Comparison of risk factors associated with hypertension subtypes by classification tree method in Tongshan County of Jiangsu Province, China.
BACKGROUND
There are only a very limited number of studies relating to risk factors for hypertension in rural populations in China. There are even fewer studies comparing various hypertension subtypes.


METHODS
A cross-sectional investigation was carried out in a representative sample of 20,390 subjects drawn from among 1,180,000 adult residents of Tongshan County of Jiangsu Province, China. The impact of risk factors including demographic, socioeconomic, dietary, and behavioral, on three hypertension subtypes, namely, isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and systolic-diastolic hypertension (SDH), was analyzed by applying statistical tests and a classification tree.


RESULTS
ISH was the predominant untreated hypertension subtype (13.68 +/- 0.24%) in the adults of Tongshan County, followed by SDH (11.70 +/- 0.23%) and IDH (6.24 +/- 0.17%). Age, number of cigarettes smoked daily, and the types of vitamins taken varied among the ISH, IDH, and SDH classification trees. Low socioeconomic status was associated with an increased risk for ISH and SDH. Light alcohol intake was associated with higher risk for ISH, but with lower risks for IDH and SDH. Light cigarette smoking was associated with higher ISH risk but lower SDH risk. The intake of appropriate amounts of fish, shrimp, or meat lowered the risks for ISH and IDH. The intake of appropriate amounts of seafood, eggs, milk, or fruit lowered the risks for all hypertension subtypes. Interestingly, an excessive preference for sweet or salty foods was associated with a higher risk for all the subtypes.


CONCLUSIONS
In Tongshan County, there was a considerable prevalence of hypertension of various subtypes, each associated with distinctive and complex risk factors. This suggests that there is a need for testing more diverse prevention measures, tailored to specific subtypes.
Department of Nutrition and Food Hygiene, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
Hailei
H
Wu
Jiqu
J
Xu
Lang
L
Zhuo
Lingcai
L
Han
Wei
W
Bao
Shuang
S
Rong
Ping
P
Yao
Chenjiang
C
Ying
Liegang
L
Liu
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking; D000465:Algorithms; D002681:China / Q000453:epidemiology; D003971:Diastole; D005260:Female; D006801:Humans; D006973:Hypertension / Q000145:classification / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012959:Socioeconomic Factors; D013599:Systole