Urban-rural disparity in blood pressure among Chinese children: 1985-2010.

Abstract

Understanding the urban-rural gap in childhood blood pressure (BP) is crucial to alleviate the urban-rural disparity in burden of hypertension in the future. This study investigated trends in urban-rural BP disparity and the influence of body mass index among Chinese children between 1985 and 2010. Data included 1 010 153 children aged 8-17 years enrolled in the Chinese National Survey on Students' Constitution and Health, a successive national cross-sectional survey. High BP was defined according to age-sex- and height-specific 95th percentile. Multi-variable linear and logistic regression models were used to assess the urban-rural BP differentials. Although urban children had greater prevalence of overweight and obesity than rural counterparts, rural children revealed higher levels of BP across the consecutive 25-year periods. The urban-rural disparity in prevalence of high systolic BP decreased from 2.3 (95% confidence interval: 2.3, 2.6) % to 0.2 (-0.1, 0.4) % in boys and 3.7 (3.5, 4.0) % to 0.6 (0.3, 0.8) % in girls between 1985 and 2010 after adjusting for confounding factors. Further adjustment of body mass index did not change the urban-rural disparity and its trend. The similar results were also observed for diastolic BP. Despite the urban-rural disparity in BP decreased between 1985 and 2010, rural children constantly showed higher BP levels than their urban counterparts. Since these differentials in BP cannot be explained by obesity, study of other potential factors could provide further opportunity to bridge this gap.