Multifactorial correlates of blood pressure in South Asian children in Canada: a cross-sectional study

Abstract

ObjectiveWe sought to explore various correlates of blood pressure (BP) and hypertension, and to identify the most important aggregate combination of correlates for BP in South Asian children.DesignCross-sectional studySettingCommunity-based recruitment in two Canadian citiesParticipantsSouth Asian children (n=762) provided a range of physiological, lifestyle and social variables. BP was assessed using an automated device. Body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and BP were transformed to z-scores using published standards.Outcome measuresLinear and logistic regression analyses were used to explore associations between the range of variables with BP z-scores and hypertension while stepwise regression was used to identify aggregate factors that provided explanatory capacity for systolic BP (SBP) and diastolic BP (DBP) z-scores.ResultsA range of variables were associated with BP z-score and hypertension in unadjusted analysis. On adjustment for confounders, the association between age (β=−0.054, 95% CI=−0.078 to 0.029), female sex (β=−0.208, 95% CI=−0.350 to –0.067), height (β=0.022, 95% CI=0.011 to 0.033), weight (β=0.047, 95% CI=0.040 to 0.055), BMI z-score (β=0.292, 95% CI=0.249 to 0.336), WC z-score (β=0.273, 95% CI=0.219 to 0.326), WHtR z-score (β=0.289, 95% CI=0.236 to 0.342), heart rate (β=0.016, 95% CI=0.010 to 0.022), child’s perception of body image (β=0.183, 95% CI=0.128 to 0.239) and grip strength (β=0.025, 95% CI=0.007 to 0.043) with SBP z-score remained. In stepwise regression, age, sex, BMI z-score, heart rate and weight accounted for 30% of the variance of SBP z-score, while age, BMI z-score, heart rate and daily fast food intake accounted for 23% of the DBP z-score variance.ConclusionOur findings suggest that variables, such as age, sex, height, adiposity and heart rate, provide stronger explanatory capacity to BP variance and hypertension risk than other variables in South Asian children.