Study design

This is a cross-sectional observational study, carried out from September 22, 2023 to December 17, 2024 at the regional reference service for outpatient treatment of children and adolescents with CHD in the state of Alagoas, “Casa do Coraçãozinho”, which is a partnership between “Sociedade Beneficente do Coração de Alagoas – CORDIAL” and “Hospital do Coração – HCOR”; it is the first center for pediatric cardiology subspecialties that provides care through the Unified Health System in the state. The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) checklist is available in Supplementary file 1.

Context

The state of Alagoas, where the municipality of Maceió is located in the northeast region of Brazil, has one of the lowest Human Development Indexes (HDI) in the country (0.684), ranking 26th in the national ranking [26]. Maceió has a municipal HDI (MHDI) of 0.721, while Inhapi has the worst MHDI in the state (0.484). Of the 102 municipalities in Alagoas, 86 have low HDI, and 2 have a very low HDI [27], marked by poverty, social inequality, low levels of education, limited access to health services and information on healthy habits, whether related to diet or lifestyle, factors that can contribute to the development of cardiovascular diseases [28]. Therefore, the average MHDI of the municipalities where the research participants reside is 0.574 (Supplementary file 2).

Participants

Participants were recruited, by convenience, to participate in the study prior after a routine consultation with a pediatric cardiologist or surgeon. Adolescents diagnosed with CHD, with medical records and followed at the referral clinic, aged between 10 and 18 years, of both sexes, were considered eligible for the study. Participants with inability to stand and/or move, inability to speak and/or hear or understand the questions presented, a diagnosis of Down syndrome; pregnancy; diagnosis of dwarfism and participants who refused to have blood collected were excluded.

Variables, Protocols and Standards

This study is primary analysis part of an umbrella Project called “Adolescents with congenital heart disease: A diagnostic study of lifestyle, physical fitness and cardiometabolic risk”. The variables of this study were collected through face-to-face interview, using an online platform (Google Forms®). Physical and laboratory examinations were performed, and all responses were tabulated in a Microsoft Excel® spreadsheet. All assessments, including questionnaires, tests and blood collection, were performed in a specific and private room for the research, by a qualified, trained and calibrated team.

First, the medical records were analyzed for screening and verification of eligibility criteria. Then, the participants were invited to the data collection room and, if accepted, the informed consent form was signed by the caregivers and the informed assent form by the adolescents (according to Brazilian legislation on research ethics). After acceptance, the questionnaires were applied by interview, related to sociodemographic and clinical data, physical activity practice and sedentary behavior. The research protocol included monitoring of vital signs and physical assessment (blood pressure, weight, height, waist circumference) and blood samples by a trained professional.

Outcome Variables—Cardiovascular Risk

The cardiovascular risk factors analyzed were: blood pressure (BP), anthropometric measurements (body mass index [BMI] and waist circumference), non-fasting lipid profile (total cholesterol (TC), triglycerides (TG)), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), and glucose were collected. The variables were analyzed, continuously and categorically.

Blood Pressure was measured on the right arm using an Omron digital sphygmomanometer (Hem-7122, São Paulo, Brazil), with the adolescent resting for at least 5 min, sitting with their back supported, feet on the floor and right arm resting at heart level. BP was measured twice, at the beginning of the questionnaire and before the physical assessments began according to standardization [29, 30]. The percentile based on age and sex was used as the cutoff point for BP assessment, cathegorized as normal if the measurements were under 90th percentile and abnormal, if above 90th percentile [31].

To assess body mass (in kilograms), was used a portable Omron digital scale (HBF-514c, Japan, 150 kg capacity) [32]. Height (in meters) was assessed using a portable stadiometer, with the adolescent in an upright position [32]. BMI data were calculated using Anthroplus software and interpreted according to World Health Organization (WHO) guidelines [33].

Waist circumference was assessed using a tape measure and refers to the circumference of the abdomen at its narrowest point between the tenth rib and the top of the iliac crest, perpendicular to the long axis of the trunk, measurements were taken at the end of a normal expiration, with participants standing, arms relaxed at their sides, feet together, and abdomen relaxed [30]. For its assessment, cutoff points were used according to age and sex [34].

The cutoff point for biochemical variables such as HDL-c, LDL-c, blood glucose, total cholesterol, and blood pressure followed the I Guideline for Atherosclerosis in Childhood (2005) [35] and Update of the Brazilian Guideline on Dyslipidemia and Atherosclerosis Prevention (2017) [36] (Supplementary file 3). The variables were dichotomized for the bivariate analysis, being determined astotal cholesterol: desirable and borderline/High, LDL: desirable and borderline/High, Triglycerides: desirable and borderline/High.

To assess cardiovascular risk, the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) score was used, which early stratifies individuals aged 15 to 34 years by adding the values ​​attributed to modifiable and non-modifiable fator [37, 38]. The PDAY score is calculated from the sum of points (Supplementary file 4) that are equivalent to the non-modifiable (age and sex) and modifiable (TC, HDL-c, BP, fasting glucose, non-HDL cholesterol, smoking and BMI) risk factors for atherosclerosis. Therefore, each risk factor assumes scores, which, when added, will result in the total cardiovascular risk score. Thus, the total score assigned to each risk variable will allow classification into low risk (≤ 0), intermediate risk (1–4), and high risk (≥ 5) for advanced coronary artery lesions.

Exposure Variables—Physical Activity and Sedentary Behavior, Clinical Conditions, Sociodemographic Factors

Habitual physical activity (PA) was assessed using the PAQ-C (Physical Activity Questionnaire for Children) questionnaire, applied in the form of an interview to the adolescents together with their guardians, which is a validated and reproducible (ICC ≈ 0.73–0.80, Cronbach’s alpha ≈ 0.70–0.71) questionnaire for the Brazilian population, with the aim of estimating the level of habitual physical activity in the last seven days, through nine self-reported questions about habitual PA practice coded from 1 to 5 (< 3 insufficient PA, > 3 sufficient PA) [39]recommended for children and adolescents with CHD (≥ 2.87 sufficient PA; <2.87 insufficient PA)[40].

The final score is calculated from the arithmetic mean of the averages of the first question, the average of the second to eighth question and the average of the ninth [41]. The questions address: the weekly frequency of leisure and sports activities, the practice of physical activity during physical education class, at lunchtime, after school, in the evening and on weekends, as well as the level of physical activity in the last seven days.

Sedentary behavior (SB) was assessed through screen time, which was assessed through questions from the QueST (Questionnaire for Screen Time of Adolescents) (ICC ≈ 0.24–0.76), developed for Brazilian adolescents to estimate screen time (in hours) in five constructs: studying, working/internship-related activities, watching videos, playing games, and using social media/chat applications [42]. The participant must answer in hours and minutes the time spent on the activity in question (< 120 min adequate SB, ≥ 120 min excessive SB), being an easy-to-understand and reproducible questionnaire. The definition of excessive sedentary behavior was used as those who, adding the time of the reported activities, remain in this way for 2 h or more, being considered sedentary, with the calculation being performed using the formula: ([volume on weekdays*5 + volume on weekend days*2]/7) [42].

The clinical conditions of the patients, including the type of CHD (cyanotic or acyanotic), complexity (simple, moderate or severe), number of cardiac surgeries (one or 2 or more), heart diseases were categorized according to the group: group 1: Conotruncal defects, group 2: Non-conotruncal defects, group 3: Coarctation of the aorta, group 4: Ventricular septal defect, group 5: Atrial septal defect, group 6: other cardiac and circulatory system anomalies [5] and the sociodemographic variables: sex (female and male), ethnicity (brown, black, yellow and White, according to self-assessment), family income (≤ 1 minimum wage; >1 minimum wage) considering the minimum wage of 2024 in Brazil ($ 262,00), caregiver literacy (< 10 years, ≥ 10 years), place of residence (capital, other locations) were evaluated through the medical records and questionnaire respectively.

Data analysis

The researchers responsible for data collection received prior training to minimize biases, in addition to conducting a pilot study. Relative and absolute frequencies (95% confidence intervals) were calculated for categorical variables and mean (or median) and standard deviation (or interquartile range) for continuous variables. The normality (Gaussian distribution) of the variables was analyzed using the Shapiro-Wilk test, histograms, kurtosis and skewness.

Chi-Square (X2) analysis was performed to observe the association between the outcome variables and the exposure variables. Student’s t-test and Mann-Whitney U-test were used to test the difference between the sexes in the descriptive analyses of the data. Binary logistic regression analyses were performed to identify factors associated with cardiovascular risk. Each cardiovascular risk factor—intermediate/high PDAY risk, elevated blood pressure, excessive waist circumference, elevated glycemia, altered total cholesterol, low HDL-c, altered LDL-c, and altered triglycerides—was analyzed as a dependent variable. Independent variables included categorical sociodemographic variables (age, sex, income, education of the person in charge, and location), clinical variables (complexity of heart disease and heart disease, and number of surgeries), and behavioral variables (physical activity level and sedentary behavior). All predictor variables were included simultaneously. A backward stepwise (non-conditional) procedure was applied to remove variables one at a time from the highest p value until the final model was obtained. The final adjusted models included only the variables that remained after the variable selection procedure, and these variables were adjusted simultaneously. Results were expressed as odds ratios (OR) with 95% confidence intervals (95% CI). All analyses were performed in the STATA® statistical package version 13.0 and in GraphPad Prism® version 5.0, establishing a p < 0.05.

Ethical Aspects

The study (CAAE: 70383923.9.0000.5012) was approved by the Research Ethics Committee of UFAL (No. 6,420,140). The adolescents’ participation occurred after the signing of the Free and Informed Consent Form (FICF) by their guardians and the Free and Informed Assent Form (FIAF) by the participants. All information was stored with classified access to the researchers, ensuring confidentiality and privacy of the participants.