The Study Of Heterogeneity Of Risk Factors Including Diet And Behavior Among Three Hypertension Subtypes

Objective:To investigate hypertension epidemiological characteristics of countryside dwellers who were 35 years or older and not treated with antihypertensive drug in Tongshan Couty, China, study the risk factors of their pulse pressure, and study the heterogeneity of risk factors including demographic, socioeconomic, dietary, and behavioral factors among three hypertension subtypes, namely, ISH, IDH and SDH. The content of this study was also useful to provide the scientific and effective evidence for making decision to prevent hypertension subtypes.Methods:The survey employed a stratified multistage probability sampling design. A total of 20,390 subjects were enrolled for physical examination. After obtaining their consent and administering standardized questionnaires, information sought through the questionnaires was available for 20,364 individuals.19,792 individuals (572 individuals who had been treated with antihypertensive drug not included) were analyzed. First, the demographic characteristic of untreated hypertension patients and normotension was analyzed. Theχ2-test was used for comparing the various risk factors associated with hypertension prevalence. Generalized linear models (GLM) were used to study the risk factors of untreated hypertension patients. Logistic regression was used to study the change of dietary and behavior habits after hypertension diagnosis. Second, the pulse pressure of 19,792 individuals was studied by univariate analysis, and regression tree method was used to decide the risk factors of the pulse pressure. At last, the blood pressure was analyzed by cluster analysis, andχ2-test was used to describe the impacts of common risk factors on hypertension subtypes. The classification trees which were build from the ISH, IDH, SDH patients and normotension were used to compare the different risk factors of three hypertension subtypes. Results:The hypertension prevalence in 19,792 individuals was 31.62%. More than 70% untreated hypertension patients were in the first grade of hypertension. Overall,8.37% of all hypertension patients were aware of their hypertension,2.18% was treated, and 0.72% was controlled.1. The main protective factors of hypertension supported by GLM were as following: young age, low weight, low WHR, clean family fuel, clean drinking water, little passive smoking, no excessive drinking, tasteless, adequate bedtime, good sleep quality, adequate frequency of physical exercise and adequate eating sea foods, egg, meat, and fruit. Some people who had hypertension would change some dietary and behavioral habits including reducing their intaking of salt, alcohol and staple food consumption, eating less pork, more beef and mutton, and their life became more tense. Other dietary and behavioral habits were not changed.2. The mean pulse pressure of subjects with untreated hypertension and normotension was 49.88±12.21 mmHg. The proportion of the subjects with pulse pressure≥60 mmHg was 22.17%, and the proportion with pulse pressure>63 mmHg was 12.90%. The regression tree method indicated that the age was the most important risk factor, and the other important risk factors included resident time, total family person, family monthly income, family monthly expenditure on food, house area, type of cooking fuel used at home, pulsation times, education level, the state of marriage, occupation, BMI, the weight of staple foods consumed daily, years of smoking, kind of drinking, the weight of vegetables ingested daily, frequency of consuming seafood, the state of menstruation and the times of partuaition.3. ISH was the predominant untreated subtype (13.68±0.24%), followed by SDH (11.70±0.23%) and then by IDH (6.24±0.17%). The impacts of common risk factors on subjects with hypertension subtypes were different. Different variables were selected by the program of the classification trees for ISH, IDH, and SDH. For ISH, age was the most important determining factor. The other independent variables that split at various levels included the types of vitamins ingested, family history of stroke, total number of cigarettes smoked, the type of tea consumed, menstruation status, waistline measurement, family history of hypertension, type of edible oil consumed, and body weight. For IDH, the number of cigarettes smoked per day was the most important determining factor. The other independent variables that split at various levels included the types of vitamins ingested, total alcohol intake, family history of tumors, frequency of consuming seafood, waistline measurement, type of tea consumed, type of drinking water consumed, and type of cooking fuel used at home. For SDH, the type of vitamins ingested was the most important determining factor. The other independent variables that split at various levels included age, family history of tumors, frequency of consumption of seafood, body weight, BMI, total number of cigarettes smoked, hip circumference, and frequency of alcohol intake during a week.Conelusions:The hypertension epidemiological characteristics of the people in this study was endemic and serious, the mean pulse pressure was also higher than the mean level of China. The local hypertension patients only changed some dietary and behavioral habits after hypertension diagnosis. The people faced the great risk of cardiovascular disease and living intervention including health diet habit should be taken necessarily and immediately. The age was the most important and independent risk factor of pulse pressure. The pulse pressure was the result of exterior and interior risk factors. ISH and IDH had the different exterior risk factors, caming from interior heterogeneity. The main risk factors of ISH were age and socioeconomic factors. The main risk factors of ISH were dietary, behavioral and hereditary factors. The main risk factors of SDH came from the risk factors of ISH and IDH.