National, regional and provincial prevalence of childhood hypertension in China in 2020: a systematic review and modelling study.

Background: Childhood hypertension is a growing health concern in China. Accurate estimation of prevalence is essential but challenging due to the variability of blood pressure and the need for multiple occasions for confirmation. This study aimed to estimate the national, regional, and provincial prevalence of childhood hypertension in China in 2020.

Methods: For this systematic review and modelling study, we did a comprehensive literature search of epidemiological studies reporting the prevalence of elevated blood pressure (EBP) or hypertension among Chinese children (aged 18 years or younger) that were published between Jan 1, 1990 and June 20, 2024 in PubMed, Embase, MEDLINE, China National Knowledge Infrastructure, Wanfang Data, and Chinese Science and Technology Journal Database. EBP was defined as blood pressure greater than or equal to the 95th percentile on a single occasion, and childhood hypertension as blood pressure greater than or equal to the 95th percentile consistently across three occasions. First, we estimated the prevalence of childhood EBP using a multi-level mixed-effects meta-regression and the pooled odds ratios (ORs) for factors associated with childhood EBP through random-effects meta-analysis. Second, the ratio of childhood EBP to childhood hypertension was calculated via random-effects meta-analysis, based on which the national and regional prevalence of childhood hypertension was imputed. Finally, we derived the provincial prevalence of childhood hypertension using an associated factor-based model. The review protocol was registered in PROSPERO (CRD42024537570).

Findings: We identified 8872 records, of which 134 articles covering 22 431 861 children were included. In 2020, the overall prevalence of hypertension among Chinese children aged 6-18 years was 3·11% (95% CI 2·35-4·04), equivalent to 6·80 million (5·13-8·83) affected children. The prevalence of childhood hypertension ranged from 2·25% (1·54-2·75) for children aged 6 years to 2·01% (1·36-3·37) for those aged 18 years, peaking at 3·84% (2·97-4·94) for those aged 14 years. The overall prevalence was higher in boys (3·34% [2·53-4·35]) than in girls (2·85% [2·13-3·69]). Associations between four factors (overweight, obesity, salted food intake, and family history of hypertension) and childhood EBP were graded as highly suggestive evidence.

Interpretation: This study reveals substantial regional and provincial variations in the prevalence of childhood hypertension in China. Our findings could inform targeted public health initiatives and optimise resource allocation to address this public health concern.

Funding: This study was supported by the National Natural Science Foundation of China (72104211 and 82273654) and the Chao Kuang Piu High-tech Development Fund (2022RC019).

Translation: For the Chinese translation of the abstract see Supplementary Materials section.