A sex-related mediating effect of uric acid in the association between body composition and blood pressure in children and adolescents.

The increase in blood pressure (BP) during somatic growth might have direct determinants but also mediating factors. We investigated whether uric acid (UA) and other metabolic factors would mediate the association between body composition components and BP. A cross-sectional study was conducted in 928 children and adolescents (aged 6-18 years), in which body composition and blood biochemistry were evaluated. Structural equation modeling was performed to test the direct and indirect pathways between systolic blood pressure (SBP) and body composition parameters. Muscle mass (MM) showed a strong direct effect on BP, regardless of sex. In girls, a mediating pathway through UA was not significant, but the association between fat mass (FM) and MM with SBP was mediated by the cluster of metabolic factors. In boys, both MM and FM were associated with SBP through a mediating pathway via UA, but not via the cluster of metabolic factors. The association between body composition and BP in children and adolescents has a complex design and also has a sex-specific mediating component. The increase in the UA levels may affect BP levels early in boys. Also, metabolic changes elicited by FM contribute to the increase in BP at an early age in girls. Novelty: MM showed a strong direct effect on BP, regardless of sex. In girls, the association between FM and MM with SBP was mediated by the cluster of metabolic factors. In boys, both MM and FM were associated with SBP through a mediating pathway via UA.

Percentage of energy contribution according to the degree of industrial food processing and associated factors in adolescents (EVA-JF study, Brazil).

OBJECTIVE: To evaluate energetic contribution according to the degree of industrial food processing and its association with sociodemographic, anthropometric, biochemical, clinical and behavioural characteristics in adolescents. DESIGN: Cross-sectional study (Adolescent Lifestyle Study). Food consumption was assessed using 24-h dietary recalls, with foods classified by degree of industrial progressing. The usual diet was estimated using the Multiple Source Method. In a linear regression model, the energy percentage (E %) was associated with sociodemographic, anthropometric, biochemical, clinical and behavioural characteristics, after adjustment for sex and age. SETTING: Juiz de Fora, Brazil. PARTICIPANTS: Eight hundred and four adolescents, of both sexes, 14-19 years of age, enrolled in public schools. RESULTS: The E % of unprocessed or minimally processed foods corresponded to 43·1 %, processed foods to 11·0 % and the ultraprocessed foods to 45·9 %. E % of unprocessed foods was associated with socio-economic stratum (adjusted ß = -0·093; P = 0·032), neck circumference (adjusted ß = 0·017; P = 0·049), screen time (adjusted ß = -0·247; P = 0·036) and HDL-cholesterol (adjusted ß = -0·156; P = 0·003). E % of ultraprocessed foods was associated with socio-economic stratum (adjusted ß = 0·118; P = 0·011), screen time (adjusted ß = 0·375; P = 0·003), BMI (adjusted ß = -0·029; P = 0·025), neck circumference (adjusted ß = -0·017; P = 0·028) and HDL-cholesterol (adjusted ß = 0·150; P = 0·002). CONCLUSIONS: There was a high E % of ultraprocessed foods in the diet of the adolescents. Actions are needed to raise the awareness of adopting healthy eating habits.

Body image disorders associated with lifestyle and body composition of female adolescents.

OBJECTIVE: To investigate the association between body image disorders and the lifestyle and body composition of female adolescents. DESIGN: Cross-sectional study. SETTING: The Body Shape Questionnaire (BSQ) and Silhouette Scale and Sociocultural Attitudes Towards Appearance Questionnaire-3 were used to evaluate the participants' body image. Body composition was evaluated by a Dual-Energy X-ray Absorptiometry equipment, and lifestyles were identified by latent class analysis (LCA) using the poLCA package for R. PARTICIPANTS: Female adolescents aged 14-19 years old, in the city of Viçosa-MG, Brazil. RESULTS: In total, 405 girls participated in the study. Almost half of the participants were dissatisfied with their current physical appearance (51·4 %), presented body perception distortions (52·9 %). 47·3 % of the adolescents were dissatisfied with their body according to the BSQ, and another 8 % severely so. Subjects with an 'Inactive and Sedentary' latent lifestyle were 1·71 times as likely to feel dissatisfied as those with active and sedentary or inactive and non-sedentary lifestyles (95 % CI 1·08, 2·90, P = 0·047). Body image disorders showed an association with decreased amounts of moderate and vigorous physical activity, high screen time, increased alcohol consumption and excess body fat. CONCLUSIONS: Particular patterns of lifestyle and body composition seem to be associated in female adolescents with dissatisfaction with, distortion of and excessive concern about appearance. Specifically, physical inactivity, sedentary behaviour, alcohol consumption and high body fat percentage may be strongly linked to body image disorders.

Association of uric acid with cardiovascular risk in Brazilian children and adolescents.

BACKGROUND AND AIM: Hyperuricemia in adults is associated with cardiovascular risk factors. However, there is less data regarding this association in children and adolescents. Our purpose was to determine association between serum uric acid (SUA) and cardiovascular risk. METHODS AND RESULTS: A fasting blood sample was collected from 1750 participants aged 6-17 years enrolled in a social project and public schools in Espírito Santo, Brazil. Internal cut-offs were generated to define high SUA (≥90th percentile of SUA concentration for sex and age group). Body mass index percentile (pBMI), body fat percentage (BFP) and muscle mass were determined by bioimpedance. Data are given as mean ± standard deviation. High SUA was associated with overweight/obesity (OR 3.7 CI 95% 2.7-5.0), high waist circumference (WC) (OR 3.9 CI 95% 2.9-5.4), low HDL (OR 2.0 CI 95% 1.5-2.8), high blood pressure (BP) (OR 1.8 CI 95% 1.1-3.2), high BFP (OR 4.1 CI 95% 2.7-6.4), metabolic syndrome (MetS) (OR 3.6 CI 95% 1.8-7.1) and insulin resistance (OR 1.7 CI 95% 1.1-2.7). Individuals in the fourth quartile of SUA, compared to those in the first quartile, showed higher age, pBMI, WC, BFP and muscle mass. Using a reference value of 5.5 mg/dL, the prevalence of hyperuricemia in the sample was 10.3% (CI 95% 8.9-11.7%). CONCLUSION: Higher SUA values are associated with higher cardiovascular risk in childhood and adolescence. The main cardiovascular risk factors associated with hyperuricemia were overweight/obesity, high WC, dyslipidemia, high BFP, high BP, insulin resistance and MetS.