Risk of progression to hypertension across baseline blood pressure in nonhypertensive participants among rural Chinese adults: a prospective study

Abstract

To assess the risk of progression to hypertension across baseline blood pressure (BP) level among rural Chinese adults. A population-based sample of 24 052 rural Chinese adults aged at least 35 years and free from hypertension at baseline were followed up from 2004-2006 to 2008. Incident hypertension was defined as SBP of at least 140 mmHg, DBP of at least 90 mmHg, current use of antihypertensive medication, or all. During a median follow-up of 28 months, 26.5% participants developed clinical hypertension, most of which were untreated and uncontrolled. The cumulative incidence of hypertension in participants with optimal, normal, and high-normal BP was 21.2, 25.2, and 32.4%, respectively. The higher incidence of hypertension (per 100 person-years) was obviously observed in higher BP category at baseline among both older and younger groups (both P for trend <0.05). Compared with optimal BP, the adjusted hazard ratios of participants with normal and high-normal BP for incident hypertension were 1.16 (95% confidence interval 1.08-1.24) and 1.28 (95% confidence interval 1.20-1.36), respectively. In addition, older age, men, Mongolian ethnicity, alcohol drinking, family history of hypertension, BMI, and change in BMI during follow-up were also independently associated with incident hypertension. There was a stepwise increase in risk of progression to hypertension across baseline BP level. This information could help us define a population at high risk of progression to hypertension, to underscore the importance of frequent BP monitoring, and early interventions in rural Chinese adults.