Geographic Variations of Stroke Incidence in Chinese Communities: An 18-Year Prospective Cohort Study from 1997 to 2015

Abstract

Background and Purpose As a leading cause of disability and death in China, stroke as well as its epidemiologic features have gained increasing attention. Prior studies, however, have overgeneralized the north-to-south gradient in China. Whether the differences exist across urban and rural areas remains unexplored. This study therefore aims to investigate the north-to-south gradient in stroke incidence across urban and rural China.Methods The present prospective cohort study analyzed data from the China Health and Nutrition Survey 1997 to 2015. By including 16,917 individuals from diverse social contexts, we calculated the age-standardized incidence of stroke across regions and the age-adjusted risk ratio (aRR). Cox proportional hazards models with time-varying covariates were employed to analyze variations in incident stroke.Results During the follow-up, age-standardized incidence of stroke ranged from 4.17 per 1,000 person-years (95% confidence interval [CI], 3.38 to 4.96) in the north region to 1.95 (95% CI, 1.60 to 2.30) in the south region (aRR, 2.04; 95% CI, 1.58 to 2.64; <i>P</i><0.001). The north-to-south gradient of stroke incidence was observed only in rural areas, but not in urban areas. Hierarchical modelling analyses further indicated that the regional differences could be mostly explained by the disparities in the prevalence of hypertension.Conclusions The present study extends the current evidence on the north-to-south gradient by demonstrating that the difference varied across urban and rural China. Our findings highlight the importance of hypertension management as the measure for alleviating regional differences in stroke incidence.

Long-term trends and regional variations of hypertension incidence in China: a prospective cohort study from the China Health and Nutrition Survey, 1991–2015

“…Up-to-date information among developing countries could greatly contribute to depict global epidaemiological transitions. Moreover, regional disparities are a major health concern in China as a result of inequitable socioeconomic development and healthcare resource distribution, [16][17][18] while the existing research provides insufficient information regarding the regional disparities in the hypertension incidence. [19][20][21] Hence, this study aims to explore the long-term trends of hypertension incidence among Chinese from diverse social and geographic contexts.…”

Relationship between MTHFR C677T, homocysteine, and ischemic stroke in a large sample of the Han Chinese population

“…Indeed, existing epidemiological evidence suggests that the 40% of geographic variation in stroke incidence and mortality in China could be attributed mainly to differences in the prevalence of hypertension. [26] In our study population, the prevalence of hypertension reached 71.71%. To determine why the incidence of stroke was so high in Heilongjiang Province, we took into account traditional cerebrovascular disease risk factors and genetic factors.…”

“…Indeed, existing epidemiological evidence suggests that the 40% of geographic variation in stroke incidence and mortality in China could be attributed mainly to differences in the prevalence of hypertension. [ 26 ]…”

Prevalence of stroke in China, 2013–2019: A population-based study

“…An 18-year prospective cohort study from 1997 to 2015 provided an extension of the current evidence on the north-to-south gradient by demonstrating that the differences varied across urban and rural China. 39 The existing evidence suggests that adherence to healthy diets (Mediterranean, DASH, or plant-based “prudent”) was associated with reduced risk of stroke. 40 The geographical environments, food cultures, and dietary habits differ substantially between the southern and northern regions of China.…”