.

Patients and methods

We reviewed 325 GD patients, who were well documented out of 779 cases, treated with ¹³¹I in the First Affiliated Hospital of Xi’an Jiaotong University between 2010 and 2016. We collected the potential influencing factors, including demographic data (age, sex, family history), iodine intake state, antithyroid drugs (ATD) taking, thyroid texture, complications of hyperthyroidism, physical and laboratory examinations [thyroid weight, effective ¹³¹I half-life time (T_eff), 24-h iodine uptake rate, tri-iodothyronine, thyroxine, free tri-iodothyronine (FT3), free thyroxine, thyroid-stimulating hormone, thyroglobulin antibody, thyroid microsome antibody, thyrotropin receptor antibody], and final administered dosages according to Quimby formula. The correlations between the prognosis of GD patients and these factors were analyzed by logistic regression analysis.

Results

Out of 325 patients, 247 (76.00%) were treated successfully with radioiodine. GD patients who were cured by ¹³¹I therapy were more likely to have smaller thyroid [odds ratio (OR)=0.988, 95% confidence interval (CI)=0.980–0.996, P=0.002], lower FT4 levels (OR=0.993, 95% CI=0.988–0.997, P=0.002), and shorter time of ATD withdrawal before ¹³¹I treatment (OR=0.985, 95% CI=0.975–0.996, P=0.002). Hypothyroidism occurred in 132 (41.00%) out of 325 patients. There was an increased risk of early hypothyroidism in patients with lower 24-h iodine uptake (OR=0.964, 95% CI=0.941–0.988, P=0.004), and treated with a lower total dose of iodine (OR=0.892, 95% CI=0.824–0.965, P=0.005) and a higher iodine dose per garm of thyroid tissue (OR=5.414E+14, 95% CI=45.495–6.444E+27, P=0.027).

Conclusion

Our results showed that ¹³¹I treatment was more successful in patients with lower weight of the thyroid, lower free thyroxine level, and shorter ATD taking period. Furthermore, early hypothyroidism after radioiodine treatment was more likely to occur in patients with lower 24-h iodine uptake, lower total dose of iodine, and higher iodine dose per garm of thyroid tissue.

Using ultrasound radio frequency technology to assess regression of the structure and function of the carotid artery by radioiodine therapy in hyperthyroidism patients

INTRODUCTION

The aim of the study was to investigate the structure and function of the carotid artery in patients with hyperthyroidism by ultrasound radio frequency data technology (RF data) and the effect of (131)I on them.

MATERIAL AND METHODS

Seventy patients with primary hyperthyroidism and 74 healthy volunteers were enrolled in this study. Structural and functional parameters of the common carotid artery were measured in every patient before and after (131)I treatment through the RF data, such as intima media thickness (IMT), functional compliance coefficient (CC), stiffness index (β), and pulse wave velocity (PWV). We also analyzed the correlation between these parameters and patients' age, body mass index, hemodynamic parameters (blood pressure, heart rate), thyroid hormone levels and other risk factors.

RESULTS

There was a significant difference in IMT between hyperthyroid patients and the control group at baseline (483.6 vs. 443.3 µm, p < 0.01); after treatment, the IMT decreased significantly (428.7 vs. 483.6 µm, p < 0.001). Furthermore, the IMT was correlated with patients' age and systolic blood pressure (r = 0.525, p < 0.01 and r = 0.289, p < 0.05, respectively). The β and PWV were also higher than the control group (7.26 vs.5.87, 6.27 vs. 5.57 m/s, respectively; all p < 0.001); CC was lower than the control group (0.98 vs. 1.19 mm(2)/KPa, p < 0.01); after treatment, PWV and β were lower than baseline (5.66 vs. 6.27, 5.81 vs. 7.26 m/s, respectively; all p < 0.01), and CC was higher than baseline. In addition, they were significantly correlated with age (r = 0.525, p < 0.01 and r = 0.289, p < 0.05, respectively). However, these parameters were not correlated with the level of thyroid hormones.

CONCLUSIONS

Six-month (131)I treatment for patients with hyperthyroidism reverses the structural and functional damage in the carotid artery, which is sensitively evaluated by the RF data technique.

Redistribution of body composition in patients with Graves' disease after iodine-131 treatment

OBJECTIVE

The objective of this study was to investigate body composition redistribution at 3 months after radioactive iodine therapy (RAI).

METHODS

Eighty patients with Graves' disease (GD) for RAI and 18 volunteers were recruited. All patients underwent thyroid status test and dual-energy x-ray absorptiometry at baseline and 3 months after RAI. According to the second thyroid status test, patients were divided into the following groups: A, with aggravated hyperthyroidism; B-1, with improved hyperthyroidism; B-2, with euthyroidism; and B-3, with hypothyroidism.

RESULTS

Total lean mass (LM) but fat mass (FM) and bone mineral content (BMC) of whole GD patients after RAI recovered to be not different with controls. Compared with baseline, in group A, FM in the left leg increased, and LM in left arm, right arm, trunk and total LM decreased (P<0.05). In B-2, FM in the head increased, and LM in the head, right arm, trunk and total LM increased (P<0.05). In B-3, FM in the right leg and total body fat percentage decreased, but FM in the head, android-to-gynoid fat ratio and body mass index increased (P<0.05); LM of all sites, weight and total mass increased (P<0.05); BMC in lumbar spine and left leg, and total BMC decreased (P<0.05). Body composition of unmentioned sites was retained after RAI in each group (P>0.05).

CONCLUSIONS

Replenishment of LM gets priority rather than FM and BMC during the first 3 months after RAI, and the increase in LM starts from the upper body; head is the regional site in which FM recovery occurs first.

Hyperthyroidism and cardiovascular complications: a narrative review on the basis of pathophysiology

Cardiovascular complications are important in hyperthyroidism because of their high frequency in clinical presentation and increased mortality and morbidity risk. The cause of hyperthyroidism, factors related to the patient, and the genetic basis for complications are associated with risk and the basic underlying mechanisms are important for treatment and management of the disease. Besides cellular effects, hyperthyroidism also causes hemodynamic changes, such as increased preload and contractility and decreased systemic vascular resistance causes increased cardiac output. Besides tachyarrythmias, impaired systolic ventricular dysfunction and diastolic dysfunction may cause thyrotoxic cardiomyopathy in a small percentage of the patients, as another high mortality complication. Although the medical literature has some conflicting data about benefits of treatment of subclinical hyperthyroidism, even high-normal thyroid function may cause cardiovascular problems and it should be treated. This review summarizes the cardiovascular consequences of hyperthyroidism with underlying mechanisms.

Peripheral blood lymphocyte apoptosis and its relationship with thyroid function tests in adolescents with hyperthyroidism due to Graves' disease

INTRODUCTION

Failures in apoptotic pathways can contribute to various autoimmune diseases, including autoimmune hyperthyroidism due to Graves' disease (GD). The aim of the present research was to assess changes in the degree of peripheral blood (PB) lymphocyte apoptosis during methimazole (MMI) treatment in the group of teenage children, and to describe its relationship with thyroid function tests.

MATERIAL AND METHODS

The percentage of PB apoptotic lymphocytes, assessed by the decrease in mitochondrial transmembrane potential (CMXRos staining), was measured in 30 adolescents at the time of diagnosis and after obtaining normalization of the thyroid hormone levels.

RESULTS

The percentage of apoptotic lymphocytes in previously untreated patients with GD (5.16 ±2.81%) was significantly lower (p = 0.000001) than the percentage of apoptotic cells in the same group of patients after obtaining methimazole-induced euthyroidism (10.72 ±4.66%). There was a correlation between the increase of the mean percentages of apoptotic lymphocytes and the reduction of FT4 levels (R = 0.63, p < 0.0001), as well as the reduction of TT3 levels (R = 0.95, p < 0.0001). The more signs and symptoms accompanying the diagnosis of GD, the higher was the increment of the degree of lymphocyte apoptosis observed during the MMI-treatment (R = 0.74, p < 0.0000001). The methimazole dosage correlated (R = 0.85, p < 0.0001) with the percentage of apoptotic cells.

CONCLUSIONS

The use of methimazole in treatment of hyperthyroidism due to GD leads to an increment of apoptotic cells in PB. Higher doses of methimazole cause a higher increase of apoptotic lymphocytes. Apoptosis induction of human PB lymphocytes seems to be one of the indicators of proper hyperthyroidism treatment.

Analysis of demographic and clinical factors affecting the outcome of radioiodine therapy in patients with hyperthyroidism

INTRODUCTION

The influence of demographic and clinical factors on the outcome of (131)I therapy in hyperthyroid patients has been examined, based on a retrospective evaluation of results obtained in patients submitted to (131)I treatment at the Department of Nuclear Medicine and Oncological Endocrinology, Medical University of Lodz (Province Hospital, Zgierz). The goal of the study was to analyse such factors as the age and sex of patients, disease duration, as well as the hormonal status before (131)I application, which could have an influence on the effects of therapy with radioiodine (131)I.

MATERIAL AND METHODS

The study involved 500 randomly selected patients with hyperthyroidism, treated with (131)I radioiodine. The following 3 groups were defined: group 1 - patients with multinodular goitre (MNG), n = 200; group 2 - patients with a single autonomous nodule of the thyroid (AFTN), n = 100; group 3 - patients with Graves' disease (GD), n = 200. The local ethics committee (in the Polish Mother's Memorial Hospital - Research Institute, Lodz) approved the study.

RESULTS

The obtained results indicate that the efficacy of therapy with (131)I applied in patients with MNG, AFTN and GD does not depend on either patient sex or patient age. The length of antithyroid treatment before (131)I therapy onset does not appear to have any effect on the therapy outcome, and the baseline thyrotropin concentration seems to be significant only in the case of GD.

CONCLUSIONS

The analysed demographic factors do not affect the outcome of (131)I therapy in hyperthyroidism.