The value of semi-automatic ultrasound measurement of carotid artery intima-media thickness in the evaluation of vascular health in children and adolescentsDrole Torkar, Ana (Avtor) Kotnik, Primož (Mentor) vascular healthcarotid intima-media thicknesscIMTcardiovascular riskatherosclerosisultrasoundBackground. Early identification of children at risk of atherosclerosis (AS) is paramount for implementing primary preventive measures addressing vascular health. This dissertation presents the background of the pathophysiology of AS development in children, with the cohorts of children carrying risk factors for early vascular aging. Known methods of vascular health evaluation focusing on ultrasound technology, which evaluates changes in the vascular wall of the peripheral vascular tree, are briefly introduced. Among these methods, a noninvasive biomarker of AS progression, carotid intima–media thickness (cIMT), was chosen to evaluate vascular wall properties in the study population. A new semi-automatic technology, $^{RF}$QIMT, is claimed to be useful for non-radiology and non-cardiology specialists in clinical practice, and it was tested. However, this method has no known reference values for the European healthy pediatric population. Objectives. To evaluate the normative values of cIMT, the radiofrequency-based software-guided technique RF-Quality Intima–Media Thickness ($^{RF}$QIMT) was used in a healthy cohort of Caucasian children 6 to 18 years old. In addition, the correlation of sex, age, height, pubertal status, obesity, blood pressure, and low physical fitness with cIMT value was analyzed. Methods and Subjects. Healthy volunteers 6 to 18 years old were enrolled in the study with parental consent. Individuals with chronic illness were excluded. Age, chronic illness, medication use, and pubertal status were acquired with a questionnaire. Anthropometric and blood pressure measurements were obtained using standardized methods. Descriptive statistics for age, sex, pubertal developmental stage, anthropometrics, obesity measures, blood pressure, and physical fitness and their standard deviation scores were calculated. Sex-, age-, and height-specific normative values of cIMT for the $^{RF}$QIMT method were calculated using the LMS method for the non-obese and non-hypertensive sub-cohort (cohort A) of children. A systematic literature review of published normal cIMT values in children was carried out using the PRISMA methodology, and the normative values identified were compared to those in this study. The association of covariates was assessed with a one-way ANOVA test on a total healthy cohort (cohort B). In a sub-cohort with available physical fitness data and obesity scores from the SLOfit database (cohort C), the influence of physical fitness and obesity on cIMT progression was studied. A multiple linear regression model was used to analyze the effects of independent variables on cIMT. Statistical analysis was performed using R-project 3.6.0 software (https://cran.r-project.org) in all statistical calculations and analysis. Hypotheses. cIMT measured using the $^{RF}$QIMT method increases with age, linear growth, and pubertal maturation in children and adolescents 6 to 18 years old. Sex influences the cIMT value measured by the $^{RF}$QIMT method. The normative values of cIMT using the $^{RF}$QIMT method in children and adolescents 6 to 18 years old are comparable to the normative values of cIMT published in the literature that were established using other validated manual and semi-automatic methods of cIMT measurement. cIMT measured using the $^{RF}$QIMT method is already higher in children and adolescents in the presence of risk factors: obesity, higher blood pressure, and low physical fitness. Results. A total of 1,241 children were enrolled in the study. Of these, 1,202 healthy Caucasian children and adolescents 6 to 18 years old were included in the evaluation. From these, sub-cohort A of 1,137 non-obese normotensive children (males: n = 512; mean age 12.04 ± 3.52 years, females: n = 625, mean age 12.98 ± 3.83 years) were included in the calculation of sex, age, and height-specific normative cIMT using the LMS method. Normative values of cIMT measured using the $^{RF}$QIMT method are presented in the form of percentile charts, percentile tables, and LMS tables, separately for sex, age, and height for further clinical use. cIMT increased with age, height, hip circumference, and BMI, and it was was higher in males. Obesity, blood pressure, and poor physical fitness were associated with higher cIMT values for cohort C, for which the data from the SLOfit dataset were available. Conclusions. The $^{RF}$QIMT technique provided reliable measurements of cIMT for sex-, age-, and height-specific normative cIMT values in children 6 to 18 years old. In addition, the correlation of obesity, high blood pressure, and poor physical fitness with higher cIMT values can already be seen in the pediatric population.20232023-09-05 07:15:11Doktorsko delo/naloga149157VisID: 24392COBISS_ID: 169128707sl