6Burr VL,Whehon P, Roceella E J, et al. Prevalence of hypertension in the US adult population. Results from the Third Nation Health and Nutrition Examination Survey ,1988 - 1991 [ J]. Hypertens, 1995,25 (3) :305 -313.
7Kshlrsagar AV, Carpenter M, Bang H, et al. Blood pressure usually considered normal is associated with an elevated risk cardiovascular disease. The aterosclerosis risk in communities (ARIC)study[ J]. Am J Med,2006,119(2) :133 - 141.
8Kearney PM, Whelton M, Reynolds K, et al. World.wide prevalence of hypertension : a systematic review [ J ]. J Hypertens ,2004,22 ( 1 ) : 11 -19.
