Prevalence of high blood pressure subtypes and its associations with BMI in Chinese children: a national cross-sectional survey

BACKGROUND: Data on prevalence and characteristics of different high blood pressure subtypes are lacking among Chinese children. Regarding the mechanistic differences between isolated systolic high blood pressure and isolated diastolic high blood pressure and their different impact on end organ diseases, it is necessary to examine the prevalence of different high blood pressure subtypes in Chinese children and explore their associations with adiposity. METHODS: Data were derived from the baseline data of a multi-centered cluster randomized controlled trial involving participants from China. High blood pressure was defined according to age-, gender- and height-specific 95th percentile developed by the National High Blood Pressure Education Program Working Group. Body mass index was used to classify underweight, normal weight, overweight and obesity. RESULTS: The prevalence of HBP was 10.2% and 8.9% for boys and girls, respectively. Isolated systolic high blood pressure is the dominant high blood pressure subtype among Chinese boys aged 6–17 years and girls aged 12–17 years, while isolated diastolic high blood pressure was the most common high blood pressure subtype in girls aged 6–11 years. In boys, the status of overweight doubled the risk of isolated systolic high blood pressure (95% CI, 1.73, 2.31; P < 0.001) compared with the normal weight group, and the risk for obese children was 4.32 (95% CI, 3.81, 4.90; P < 0.001). The corresponding odds ratios in girls were 2.04 (95% CI, 1.68, 2.48, P < 0.001) for overweight, and 4.0 (95% CI, 3.36, 4.76, P < 0.001) for obesity. Similar patterns were also observed in the association between combined systolic and diastolic high blood pressure and adiposity. CONCLUSION: The distribution of high blood pressure subtypes in boys differed from those in girls, and boys with adiposity showed a higher risk of high blood pressure than their female counterpart. Difference in strength of association between isolated diastolic high blood pressure and isolated systolic high blood pressure with body mass index was also found. These results may aid current strategies for preventing and controlling pediatric hypertension. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12889-017-4522-2) contains supplementary material, which is available to authorized users.