Static cut-points of hypertension and increased arterial stiffness in children and adolescents: The International Childhood Vascular Function Evaluation Consortium.

Pediatric elevated blood pressure (BP) and hypertension are usually defined using traditional BP tables at the 90th and 95th percentiles, respectively, based on sex, age, and height, which are cumbersome to use in clinical practice. The authors aimed to assess the performance of the static cut-points (120/80 mm Hg and 130/80 mm Hg for defining elevated BP and hypertension for adolescents, respectively; and 110/70 mm Hg and 120/80 mm Hg for children, respectively) in predicting increased arterial stiffness. Using data from five population-based cross-sectional studies conducted in Brazil, China, Korea, and New Zealand, a total of 2546 children and adolescents aged 6-17 years were included. Increased arterial stiffness was defined as pulse wave velocity ≥sex-specific, age-specific, and study population-specific 90th percentile. Compared to youth with normal BP, those with hypertension defined using the 2017 American Academy of Pediatrics guideline (hereafter referred to as "percentile-based cut-points") and the static cut-points were at similar risk of increased arterial stiffness, with odds ratios and 95% confidence intervals of 2.35 (1.74-3.17) and 3.07 (2.20-4.28), respectively. Area under the receiver operating characteristic curve and net reclassification improvement methods confirmed the similar performance of static cut-points and percentile-based cut-points (P for difference > .05). In conclusion, the static cut-points performed similarly well when compared with the percentile-based cut-points in predicting childhood increased arterial stiffness. Use of static cut-points to define hypertension in childhood might simplify identification of children with abnormal BP in clinical practice.

Exploring the relationship of peripheral total bilirubin, red blood cell, and hemoglobin with blood pressure during childhood and adolescence / Explorando a relação entre os níveis periféricos de bilirrubina total, glóbulos vermelhos e hemoglobina e a pressão arterial na infância e adolescência

Abstract Objective: Total bilirubin is beneficial for protecting cardiovascular diseases in adults. The authors aimed to investigate the association of total bilirubin, red blood cell, and hemoglobin levels with the prevalence of high blood pressure in children and adolescents. Methods: A total of 3776 students (aged from 6 to 16 years old) were examined using cluster sampling. Pre-high blood pressure and high blood pressure were respectively defined as the point of 90th and 95th percentiles based on the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents. Both systolic and diastolic blood pressure were standardized into z-scores. Results: Peripheral total bilirubin, red blood cell and hemoglobin levels were significantly correlated with age, and also varied with gender. Peripheral total bilirubin was negatively correlated with systolic blood pressure in 6- and 9-year-old boys, whilst positively correlated with diastolic blood pressure in the 12-year-old boys and 13- to 15-year-old girls (p < 0.05). Higher levels of red blood cell and hemoglobin were observed in pre-high blood pressure and high blood pressure students when compared with their normotensive peers (p < 0.01). The increases in red blood cell and hemoglobin were significantly associated with high blood pressure after adjusting for confounding factors. The ORs (95% CI) of each of the increases were 2.44 (1.52-3.92) and 1.04 (1.03-1.06), respectively. No statistical association between total bilirubin and high blood pressure was observed (p > 0.05). Conclusion: Total bilirubin could be weakly correlated with both systolic and diastolic blood pressure, as correlations varied with age and gender in children and adolescents; in turn, the increased levels of red blood cell and hemoglobin are proposed to be positively associated with the prevalence of high blood pressure.

Resumo Objetivo: A bilirrubina total é benéfica para proteger contra doenças cardiovasculares em adultos. Nosso objetivo foi investigar a associação dos níveis de bilirrubina total, glóbulos vermelhos e hemoglobina com a prevalência de pressão arterial elevada em crianças e adolescentes. Métodos: Um total de 3.776 estudantes (com idade entre 6-16 anos) foram examinados utilizando uma amostra em blocos. A pressão arterial elevada anterior e a pressão arterial elevada foram definidas como o 90° e 95° percentil, respectivamente, com base nos critérios do Quarto Relatório sobre Diagnóstico, Avaliação e Tratamento da Pressão Arterial elevada em Crianças e Adolescentes. A pressão arterial sistólica e pressão arterial diastólica foram padronizadas no escore z. Resultados: Os níveis periféricos de bilirrubina total, glóbulos vermelhos e hemoglobina foram significativamente correlacionados à idade, que também variou de acordo com o sexo. A bilirrubina total periférica apresentou uma correlação negativa com a pressão arterial sistólica em meninos com 6 e 9 anos, ao passo que apresentou uma correlação positiva com a pressão arterial diastólica em meninos de 12 anos e meninas de 13 a 15 anos (p < 0,05). Foram observados níveis mais elevados de glóbulos vermelhos e hemoglobina em estudantes com pressão arterial elevada anterior e pressão arterial elevada em comparação a indivíduos normotensos (p < 0,01). Os aumentos de glóbulos vermelhos e hemoglobina tiveram uma associação significativa com a pressão arterial elevada após ajuste dos fatores de confusão. As RC (IC de 95%) de cada um dos aumentos foram 2,44 (1,52-3,92) e 1,04 (1,03-1,06) respectivamente. Não foi observada nenhuma associação estatística entre o nível de bilirrubina total e a pressão arterial elevada (p > 0,05). Conclusão: A bilirrubina total pode ter correlações fracas com a pressão arterial sistólica e a pressão arterial diastólica, variando de acordo com a idade e o sexo em crianças e adolescentes, enquanto isso, propõe-se que o aumento dos níveis de glóbulos vermelhos e hemoglobina está positivamente associado à prevalência de pressão arterial elevada.

Exploring the relationship of peripheral total bilirubin, red blood cell, and hemoglobin with blood pressure during childhood and adolescence.

OBJECTIVE: Total bilirubin is beneficial for protecting cardiovascular diseases in adults. The authors aimed to investigate the association of total bilirubin, red blood cell, and hemoglobin levels with the prevalence of high blood pressure in children and adolescents. METHODS: A total of 3776 students (aged from 6 to 16 years old) were examined using cluster sampling. Pre-high blood pressure and high blood pressure were respectively defined as the point of 90th and 95th percentiles based on the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents. Both systolic and diastolic blood pressure were standardized into z-scores. RESULTS: Peripheral total bilirubin, red blood cell and hemoglobin levels were significantly correlated with age, and also varied with gender. Peripheral total bilirubin was negatively correlated with systolic blood pressure in 6- and 9-year-old boys, whilst positively correlated with diastolic blood pressure in the 12-year-old boys and 13- to 15-year-old girls (p<0.05). Higher levels of red blood cell and hemoglobin were observed in pre-high blood pressure and high blood pressure students when compared with their normotensive peers (p<0.01). The increases in red blood cell and hemoglobin were significantly associated with high blood pressure after adjusting for confounding factors. The ORs (95% CI) of each of the increases were 2.44 (1.52-3.92) and 1.04 (1.03-1.06), respectively. No statistical association between total bilirubin and high blood pressure was observed (p>0.05). CONCLUSION: Total bilirubin could be weakly correlated with both systolic and diastolic blood pressure, as correlations varied with age and gender in children and adolescents; in turn, the increased levels of red blood cell and hemoglobin are proposed to be positively associated with the prevalence of high blood pressure.