Associations of social and economic and pregnancy exposures with blood pressure in UK White British and Pakistani children age 4/5

Abstract

South Asians have higher rates of coronary heart disease (CHD) than White European individuals. Blood pressure (BP) is one of the most important risk factors for CHD and ethnic differences in BP have been identified in childhood. Early life exposures could explain some of these differences. We examined associations of family social and economic and maternal pregnancy exposures and BP at age 4/5 in 1644 White British and 1824 Pakistani mother-offspring pairs from the Born in Bradford study. We found that systolic BP was similar but diastolic BP was higher, in Pakistani compared to White British children (adjusted mean differences were −0.170 mmHg 95% CI −0.884, 0.543 for systolic BP; 1.328 mmHg 95% CI 0.592, 2.064 for diastolic BP). Social and economic exposures were not associated with BP in either ethnic group. Maternal BMI was positively associated with BP in both groups but this association was mediated by child BMI. Only gestational hypertension was associated with child systolic and diastolic BP and this was only identified in Pakistani mother-offspring pairs. These findings suggest that Pakistani populations may have a different BP trajectory compared to White British groups and that this is already evident at age 4/5 years.

Growing up in Bradford: protocol for the age 7–11 follow up of the Born in Bradford birth cohort

“…By age 4-5 years, the positive effect of maternal gestational hyperglycaemia seems to have attenuated, though greater maternal early pregnancy adiposity remains associated with greater offspring adiposity at this age [5]. We have also shown that Pakistani women are less likely to experience hypertensive disorders of pregnancy (HDP) compared to white British women, but that HDP is more robustly associated with offspring BP at age 4-5 years in Pakistani compared to white British children [4].…”

“…Follow-up since then has included growth and blood pressure measures by primary school nurses at age 5-6, [4,5] whole cohort record-linkage to health and educational data, e.g. [6,7], detailed bespoke data collection with sub-samples [8][9][10], and addition of biomarker data using stored biological samples, including genome-wide data, metabolomic data and Deoxyribonucleic acid (DNA) methylation [11,12].…”

“…Analysis of BiB data has provided insights into the factors that affect health and wellbeing in pregnancy and early childhood, including on social and ethnic inequalities in health [14][15][16], the relationships between maternal gestational adiposity, gestational diabetes mellitus (GDM) and maternal circulating glucose concentrations and fetal growth, birth outcomes, infant and childhood health in South Asian and White European families [4,5,[17][18][19], the associations of environmental stressors such as green space and air pollution on health e.g. [20][21][22], exposures that may influence development of asthma and allergies [23] and the role of genetic variation in human health [12].…”

“…3 Offered as an option if participant does not want a blood sample to be taken. 4 For subsample of children in sub-study on renal function only. 5 For subsample only Table 1).…”

“…baseline) data from BiB have compared associations between either White British and Pakistani (see for e.g. [4,5,17]) or White European and South Asian (e.g. [19]) and the objectives demonstrate that future studies are also likely to compare these groups.…”