Trends in incidence of hypertension in Chinese adults, 1991-2009: The China Health and Nutrition Survey

Background/objectives: Previous studies have shown an upward trend in the prevalence of hypertension, but data on trend of incidence of hypertension are lacking. We seek to investigate the trends in incidence of hypertension and control of incident hypertension among Chinese adults during 1991-1997 and 2004-2009. Methods: Within the China Health and Nutrition Survey (1991-2009), we identified five cohorts of adults (age >= 18 years) who were free of hypertension at baseline of each cohort: cohorts 1991-1997 (n = 4107), 1993-2000 (n = 4068), 1997-2004 (n = 4141), 2000-2006 (n = 4695), and 2004-2009 (n = 4523). Data on demographics, smoking, alcohol intake, physical activity, body mass index (BMI), and blood pressure were collected through interviews and clinical examination. Hypertension was defined as blood pressure >= 140/90 mmHg or currently using antihypertensive drugs. Multiple generalized estimation equations and Coxregression models were used to test the trends in blood pressure, incidence of hypertension, use of antihypertensive drugs, and control status of incident hypertension. Results: After controlling for potential confounders, incidence of hypertension (per 100 person-years) significantly increased from 2.9 in 1991-1997 to 5.3 in 2004-2009 (p(trend) = 0.024); the linear trend was statistically or marginally significant in the age group of 18-39 years, in women, in rural residents, and in adults with normal BMI. The overall rates of antihypertensive treatment and control of incident hypertension increased significantly from 5.7% and 1.7% in 1991-1997 to 19.9% and 7.6% in 2004-2009, respectively (p(trend) < 0.001). Conclusions: The incidence of hypertension has increased in Chinese adults since early 1990s. The treatment and control status of incident hypertension, while improved, remain very poor. (C) 2014 Elsevier Ireland Ltd. All rights reserved.