Effect of Time-Varying Exposure to School-Based Health Promotion on Adiposity in Childhood.

BACKGROUND: The results of most school-based health promotion initiatives are inconclusive. OBJECTIVES: This trial assessed the effect of time-varying exposures to a multicomponent school-based health promotion intervention (SI! Program) on adiposity markers. METHODS: A total of 48 schools in Madrid (Spain) were cluster randomized to receive the SI! Program through elementary education grades 1 to 6 (E1-6, 12 schools, 459 children), 1 to 3 (E1-3, 12 schools, 513 children), or 4 to 6 (E4-6, 12 schools, 419 children) or to receive the standard curriculum (control, 12 schools, 379 children). The primary endpoint was the between-group difference at 3- and 6-year follow-up in the change from baseline in adiposity markers and the overall knowledge-attitudes-habits (KAH) score. RESULTS: At 3-year follow-up, children who had the intervention showed significantly lower increases than the control group in z-scores for body mass index (BMI), waist-to-height ratio (WHtR), and waist circumference (WC) (zBMI: -0.09; 95% CI: -0.16 to -0.03; P = 0.003; zWC and zWHtR: -0.19; 95% CI: -0.28 to -0.10; P < 0.001). At 6-year follow-up, the beneficial trend in zWC and zWHtR was maintained in the E1-6 and E1-3 groups: difference zWC control vs E1-6 (-0.19; 95% CI: -0.36 to -0.03; P = 0.020), control vs E1-3 (-0.22; 95% CI: -0.38 to -0.06; P = 0.009); difference zWHtR control vs E1-6 (-0.24; 95% CI: -0.41 to -0.06; P = 0.009), and control vs E1-3 (-0.29; 95% CI: -0.47 to -0.11; P = 0.001). No significant between-group differences were found in the change of overall KAH score. CONCLUSIONS: Early elementary school interventions may be more effective than later interventions on abdominal adiposity. Further research should assess the sustainability effects of school-based health promotion programs.

Unlocking the power of polyphenols: A promising biomarker of improved metabolic health and anti-inflammatory diet in adolescents.

BACKGROUND: Metabolic syndrome (MetS) in adolescence is a risk factor for future cardiovascular disease. The chronic inflammation associated with MetS can be attenuated by the anti-inflammatory effect of polyphenols. We aimed to evaluate total urinary polyphenols as a biomarker of anti-inflammatory diets and their effect on MetS in adolescents. METHODS: In this retrospective analysis of a longitudinal cohort study, the relationship between total polyphenol excretion (TPE) in urine, the inflammatory potential of the diet measured through the Children's Dietary Inflammatory Index (C-DII), and the presence of metabolic syndrome was evaluated. The study population consisted of adolescents enrolled in the SI! Program for Secondary Schools trial, who had completed all the study forms and provided urine samples at baseline and at the two-year follow-up. Multivariate linear regression and multinominal logistic regression models were generated to evaluate the relationship of changes in TPE with changes in the C-DII score and changes in MetS status, respectively. An analysis of the ROC curve was performed to assess the potential of TPE as a biomarker of an anti-inflammatory diet. RESULTS: This study included 662 adolescents, 51.2% were males, and 48.8% were females, with a mean age of 12 (0.38) years at baseline. The relationship between changes in TPE and changes in the C-DII score was stratified by sex with a p-value <0.001 for the interaction. TPE and C-DII were inversely associated in males (-0.13 mg GAE/g creatinine [-0.26; -0.01] per 1-SD increase, p-value = 0.037). In addition, an increase in changes in TPE levels were associated with a reversal in MetS status in all adolescents (1.30 [1.27; 1.34] per 1-SD increase, p-value<0.001). The ROC curve showed that urinary TPE levels can predict dietary inflammatory potential with an AUC = 0.793 (0.725; 0.863) in males. CONCLUSION: Polyphenols excreted in urine are a potential biomarker of anti-inflammatory diets in males and are associated with a reversal of MetS status in adolescents. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, Identifier: NCT03504059, https://clinicaltrials.gov/study/NCT03504059.

Adolescent Reference Values for MR-Derived Biventricular Strain Obtained Using Feature-Tracking and Myocardial Tagging.

BACKGROUND: Myocardial strain is a promising marker for the detection of early left or right ventricular (LV or RV) dysfunction in pediatric populations. The reference standard for MR strain measurement is myocardial tagging (MT); however, MT has limited clinical utility because the additional acquisitions needed are time-consuming. In contrast, MR-feature tracking (FT) allows strain quantification from routinely acquired cine sequences. Studies providing reference values obtained with both FT and MT for adolescents are lacking. PURPOSE: To use MR-FT and MT to define sex-specific LV and RV strain reference values for adolescents. STUDY TYPE: Cross-sectional, prospective. POPULATION: One hundred twenty-three adolescents aged 15-18 years (52% girls) without known cardiovascular disease. FIELD STRENGTH/SEQUENCE: Balanced steady-state free-precession sequence for FT analysis and a spatial modulation of magnetization hybrid TFE-EPI sequence for MT acquisitions at 3.0-T. ASSESSMENT: Segment Medviso software was used to obtain longitudinal (LS) and circumferential (CS) strain for both ventricles, and radial strain (RS) for LV. STATISTICAL TESTS: The Student t-test was used for between-sex comparisons of continuous variables. Sex-specific percentiles were calculated using the weighted average method. Intraobserver and interobserver agreement was assessed in 30 randomly selected studies using intraclass correlation coefficients (ICC). A P-value <0.05 was considered statistically significant. RESULTS: FT-derived LVLS and LVCS were significantly higher in girls than in boys (-19.8% vs. -17.8% and -22.2% vs. -21.0%, respectively), as they were with MT (LVLS: -18.1% vs. -16.8%; LVCS: -20.8% vs. -19.7%). FT-LVRS was higher in girls than in boys (44.8% vs. 35.1%), while MT-LVRS was the opposite (18.6% vs. 22.7%). FT-RVLS was higher in girls (-23.4% vs. -21.3%), but there were no between-sex differences in MT-derived RVLS or RVCS. ICC values for intraobserver agreement were ≥0.89, whereas for interobserver agreement were <0.80 for MT-LVRS and ≥0.80 for all remaining parameters. DATA CONCLUSION: This study provides sex-specific reference biventricular strain values obtained with MR-MT and MR-FT for adolescents aged 15-18 years. MR-FT may be a valid method for obtaining strain values in pediatric populations. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 3.

Cardiovascular Health Trajectories in Adolescence and Their Association With Sociodemographic and Cardiometabolic Outcomes in Spain.

PURPOSE: To determine cardiovascular health (CVH) trajectories and their association with sociodemographic and cardiometabolic outcomes in adolescence. METHODS: One thousand eighty adolescents attending 24 secondary schools enrolled in the SI! Program for Secondary Schools trial in Spain were assessed at approximately 12, 14, and 16 years of age. CVH was assessed according to American Heart Association criteria based on seven metrics (smoking status, body mass index, physical activity, diet, blood pressure, total cholesterol, and blood glucose), and CVH trajectories were identified by latent class trajectory modeling. Associations between CVH trajectories, sociodemographic characteristics, and cardiometabolic outcomes were analyzed using generalized linear and Poisson models. RESULTS: Five CVH trajectory groups were identified: poor-stable (27 adolescents [2.5%]), intermediate-substantial rise (79 [7.3%]), intermediate-substantial decline (63 [5.8%]), intermediate-mild decline (403 [37.3%]), and intermediate-mild rise (508 [47.1%]). Boys and adolescents from families with low-average income, low-intermediate educational attainment, and a migrant background more frequently belonged to groups with lower baseline CVH and poor or declining trajectories. The intermediate-substantial decline group had the highest prevalence ratio for overweight/obesity (3.84; 95% confidence interval: 2.86-5.16) and metabolic syndrome (4.93; 95% confidence interval: 1.21-20.04) at age 16, whereas prevalence was lowest in the intermediate-mild rise group. DISCUSSION: Adolescent CVH trajectories differ according to socioeconomic characteristics and are associated with cardiometabolic outcomes. Primordial prevention interventions should be implemented early in life, taking into account CVH trajectories and with a particular focus on vulnerable populations.

Oxidative Post-translational Protein Modifications upon Ischemia/Reperfusion Injury.

While reperfusion, or restoration of coronary blood flow in acute myocardial infarction, is a requisite for myocardial salvage, it can paradoxically induce a specific damage known as ischemia/reperfusion (I/R) injury. Our understanding of the precise pathophysiological molecular alterations leading to I/R remains limited. In this study, we conducted a comprehensive and unbiased time-course analysis of post-translational modifications (PTMs) in the post-reperfused myocardium of two different animal models (pig and mouse) and evaluated the effect of two different cardioprotective therapies (ischemic preconditioning and neutrophil depletion). In pigs, a first wave of irreversible oxidative damage was observed at the earliest reperfusion time (20 min), impacting proteins essential for cardiac contraction. A second wave, characterized by irreversible oxidation on different residues and reversible Cys oxidation, occurred at late stages (6-12 h), affecting mitochondrial, sarcomere, and inflammation-related proteins. Ischemic preconditioning mitigated the I/R damage caused by the late oxidative wave. In the mouse model, the two-phase pattern of oxidative damage was replicated, and neutrophil depletion mitigated the late wave of I/R-related damage by preventing both Cys reversible oxidation and irreversible oxidation. Altogether, these data identify protein PTMs occurring late after reperfusion as an actionable therapeutic target to reduce the impact of I/R injury.

Absence of Myocardial Involvement After SARS-CoV-2 Vaccination in Asymptomatic Adolescents.

This study aimed to evaluate the presence of subclinical myocardial damage in adolescents who were vaccinated against SARS-CoV-2. One hundred twenty asymptomatic adolescents with a mean age of 16.0 ± 0.4 years (51% girls) underwent cardiac magnetic resonance (CMR) imaging. SARS-CoV-2 IgG/IgM antibody testing was performed, and self-reported dates of confirmed SARS-CoV-2 infection and/or vaccination were collected. Participants were classified according to SARS-CoV-2 status as naïve (non-infected and unvaccinated, n = 74), infected (unvaccinated, n = 23), and vaccinated (independently of past infection status, n = 23). Biventricular volumes and ejection fraction and myocardial T2 relaxation time were similar in the three groups. T1 relaxation time was slightly higher in vaccinated adolescents (1249 ± 35 ms) than in naïve and infected participants (1231 ± 30 ms and 1227 ± 29 ms, respectively; p = 0.035), although this difference was considered clinically irrelevant. This observational study found no evidence of relevant subclinical myocardial involvement after SARS-CoV-2 vaccination in asymptomatic adolescents.

Early insulin resistance in normoglycemic low-risk individuals is associated with subclinical atherosclerosis.

BACKGROUND: Elevated glycated hemoglobin (HbA1c) is associated with a higher burden of subclinical atherosclerosis (SA). However, the association with SA of earlier insulin resistance markers is poorly understood. The study assessed the association between the homeostatic model assessment of insulin resistance index (HOMA-IR) and SA in addition to the effect of cardiovascular risk factors (CVRFs) in individuals with normal HbA1c. METHODS: A cohort of 3,741 middle-aged individuals from the Progression of Early Subclinical Atherosclerosis (PESA) study with basal HbA1c < 6.0% (< 42 mmol/mol) and no known CV disease underwent extensive imaging (multiterritorial vascular ultrasound and coronary artery calcium score, CACS) to assess the presence, burden, and extent of SA. RESULTS: Individuals with higher HOMA-IR values had higher rates of CVRFs. HOMA-IR showed a direct association with the multiterritorial extent of SA and CACS (p < 0.001) and with global plaque volume measured by 3-dimensional vascular ultrasound (p < 0.001). After adjusting for key CVRFs and HbA1c, HOMA-IR values ≥ 3 were associated with both the multiterritorial extent of SA (odds ratio 1.41; 95%CI: 1.01 to 1.95, p = 0.041) and CACS > 0 (odds ratio 1.74; 95%CI: 1.20 to 2.54, p = 0.004), as compared with the HOMA-IR < 2 (the reference HOMA-IR category). In a stratified analysis, this association remained significant in individuals with a low-to-moderate SCORE2 risk estimate (75.6% of the cohort) but not in high-risk individuals. CONCLUSIONS: The use of HOMA-IR identified low-risk individuals with a higher burden of SA, after adjusting for the effects of key traditional CVRFs and HbA1c. HOMA-IR is a simple measure that could facilitate earlier implementation of primary CV prevention strategies in clinical practice.

Metabolic syndrome, adiposity, diet, and emotional eating are associated with oxidative stress in adolescents.

Background: Metabolic syndrome (MS), a condition related to adiposity and oxidative stress, can develop in adolescence, a critical stage in life that impacts health in adulthood. However, there is scarce scientific research about the relationship between lifestyle factors, emotion management, and oxidative stress in this phase of life. Aim: To analyze whether nutritional parameters, lifestyle factors, emotion management, and MS in adolescents are associated with oxidative stress measured by the biomarker 8-isoprostane. Methods: A cross-sectional study was carried out in 132 adolescents (48.5% girls, aged 12 ± 0.48 years) and data were collected on nutritional parameters (anthropometric measurements, biochemical analyzes, and blood pressure), lifestyle factors (physical activity, sleep, and diet), and emotion management (self-esteem, emotional eating, and mood). 8-isoprostane was analyzed in spot urine samples. The study population was categorized in three groups (healthy, at-risk, and with MS) using the International Diabetes Federation definition of MS in adolescents. To capture more complex interactions, a multiple linear regression was used to analyze the association between 8-isoprostane and the aforementioned variables. Results: Urinary 8-isoprostane levels were significantly higher in the MS group compared to the healthy group (1,280 ± 543 pg./mg vs. 950 ± 416 pg./mg respectively). In addition, univariable analysis revealed positive significant associations between 8-isoprostane and body mass index, waist circumference, waist-to-height ratio, body fat percentage, blood lipid profile and glucose, emotional eating, and refined cereal intake. Conversely, a negative significant association was found between 8-isoprostane and sleep duration and fish intake. The multiple linear regression analysis revealed associations between 8-isoprostane and LDL-c (ß = 0.173 value of p = 0.049), emotional eating (low ß = 0.443, value of p = 0.036; high ß = 0.152, value of p = 0.470), refined cereal intake (ß =0.191, value of p = 0.024), and fish intake (ß = -0.187, value of p = 0.050). Conclusion: The MS group, LDL-c, emotional eating, and high refined cereals and low fish intakes were associated with higher levels of oxidative stress in an adolescent population.

Clustering of lifestyle behaviors and adiposity in early adolescents in Spain: findings from the SI! Program for Secondary Schools.

BACKGROUND: Several unhealthy lifestyle behaviors in adolescence are often linked to overweight/obesity. Some of them may be present simultaneously, leading to combined effects on health. Therefore, the clustering of several unhealthy behaviors in adolescents might be associated with adiposity excess. PURPOSE: To identify lifestyle patterns and analyze their association with adiposity in early adolescents. METHODS: A cross-sectional cluster analysis was performed in 1183 adolescents (50.5% girls) with a mean age of 12.5 (0.4) years included in the SI! Program for Secondary Schools in Spain to identify lifestyle patterns based on healthy diet, step counts, sleep time, and leisure screen time. Generalized mixed models were applied to estimate the association between lifestyle patterns and adiposity indices. RESULTS: Four lifestyle patterns were derived: Cluster 1-higher screen time and poorer diet (n = 213), Cluster 2-lower activity and longer sleepers (n = 388), Cluster 3-active and shorter sleepers (n = 280), and Cluster 4-healthiest (n = 302). Except for the number of steps (12,008 (2357) day), the lifestyle behaviors in our sample presented levels far below the recommendations, especially for sleep duration. Cluster 4 included the largest proportion of adolescents from high socioeconomic status families (47.7%) and the lowest prevalence of overweight/obesity (23.1%). Compared to Cluster 4-healthiest, adolescents in the remaining clusters presented a higher prevalence of overweight/obesity and central obesity, showing Cluster 3 the highest prevalences (PR:1.31 [95%CI: 1.31, 1.31] and PR:1.40 [95%CI: 1.33, 1.47]). CONCLUSIONS: Clustering of lifestyle patterns in early adolescence allows the identification of individuals with excess adiposity, in whom health promotion strategies should be stressed, especially in socioeconomically disadvantaged groups. TRIAL REGISTRATION: Clinical Trial Registry, NCT03504059. Registered 20/04/2018-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03504059 .

School-Based Cardiovascular Health Promotion in Adolescents: A Cluster Randomized Clinical Trial.

Importance: School-based interventions offer an opportunity for health promotion in adolescence. Objective: To assess the effect of 2 multicomponent educational health promotion strategies of differing duration and intensity on adolescents' cardiovascular health (CVH). Design, Setting, and Participants: The SI! Program for Secondary Schools is a 4-year cluster randomized clinical intervention trial conducted in 24 secondary schools from Barcelona and Madrid, Spain, from September 7, 2017, to July 31, 2021. Eligible participants were adolescents enrolled in the first grade of secondary school. Interventions: Schools and their participants were randomized to receive a health promotion intervention (SI! Program) over 4 school years (long-term intervention [LTI], 8 schools, 412 adolescents) or 2 school years (short-term intervention [STI], 8 schools, 504 adolescents) or to receive the standard curriculum (control, 8 schools, 441 adolescents). Main outcome and Measures: The primary end point was the between-group difference at 2 and 4 years in the change from baseline of the overall CVH score, as defined by the American Heart Association (range, 0-14 points, with a higher score indicating a healthier CVH profile). Intervention effects were tested with multilevel mixed-effects models. A complete-case intention-to-treat analysis was performed as the primary analysis. Results: Of the randomized students, the study enrolled 1326 adolescents (684 [51.6%] boys, mean [SD] age, 12.5 [0.4] years at recruitment) with a study completion rate of 86.0%. Baseline overall CVH scores were 10.3 points in the LTI group, 10.6 points in the STI group, and 10.5 points in the control group. After 2 years, at halfway through the LTI and at the end of the STI, the difference in the CVH score change was 0.44 points (95% CI, 0.01-0.87; P = .04) between the LTI group and the control group and 0.18 points (95% CI, -0.25 to 0.61; P = .39) between the STI group and the control group. At 4 years, differences for the LTI and STI groups vs control were 0.12 points (LTI: 95% CI, -0.19 to 0.43; P = .42) and 0.13 points (STI: 95% CI, -0.17 to 0.44; P = .38). No adverse events were reported. Conclusions and Relevance: Overall, the tested school-based health promotion strategies in this randomized clinical trial had a neutral effect on the CVH of the adolescents. Although there was evidence of a marginal beneficial effect at a point halfway through implementation in the LTI group, such a benefit was not noted at 4 years. Further research is warranted into the efficacy of school-based health promotion programs. Trial Registration: ClinicalTrials.gov Identifier: NCT03504059.

Sleep duration and its association with adiposity markers in adolescence: a cross-sectional and longitudinal study.

AIMS: Large studies linking adolescents' objectively measured sleep duration and adiposity markers are lacking. We characterized sleep duration and its cross-sectional and longitudinal associations with adiposity markers in adolescence. METHODS AND RESULTS: Seven-day accelerometry was performed in a cohort of adolescents enrolled in the SI! Program for Secondary Schools trial in Spain at approximately ages 12 (1216 adolescents, 49.6% girls), 14 (1026 adolescents, 51.3% girls), and 16 (872 adolescents, 51.7% girls) years. Participants were classified as very short sleepers (VSS; <7 h), short sleepers (SS; 7-<8 h), or recommended-time sleepers (RTS; 8-10 h). Adjusted associations between sleep duration and adiposity markers were analysed using generalized linear and Poisson models. At ∼12 years, 33.7% of adolescents met sleep recommendations, and this percentage decreased with advancing age (22.6% at ∼14 and 18.7% at ∼16 years). Compared with RTS, overweight/obesity prevalence ratios at ∼12, 14, and 16 years among SS were 1.19 [95% confidence interval (CI): 1.09-1.30], 1.41 (95% CI: 1.34-1.48), and 0.99 (95% CI: 0.77-1.26) and among VSS were 1.30 (95% CI: 1.28-1.32), 1.93 (95% CI: 1.41-2.64), and 1.32 (95% CI: 1.26-1.37). Compared with adolescents who always met sleep recommendations, the prevalence of overweight/obesity was ∼5 times higher in those never meeting recommendations or meeting them only once. Similar trends were observed for the waist-to-height ratio (P = 0.010) and fat mass index (P = 0.024). CONCLUSION: Most adolescents did not meet sleep recommendations. Shorter sleep duration was independently associated with unfavourable adiposity markers, and such adverse impact was cumulative. Health promotion programmes should emphasize the importance of good sleep habits.

This study used a wearable activity tracker to analyse sleep patterns and their association with adiposity markers in a large cohort of adolescents at ages 12, 14, and 16 years.At 12 years, only 34% of adolescents met sleep recommendations (eight or more hours of sleep per day), and this percentage decreased with advancing age (23% at 14 and 19% at 16 years). Adolescents sleeping <8 h a day were more likely to present overweight, obesity, or other adverse adiposity markers than their peers with sufficient sleep.The link between insufficient sleep and adverse adiposity markers was independent of energy intake and physical activity levels, indicating that sleep itself is important. Therefore, health promotion programmes for adolescents should emphasize the importance of good sleep habits.

Body image and dietary habits in adolescents: a systematic review.

CONTEXT: Adolescence is a critical developmental stage in which increasing concerns about body image (BI) coincide with the consolidation of dietary habits (DHs). Multiple studies have sought robust associations between BI and DHs to prevent unhealthy behaviors. OBJECTIVE: The aim of this systematic review was to examine the available literature on the association between BI perception (BIP) and/or satisfaction (BIS) and DHs in adolescents. DATA SOURCES: A search was carried out of 5 electronic databases (PubMed, SciELO, Cochrane, Embase, and PsycInfo) using a combination of keywords (and synonyms) related to adolescence, BI, and diet. DATA EXTRACTION: Data screening, extraction, and quality assessment were performed independently by 2 investigators using the PRISMA and AXIS guidelines. DATA ANALYSIS: Of 2496 articles screened, 30 articles, published in English or Spanish, that evaluated the relationship between BI and DHs in adolescents aged between 10 years and 18 years, were included. A relationship between accurate BI perception in adolescents and healthy DHs was reported in 5 articles (16.2%). A relationship between overestimation of body weight in adolescents and healthy DHs was reported in 4 articles (13.3%). A relationship between underestimation of body weight and unhealthy DHs was reported in 8 articles (26.7%). In addition, 4 articles (13.3%) reported a relationship between BIS and healthy DHs. The desire to gain weight was associated with unhealthy DHs in 3 (10%) of the articles, while the desire to lose weight was related to healthy DHs in 3 (10%) of the articles and to unhealthy DHs in 3 (10%) other articles. There were also gender differences in the relationship between BIP or BIS and DHs. CONCLUSION: Adolescents who underestimate their body weight tend to report less healthy DHs than body weight overestimators. Adolescents unsatisfied with their BI and with a drive for thinness frequently engage in DHs linked to losing weight. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42020184625.

Magnetic resonance imaging reference values for cardiac morphology, function and tissue composition in adolescents.

Background: Cardiovascular magnetic resonance (CMR) is a precise tool for the assessment of cardiac anatomy, function, and tissue composition. However, studies providing CMR reference values in adolescence are scarce. We aim to provide sex-specific CMR reference values for biventricular and atrial dimensions and function and myocardial relaxation times in this population. Methods: Adolescents aged 15-18 years with no known cardiovascular disease underwent a non-contrast 3-T CMR scan between March 2021 and October 2021. The imaging protocol included a cine steady-state free-precession sequence for the analysis of chamber size and function, as well as T2-GraSE and native MOLLI T1-mapping for the characterization of myocardial tissue. Findings: CMR scans were performed in 123 adolescents (mean age 16 ± 0.5 years, 52% girls). Mean left and right ventricular end-diastolic indexed volumes were higher in boys than in girls (91.7 ± 11.6 vs 78.1 ± 8.3 ml/m2, p < 0.001; and 101.3 ± 14.1 vs 84.1 ± 10.5 ml/m2, p < 0.001), as was the indexed left ventricular mass (48.5 ± 9.6 vs 36.6 ± 6.0 g/m2, p < 0.001). Left ventricular ejection fraction showed no significant difference by sex (62.2 ± 4.1 vs 62.8 ± 4.2%, p = 0.412), whereas right ventricular ejection fraction trended slightly lower in boys (55.4 ± 4.7 vs. 56.8 ± 4.4%, p = 0.085). Indexed atrial size and function parameters did not differ significantly between sexes. Global myocardial native T1 relaxation time was lower in boys than in girls (1215 ± 23 vs 1252 ± 28 ms, p < 0.001), whereas global myocardial T2 relaxation time did not differ by sex (44.4 ± 2.0 vs 44.1 ± 2.4 ms, p = 0.384). Sex-stratified comprehensive percentile tables are provided for most relevant cardiac parameters. Interpretation: This cross-sectional study provides overall and sex-stratified CMR reference values for cardiac dimensions and function, and myocardial tissue properties, in adolescents. This information is useful for clinical practice and may help in the differential diagnosis of cardiac diseases, such as cardiomyopathies and myocarditis, in this population. Funding: Instituto de Salud Carlos III (PI19/01704).

Urinary Nitric Oxide Levels Are Associated with Blood Pressure, Fruit and Vegetable Intake and Total Polyphenol Excretion in Adolescents from the SI! Program.

Nitric oxide (NO) is important to cardiovascular health (CVH), and its bioavailability could be regulated by the antioxidant effect of polyphenols, improving endothelial function and consequently blood pressure (BP). However, scant research has been carried out on NO and CVH correlates in adolescent populations. Therefore, our aim was to investigate the association between NO and the CVH status and other health factors in adolescents. NO, total polyphenol excretion (TPE), anthropometric measurements, BP, blood lipid profile, blood glucose, diet, physical activity, and smoking status were recorded, while CVH score was classified as ideal, intermediate, and poor. Negative associations were observed between NO and body mass index, body fat percentage, BP, and triglycerides; and positive associations between NO and skeletal muscle percentage, HDL-cholesterol, fruit and vegetable intake, and TPE was observed. To capture more complex interactions among different factors, multiple linear regression was performed, obtaining a significant association between NO and fruit and vegetable intake (ß = 0.175), TPE (ß = 0.225), and systolic BP (ß = -0.235). We conclude that urinary NO levels are positively associated with the consumption of fruits and vegetables rich in antioxidants such as polyphenols and negatively associated with systolic BP.