Retrospective and longitudinal study of blood pressure in school-aged children

BACKGROUND: Pediatric hypertension (HTN) is increasing over time. Worldwide, the blood pressure (BP) trend has been poorly studied. The aim of our study is to evaluate the recent trend in BP in a school-aged children sample, and to search for factors that might influence BP variability. MATERIALS AND METHODS: This is a retrospective longitudinal analysis studying the BP of school-aged children covering the classes of 2013-2021. From medical records of the children, sex, date of birth, date of medical visit which takes place every two years (in the 6th, 8th, and 10th grade), height (in cm), weight (in kg), systolic blood pressure (SBP), and diastolic blood pressure (DBP), were collected for each child. RESULTS: The sample consisted of 2164 children. SBP and DBP were significantly lower in girls than in boys and were significantly correlated with body mass index (BMI) (p-value <0.001 for all comparisons). A significant increase in SBP and DBP was observed from the 6th to the 10th grade, as well as a significant decrease of BP during a nine-year follow-up (p-values <0.001 for all comparisons). CONCLUSION: Our results confirmed a sex difference in BP, an increase in BP with age and a positive association between BMI and BP. Finally, a negative secular trend for BP was found. Further studies are needed to determine if this decrease in BP with time will persist after the coronavirus disease 19 pandemic.