Sex difference in blood pressure among South Asian diaspora in Europe and North America and the role of BMI: a meta-analysis.

It is unclear whether the sex difference that is known to occur in blood pressure (BP) is similar in some South Asian populations. This study presents a meta-analysis of the sex difference in BP, hypertension and the role of body mass index (BMI) in South Asian diaspora compared with populations of European descent. We systematically searched for studies that reported BP and hypertension among South Asian descent populations living in Europe and North America. Weighted mean differences in BP and risk ratios (RR) for hypertension were calculated for men and women. We included 11 studies in this meta-analysis. In general, men had a higher BP and prevalence of hypertension than women, for example, systolic BP was higher in men than in women among the Indian (7.21 mm Hg, 95% confidence interval (CI): 4.46-9.95) and European populations (6.12 mm Hg, 95% CI: 4.45-7.80). The difference was less in the Pakistani population (4.00 mm Hg, 95% CI: 2.65-5.36). The Bangladeshi population showed a comparatively small sex difference in systolic (2.93 mm Hg, 95% CI: 1.20-4.66) and diastolic BP (0.68 mm Hg, 95% CI: -1.76 to 3.12) and prevalence of hypertension (RR 1.28, 95% CI: 0.66-2.46). Sex differences in BMI for the South Asian populations were greater than those in Europeans. The Indian population had similar sex differences in BP and hypertension compared with Europeans, but Pakistani and Bangladeshi had smaller sex differences. Sex differences in BMI might relate to the blunted sex differences in BP in Pakistani and Bangladeshi populations. Further research should focus on factors that underlie this intriguing sex difference among South Asian populations.