Analysis Of Prevalence, Awareness, Treatment, And Control Of Hypertension In China

Essential hypertension is a clinical syndrome characterized mainly with the elevation of blood pressure. It is a common disease both in developed and developing countries. It is also an important cause and risk factor for various cardiovascular diseases. The prevalence of hypertension in China has some new trends with the economic development and the improvement of lifestyle in recent years, i.e. the cases of the boundary hypertension are increasing, the onset age is younger, and the prevalence of low epidemic regions is becoming higher. It is estimated that the increasing speed of hypertension is increasing with 3.5 million new cases annually in China. Hypertension is a great disease burden for family and community. OBJECTIVEThe objective of this study was to estimate the prevalence and distribution of hypertension and to determine the status of hypertension awareness, treatment, and control in the general adult population in China. This will be helpful for providing scientific evidences for population based intervention for hypertension, so that to reduce the occurrence of stroke and coronary heart disease in the hypertensive patients, and increase the quality of life for the Chinese population. METHODSThe target participants for this study was the national population aged 35 to 74 years old, the multistage sampling strategies were used to select the study participants. Firstly, four provinces were selected in the southern and northern China (Beijing andShanghai represented the northern and southern China). Secondly, one county and a city were selected from each of the four provinces including Beijing and Shanghai. Thirdly, a city community and a village were selected, and at last, the entire individual participant was randomly selected. Three blood pressure measurements were obtained by trained observers by use of a standardized mercury sphygmomanometer after a 5-minute sitting rest. Information on history of hypertension and use of antihypertensive medications was obtained by use of a standard uestionnaire. Hypertension was defined as a mean systolic blood pressure > or =140 mm Hg, diastolic blood pressure > or =90mm Hg, and/or use of antihypertensive medications. Chi-square test was used to compare the prevalence rates; t-test and analysis of variance were used to test the differences of numerical variables. The independent risk factors for influencing awareness, treatment, and control rates were analyzed by using logistic regression analysis. RESULTS1. The prevalence of hypertensionOverall, 27.2% of the Chinese adult population age 35 to 74 years had hypertension. The age-specific prevalence of hypertension was 17.4%, 28.2%, 40.7%, and 47.3% in men and 10.7%, 26.8%, 38.9%, and 50.2% in women age 35 to 44 years, 45 to 54 years, 55 to 64 years, and 65 to 74 years, respectively. For the geographic distribution, it shows that the prevalence was significantly higher in the northern than the southern (33.8% vs. 23.3%), but there was no difference between city and rural (29.0% vs. 28.1%). The prevalence of hypertension for males was higher than females both in city and rural. 2. Overall, 56.8% of men and 63.4% of women had optimal or normal BP (SBP<130 mm Hg and DBP<85 mm Hg), whereas 16.4% of men and 13.5% of women had high normal BP. The prevalence of stage 1, 2, and 3 hypertension was 18.1%, 5.6%, and 3.2% in men and 15.0%, 5.7%, and 2.4% in women, respectively.2. The distribution of the blood pressure levelsThe average SBP and DBP for normotensive participants were 32.4 and 14.0 mm Hg lower than the corresponding values for those with treated hypertension, and 33.0 and 15.8 mm Hg lower than the corresponding values for those with untreatedhypertension. In contrast, the SBP and DBP differences between treated and untreated participants with hypertension were only 0.6 and 1.8 mm Hg, respectively.3. Awareness, treatment, and control of hypertensionOverall, 44.7% of those with hypertension were aware of their diagnosis, only 28.2% were taking medication to lower their blood pressure, and only 8.1% achieved blood pressure control. More women were aware of their hypertension than men (50.8% vs. 39.5%). Treatment and control rates were also more common among women than among men. Among women, awareness was most common in the 45- to 64-year age group, whereas among men, the 65- to 74-year age group was most aware of their hypertension. 23.5% of men reported that they were taking anti-hypertensive medication, and the percentage was much lower for men aged 35 to 44 years (13.7%). The treatment rate for women was 33.8%, only 6.1% of men and 10.5% of women with hypertension achieved blood pressure control, and the percentages were even lower for both men and women aged 35 to 44 years (3.9% and 8.3%, respectively).4. The influencing factors for awareness, treatment, and controlHigher awareness (OR; 95%CI) was noted for persons who were married (1.43; 1.09-1.88) and had their blood pressure measured in 1 year (47.4; 31.7-70.4) or 1 to 5 years (11.4; 7.09-18.2) preceding their study visit; lower awareness was found among men (0.62; 0.52-0.74) and current smokers (0.79; 0.63-0.99). Among those aware of their hypertension, treatment was more common (OR; 95% CI) at higher income (1.24 [0.87-1.75], 1.46 [1.01-2.12] and 1.58 [1.06-2.37] for increasing versus the lowest quartile of income) and for participants who had their blood pressure measured during the preceding year (3.87; 1.89-7.93) and was less common among men (0.76; 0.59-0.98). Controlled hypertension was more common (OR; 95% CI) among persons whose blood pressure had been measured 1 year (4.93; 1.51-16.1) and 1 to 5 years (14.8; 3.63-60.5) prior to their study visit and, among persons aware of their hypertension diagnosis, those who undertook lifestyle modification (1.59; 1.11-2.27). CONCLUSIONSThe results indicate that hypertension is highly prevalent in China. There was a marked north-south gradient in the prevalence of hypertension in China. Thepreviously reported urban-rural difference in the prevalence of hypertension was not noted, perhaps due to a rapid increase in the prevalence of hypertension in rural China. The percentages of those with hypertension who are aware, treated, and controlled are unacceptably low. It is urgent need to develop national strategies to improve prevention, detection, and treatment of hypertension in China.