Scarneciu Camelia C, Sangeorzan Livia, Rus Horatiu, Scarneciu Vlad D, Varciu Mihai S, Andreescu Oana, Scarneciu Ioan
Camelia C. Scarneciu, MD, PhD. Faculty of Medicine, Transilvania University of Brasov, Brasov, Romania.
Livia Sangeorzan, PhD. Faculty of Mathematics and Computer Science, Transilvania University of Brasov, Brasov, Romania.
Pak J Med Sci. 2017 Jan-Feb;33(1):111-120. doi: 10.12669/pjms.331.11046.
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.
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).
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.
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.
本研究旨在评估新诊断的甲状腺功能亢进患者肺动脉高压（PH）的发生率，并找到一个简单模型来展示甲状腺功能亢进症中肺动脉高压与其致病因素之间的复杂功能关系。
主要采用超声心动图方法对53例甲状腺功能亢进患者（H组）进行评估，并与35例甲状腺功能正常者（E组）和25例健康人（C组）进行比较。为了确定导致肺动脉高压的因素，采用比较算术平均值的统计方法。两个随机变量（肺动脉收缩压和本研究中决定它的各因素）之间的功能关系可用线性或非线性函数表示。通过应用由一次方程描述的线性回归方法确定回归直线（线性模型）；通过应用由二次方程描述的非线性回归方法确定抛物线型回归曲线（非线性或多项式模型）。我们通过计算决定系数（标准1）、残差比较（标准2）、应用AIC标准（标准3）和使用F检验（标准4）对这两个模型进行比较和验证。
在H组中，47%的患者在甲状腺功能恢复正常时肺动脉高压完全可逆。确定了导致肺动脉高压的因素：已知因素——游离甲状腺素水平、肺血管阻力、心输出量；本研究中确定的新因素——治疗前期、年龄、收缩压。根据这四个标准以及临床判断，我们认为多项式模型（图形为抛物线型）比线性模型更好。
展示甲状腺功能亢进症中肺动脉高压与本研究中确定的因素之间功能关系的更佳模型由二次多项式方程给出，其图形表示为抛物线。
