Adiposity and blood pressure in South Asian Children and adolescents in Karachi

BackgroundThe association of adiposity during childhood with future risk of elevated blood pressure (BP) in South Asian children is not known. We aimed to investigate the relationship between waist circumference (WC) and body mass index (BMI) with BP over a 2-year period, independent of the baseline BP.MethodsWe analyzed data on children aged 5-14 years who participated in the Control of Blood Pressure and Risk Attenuation (COBRA) trial in Karachi, Pakistan. Separate multivariable models were built for WC and BMI using generalized estimation equations to determine the association between the baseline and changes in adiposity with the primary outcome of increase in systolic BP (SBP) over 2 years of follow-up.ResultsWe assessed 1,675 children 51% were boys. At 2 years, 1,278 (76.5%) were available for follow-up. On multivariate analysis, WC at baseline (Β (95% confidence interval (CI))) = (0.20 (0.13, 0.29), for each 1cm increase) and change in WC from baseline to follow-up (0.24 (0.16, 0.34), for each 1cm increase) were associated with increase in SBP. Similarly BMI at baseline (0.54 (0.33, 0.75) and change in BMI 1.32 (1.06, 1.59), for each 1kg/m 2 increase) were associated with change in SBP. Categorical expression of adiposity yielded consistent results. ConclusionsBaseline adiposity and increase in adiposity, both, are associated with increase in BP, independent of the baseline level of BP in South Asian children. Both WC and BMI can be used to identify children at high risk of increase in BP.