The relationship between sitting height, sitting height to height ratio with blood pressure among Polokwane private school children aged 6–13 years

Abstract

Background: It is notable that sitting height (SH) correlates with blood pressure (BP) in children and adolescents of developed countries. However, little is known about the relationships between SH and SH to height ratio (SH/H) with BP in South African children from middle and upper socio-economic groups. The purpose of this study was to compare SH and SH/H of private school attending children in the Polokwane area with National Health and Nutrition Examination Survey III (NHANES III) reference population and to determine the relationship between SH, SH/H with BP among private school attending children. Methods: A total of 1665 children (846 boys and 819 girls) aged between 6 and 13 years attending three private schools in Polokwane, underwent anthropometric and BP measurements using standard procedures. Linear regression was used to determine the relationship between height, SH, SH/H with BP among these children. Results: Polokwane private school attending boys from age 7 to 13 years displayed a lower mean SH compared to the NHANES III whereas NHANHES III girls from age 10 to 13 years had a higher mean SH compared to those in private school. In the simple regression analysis, SH was positively associated with SBP (β =1.318; 95% CI = 1.217-1. 418) and DBP (β = 0.641; 95% Cl = 0.555-0.727). The findings remains statistically significant only for SH with both SBP (β = 1.025; 95% Cl = 0.844-1.201) and DBP (β = 0.585; 95% Cl 0.434-0.736) after adjusting for age, gender and BMI among these children. Conclusion: In South African children, SH and SH/H were lower compared to the NHANES III children. There was a significant positive association between DBP and SBP together with the components of height among Polokwane private school children.

The Contribution of Linear Growth Components to Hypertension in Secondary School Adolescents in an Urban Setting in Cameroon

“…Greater height, SH and SH/H in children and adolescents have been shown to positively influence blood pressure. Studies performed in China [17], Brazil [19] and rural South Africa [21] indicated that height, SH and SH/H ratio are associated with blood pressure. This is in line with our study, where it was observed that height, SH and SH/H were significantly associated with SBP in the unadjusted analysis, and height alone was significantly associated with SBP in the adjusted analysis.…”

“…among Brazilian [19], South African [21] and Indian [25] children found that SH was associated with BP. Furthermore, a study by Dong et al [17] in Chinese children and adolescents found that SH correlated positively with BP.…”

“…Evidence suggests that in children and adolescents being taller is associated with high BP [17] [18] [19]. However, there are only a few studies that have studied the effect of the components of height on blood pressure in the paediatric population [18] [19] [20] [21]. In addition, components of height which are key in the assessment of linear growth, have been found to be positively associated with high blood pressure in children and adolescents [19] [20] [21].…”

“…However, there are only a few studies that have studied the effect of the components of height on blood pressure in the paediatric population [18] [19] [20] [21]. In addition, components of height which are key in the assessment of linear growth, have been found to be positively associated with high blood pressure in children and adolescents [19] [20] [21]. For instance, children with a higher height-for-age tend to accumulate more adiposity [22], a risk factor for elevated BP in this group.…”

Widespread kidney anomalies in children with Down syndrome

“…But, given the shorter stature of individuals with Down syndrome, it is possible that we underestimated their blood pressure in contrast to the controls. However, trunk size is the main determinant of blood pressure association with height, as opposed to leg length [51,52], and since trunk size is fairly similar in Down syndrome compared to healthy controls (i.e., shorter leg length is primary cause of shorter stature in Down syndrome), underestimation of blood pressure in our cases is likely minimal [53,54]. We used the Schwartz formula to estimate GFR in our participants with Down syndrome, which may decrease the accuracy of the eGFR in Down syndrome, as creatinine production may be altered [55].…”