Evaluation of the Association between Blood Pressure and Birth Weight: A Cross-Sectional Study on 600 Outpatient Children

Background: Despite the declining global prevalence of preterm birth, it accounts for a certain proportion of births in developing countries. Those born earlier, are prone to have lower birth weight (BW), smaller kidneys, lower glomerular filtration rate, higher blood pressure (BP) and overall poorer future cardio-metabolic health outcomes. MethodsThe current cross-sectional study was conducted on relatively healthy individuals aged 3-18 years with no PMH of any specific diseases, and not in toxic or ill condition. Recruitment was in 2 phases for the participants with high BP at the first visit (regarding a 2-week follow-up BP assessment) and in 1 phase for the normotensive participants.ResultsAmong the total 600 participants, the prevalence of elevated BP, grade 1 hypertension (HTN), and grade 2 HTN was 5.2, 5.5, and 2.3%, respectively. The prevalence of children with very low birth weight, low birth weight, and high birth weight was 1.7, 8.7, and 4.5%, respectively. Chi-square analysis showed no statistically significant association between BW and BP (P-value=0.774). There was a statistically significant association between BP and height, weight, and heart rate (HR) (P-value<0.05). ConclusionsThere is no statistically significant interaction between BP and BW. The association illustrated by previous studies may be caused by other underlying factors including weight or by methodological limitations including nor follow-up BP assessment, neither excluding ill, toxic, and hospitalized children. There is a direct relationship between BP and HR, weight, and height. However, the relationship between BP and the two latter is inverted for BP above grade 2 HTN.Trial RegistrationDesign of the current study was approved by the ethics committee of the Research Institute for Arak University of Medical Sciences. Ethics Code: IR.ARAKMU.REC.1400.271