Increasing stroke incidence and prevalence of risk factors in a low-income Chinese population

Objective: We investigated secular trends in incidence of first-ever stroke and the prevalence of stroke risk factors within the same population in rural China.

Methods: In 1985, 15,438 residents from a township of Tianjin, China, were recruited to the Tianjin Brain Study, a population-based stroke surveillance study. Stroke events and all deaths were registered annually. Because imaging technology was first available in 1992, we analyzed the incidence of first-ever stroke over 3 study periods—1992–1998, 1999–2005, and 2006–2012—from 1992 to 2012. Risk factor surveys were conducted in 1991 and 2011.

Results: The age-standardized incidence of first-ever stroke per 100,000 person-years increased rapidly from 124.5 in 1992–1998 to 190.0 in 1999–2005 and to 318.2 in 2006–2012; incidence increased annually by 6.5% overall and by 12% among men aged 45–64 years (p < 0.05). From 1992 to 2012, the age at first-ever stroke in men was earlier by 3.3 years overall, but a similar trend was not observed in women. Concurrently, the prevalence of high fasting glucose and alcohol consumption increased significantly in both men and women, especially in men aged <45 years; the prevalence of obesity and high fasting glucose increased by 8.8-fold and 11-fold, respectively, from 1992 to 2012.

Conclusions: The incidence of stroke in rural China increased rapidly, particularly among middle-aged adults, along with a concurrent increase in risk factor prevalence. These findings suggest that without controlling these risk factors, stroke incidence will continue to increase over future decades in China.