Research shows risk of stroke in China linked to socioeconomic status

A large-scale Chinese population-based study by researchers in Britain and China has found an increased risk of stroke in older people associated with low socioeconomic status (SES), particularly in women.

The study, published in the Journal of Epidemiology & Community Health, is led by Professor Ruoling Chen, Head of Population Health Research Group at the University of Wolverhampton, in collaboration with scientists and clinicians from University College London, Liverpool School of Tropic Medicine, Wolverhampton NHS Trust in the UK, Guangzhou Medical University, Beijing Tiantan Hospital and three other medical institutions in China.

Stroke is a leading cause of mortality and disability worldwide. Previous studies in high income countries showed that low SES was associated with increased incidence of stroke in the general population although findings were not consistent. Although different measurements of SES showed variations, no study has assessed the impacts of different SES indicators on risk of stroke simultaneously. There are fewer studies undertaken in low- and middle-income countries (LMICs) to assess the impact of SES on incident stroke. China is the largest LMIC and has the highest estimated lifetime risk of stroke worldwide. Along with rapid economic growth over the past decades, China has an increased gap in income between rich and poor, with stroke being the number one killer.

The team of academics and researchers from the University of Wolverhampton examined the data of the cohort study from China. The study included 5,868 participants aged 60 and over in five provinces across China. Research found that older people with low education, having financial problems, and living in rural areas had increased risk of incident stroke.

They also found that the impacts of low levels of education and personal income on stroke risk in women were stronger than in men, while the association of low SES with increased risk of stroke in older men seemed not as significant.

The first author, Weiju Zhou, a PhD candidate in the Faculty of Education, Health and Wellbeing at the University, said: “Contrary to findings of other studies, our data from the male population showed high occupational class and family income associated with increased risk of incident stroke. These could be attributed to epidemiological transition in the early stages in China that men with high occupational class and income are more likely to have adverse lifestyles including smoking and drinking, sedentary behaviour, and psychological stress. These lifestyles are associated with increased risk of stroke.”

Professor Ruoling Chen said: “Compared to other indicators of SES, the impact of the rural-urban disparity on incident stroke has rarely been studied before. In China there was a wide inequality between rural and urban due to disparities in education, income, employment opportunities, social welfare and healthcare services, and older people living in a rural environment have higher depression and cardiovascular disease risk factors than those living in urban areas.

“Our study is the first to report gender differences in the association of SES with incident stroke, addressing that women had higher inequality in incidence of stroke in relation to low SES. The gender-specific strategies and preventive interventions of health promotion targeting people living in rural areas, through reducing socioeconomic deprivation, would be helpful in campaigns to reduce stroke incidence in China.”

Access the full research report: https://jech.bmj.com/content/early/2020/04/20/jech-2019-213515.full?ijkey=zcOifzUsWHn4j1t&keytype=ref

Picture caption from left to right Professor Ruoling Chen (PhD supervisor), Dr Alex Hopkins (PhD supervisor), Dean of the Faculty of Education, Health and Wellbeing and PhD student Weiju Zhou.