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.

The study population was recruited to the Tianjin Brain Study (TBS), a population-based study on stroke incidence and mortality from a township of Ji County in Tianjin, China, since 1985, which is ≈100 km from Beijing. The total population was 15 438 people distributed within 18 administrative villages, and 95% of residents were low-income farmers. The primary source of income was grain production; annual per capita income was <100 USD in 1991 and <1000 USD in 2010. 7 The illiteracy rate in this population was 30% in menBackground and Purpose-Sex differences in secular trends of stroke incidence are rarely reported. We aimed to explore sex differences in incidence and mortality of stroke in rural China from 1992 to 2012. Methods-In 1992, 14 920 residents were recruited to participate in the Tianjin Brain Study, a population-based study on stroke surveillance. Stroke events and all deaths were annually registered. Results-We observed 908 incident strokes (366 in women) from 1992 to 2012. Women were significantly younger than men (64±12 versus 68±11 years) in 1992 to 1998 (P=0.024). The incidence of first-ever stroke per 100 000 person-years for men was 166 in 1992 to 1998, 227 in 1999 to 2005, and 376 in 2006 to 2012; for women, the rates were 86 (1992-1998), 148 (1999-2005), and 264 (2006-2012). From 1992 to 2012, the incidence grew annually by 5.8% in men and 8.0% in women. The male/female incidence ratio declined significantly: 1.9 in 1992 to 1998, 1.5 in 1999 to 2005, and 1.4 in 2006 to 2012. There were no significant sex differences in mortality. The prevalence of obesity and diabetes mellitus, the levels of total cholesterol and triglycerides, and the age of menopause and reproductive years in women concurrently increased in 2011. Conclusions-There was a significant increase in the incidence of first-ever stroke in women annually and a declining trend in the male/female rate ratio in rural China during the past 21 years. These results suggest that stroke will become one of the major diseases affecting women in future decades in China. (Stroke. 2014;45:1626-1631.)