title: Joint effects of age and body mass index on the incidence of hypertension subtypes in the China Health and Nutrition Survey: A cohort study over 22years.
abstract: We seek to investigate the joint effects of age and body mass index (BMI) on the incident hypertension subtypes among Chinese adults during 1989-2011.
  
  
  
  We investigated the Incidence rates (IRs, per 100person-years) of hypertension subtypes, adjusted relative risks (RRs) and population attributable risk percent (PAR%) of BMI for hypertension, and clarified the age-specific effect of BMI on incident hypertension utilizing a dynamic cohort study from the China Health and Nutrition Survey (CHNS) 1989-2011.
  
  
  
  Normotensive participants (n=53,028) at baseline were included, with mean age was 41.7 (95% CI, 41.6-41.7)years old. During a total of 118,694person years (average was 6.38years) of follow-up, a total of 5208 incident cases of hypertension were documented. The IRs of hypertension were 4.4 (95% CI, 4.3-4.5), which increased gradually by age and BMI (Ptrend<0.001). Compared with those with BMI<22kg/m(2), the RR of hypertension was 3.13 (95% CI, 2.84-3.45) in the group with BMI≥28kg/m(2). The PAR% (BMI>22 vs. BMI<22) for hypertension in Chinese population was 32% (95% CI, 29-34%). Similar trends were observed in all age and BMI groups for both isolated systolic hypertension and systolic-diastolic hypertension, which were mainly affected by age. In contrast, the peak IR of isolated diastolic hypertension was observed in participants aged 30-49years with higher BMIs.
  
  
  
  The PAR% (IR of BP≥140/90 or treatment for BMI>22 vs. IR for BMI<22) of elevated body weight for hypertension was 32% in Chinese population.
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Hebei Medical University, 361 East Zhongshan Road, Shijiazhuang 050017, China.
authors.forename: Su-Fen
authors.initials: SF
authors.lastname: Qi
authors.affiliation: National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, 27 Nanwei Road, Xicheng District, Beijing 100050, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.affiliation: National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, 27 Nanwei Road, Xicheng District, Beijing 100050, China.
authors.forename: Hui-Jun
authors.initials: HJ
authors.lastname: Wang
authors.affiliation: Research Center of Electron Microscope, Hebei Medical University, 361 East Zhongshan Road, Shijiazhuang 050017, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yan
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Hebei Medical University, 361 East Zhongshan Road, Shijiazhuang 050017, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Du
authors.affiliation: Department of Pathology, Hebei Medical University, 361 East Zhongshan Road, Shijiazhuang 050017, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Hebei Medical University, 361 East Zhongshan Road, Shijiazhuang 050017, China.
authors.forename: Ying-Jun
authors.initials: YJ
authors.lastname: Mi
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Hebei Medical University, 361 East Zhongshan Road, Shijiazhuang 050017, China.
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Zhao
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Hebei Medical University, 361 East Zhongshan Road, Shijiazhuang 050017, China.
authors.forename: Dian-Wu
authors.initials: DW
authors.lastname: Liu
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Hebei Medical University, 361 East Zhongshan Road, Shijiazhuang 050017, China. Electronic address: tqb1980@hebmu.edu.cn.
authors.forename: Qing-Bao
authors.initials: QB
authors.lastname: Tian
mesh_terms: D000328:Adult; D000375:Aging; D015992:Body Mass Index; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D008297:Male; D009749:Nutrition Surveys; D012307:Risk Factors
keywords: Chinese; Hypertension; Incidence; Population attributable risk; Relative risk