Heterogeneity in blood pressure in UK Bangladeshi, Indian and Pakistani, compared to White, populations: divergence of adults and children.

Blood pressure (BP) and hypertension prevalence differences between UK South Asians (Bangladeshis, Indians and Pakistanis) and White Europeans exist in childhood and adulthood. This meta-analysis sought to quantify these differences. We searched MEDLINE (1946-2017), EMBASE (1974-2017) and GLOBAL HEALTH (1973-2017) for comparative studies and pooled the data with Revman (Cochrane Collaboration). Twenty-two studies were included-fourteen on adults and eight on children. South Asian adults had lower systolic and slightly lower diastolic BP. However, stark heterogeneity existed between South Asian subgroups: Bangladeshis had markedly lower systolic BP (mean difference: -11.7 mmHg in men and women), Indians slightly lower (-2.0 mmHg in men and -4.5 mmHg in women) and Pakistanis intermediately lower (-7.9 mmHg in men and -8.6 mmHg in women), compared to White Europeans. However, South Asian children did not have lower systolic or diastolic BP compared to White children, and their BP was often higher. This intergenerational change in BP difference mirrored the change in body mass index difference, particularly in Bangladeshis. We conclude that ethnicity-related BP differences are heterogeneous and dependent on age, sex and South Asian subgroup. South Asian children do not have lower BP than White Europeans in contrast to their adult counterparts. There is concern that this pattern may continue into adulthood, worsening the already high cardiovascular disease burden in South Asians in future years. Further research is needed to ascertain the causes of this evolving issue.