Abstract
Objectives:This study aimed at assessing the incidence of pulmonary hypertension (PH) at newly diagnosed hyperthyroid patients and at finding a simple model showing the complex functional relation between pulmonary hypertension in hyperthyroidism and the factors causing it.Methods:The 53 hyperthyroid patients (H-group) were evaluated mainly by using an echocardiographical method and compared with 35 euthyroid (E-group) and 25 healthy people (C-group). In order to identify the factors causing pulmonary hypertension the statistical method of comparing the values of arithmetical means is used. The functional relation between the two random variables (PAPs and each of the factors determining it within our research study) can be expressed by linear or non-linear function. By applying the linear regression method described by a first-degree equation the line of regression (linear model) has been determined; by applying the non-linear regression method described by a second degree equation, a parabola-type curve of regression (non-linear or polynomial model) has been determined. We made the comparison and the validation of these two models by calculating the determination coefficient (criterion 1), the comparison of residuals (criterion 2), application of AIC criterion (criterion 3) and use of F-test (criterion 4).Results:From the H-group, 47% have pulmonary hypertension completely reversible when obtaining euthyroidism. The factors causing pulmonary hypertension were identified: previously known- level of free thyroxin, pulmonary vascular resistance, cardiac output; new factors identified in this study- pretreatment period, age, systolic blood pressure. According to the four criteria and to the clinical judgment, we consider that the polynomial model (graphically parabola- type) is better than the linear one.Conclusions:The better model showing the functional relation between the pulmonary hypertension in hyperthyroidism and the factors identified in this study is given by a polynomial equation of second degree where the parabola is its graphical representation.
Highlights
Pulmonary hypertension on hyperthyroid patients is one of the most recent and up-to-date research topics
The conclusion of the studies shows that the hormonal excess is the proper cause of pulmonary hypertension due to the fact that pulmonary hypertension appears at the same moment with hyperthyroidism and disappears when the status of euthyroidism is obtained
The design of the study consisted in a determination of hormonal profile, an M and 2D Echocardiography combined with a tissue and spectral Doppler followed by the installment of a 24h EKG Holter and ABMP for 24 hour.These investigations were applied to the H-group, at the moment of inclusion, after 12 weeks of anti-thyroid treatment when euthyroidism by installing, and to the C-group at the time of enrollment
Summary
Pulmonary hypertension on hyperthyroid patients is one of the most recent and up-to-date research topics. The conclusion of the studies shows that the hormonal excess is the proper cause of pulmonary hypertension due to the fact that pulmonary hypertension appears at the same moment with hyperthyroidism and disappears when the status of euthyroidism is obtained. Instead, these coefficients of determination and correlation are small and lacking statistical significance. On the other hand, during the medical research, the evaluation of the determining relation between two variables one uses the coefficient of determination R2 usually calculated by using the linear regression method This one suggests the fact that the relation of determination between two variables is either increasing or decreasing, namely, a limitless relation. The relation of determination cannot be linear as physiological mechanisms of adaptation and regulation intervene and model this line
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
