Hypertension has been recognized as a health concern for developing countries. However, there are no current nationwide surveys on the prevalence of hypertension in China (the latest nationwide survey was ten years ago). The goal of this study was to estimate the pooled prevalence of hypertension in Chinese cities.
We systematically reviewed published epidemiologic studies on the prevalence of hypertension in Chinese cities through meta-analysis. We searched for studies published between January 2002 and June 2012 using PubMed and two Chinese electronic publication libraries. The keywords ‘hypertension’ and ‘prevalence’ were used. Before pooling prevalence of hypertension, all raw prevalence data was age adjusted to the 2010 China standard population. Prevalence estimates were stratified by sex and geographic area.
27 studies were identified with of a total of 195,027 study participants. The overall pooled prevalence of hypertension was 21.5% (19.4%, 23.6%). Subgroup analyses showed the following results north 25.8% (21.6%, 30.0%), south 20.4% (18.6%, 22.2%); male 22.2% (19.3%, 25.1%), female 19.9% (17.6%, 22.1%); large cities 18.9% (15.7%, 22.1%), medium-sized cities 24.6% (19.9%, 29.4%), small cities 20.6% (17.5%, 23.7%); study years in 2002–2006, 21.9% (18.9%, 24.8%), and study year in 2007–2011, 20.6% (17.3%, 23.9%).
Comparing data from several previous national hypertension surveys, the prevalence of hypertension is higher in cities than the Chinese national average. Subgroup studies also found a higher prevalence of hypertension in northern cities and among males. Also, the prevalence of hypertension in medium-sized and small cities is likely to increase faster than in large cities.
Citation: Ma Y-Q, Mei W-H, Yin P, Yang X-H, Rastegar SK, Yan J-D (2013) Prevalence of Hypertension in Chinese Cities: A Meta-Analysis of Published Studies. PLoS ONE 8(3): e58302. doi:10.1371/journal.pone.0058302
Editor: Hamid Reza Baradaran, Tehran University of Medical Sciences, Iran (Republic of islamic)
Received: November 21, 2012; Accepted: February 1, 2013; Published: March 6, 2013
Copyright: © 2013 Ma et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: The authors have no support or funding to report.
Competing interests: The authors have declared that no competing interests exist.
Hypertension is the most common risk factor for cardiovascular diseases (CVD) . Hypertension has been recognized as a global, chronic, non-communicable disease and as a “silent killer” due to its high mortality rates and lack of early symptoms. One-quarter of the world’s adult population is hypertensive and this figure is likely to increase to 29% by 2025 . The absolute prevalence of hypertension in developing countries is 22.9% compared with 37.3% in developed countries . Unfortunately, the prevalence of hypertension is growing rapidly in developing countries which are undergoing epidemiological transitions, economic improvement, urbanization and longer life expectancy . Kearney et al.  estimated that by 2025, the number of individuals with hypertension in developing countries will be approximately 1.17 billion, representing almost three-fourths of the world’s hypertensive population. A cross-sectional study from 2002 estimated that nearly 18% of Chinese people age 15 years and older, corresponding to 177 million people, were hypertensive .
As a result of policy reform many people’s lifestyle in many parts of China has become more westernized. In cities, individuals consume a diet high in salt, calories, saturated fat and low in fruits and vegetables. Several studies have hypothesized that these changes may contribute to a higher prevalence of hypertension in urban populations when compared to rural populations –.
“Prevention first,” is the best and most important strategy for China. This strategy requires a sensible plan of action for prevention and improving current policies against hypertension. However, there are no current nationwide studies on the prevalence of hypertension in Chinese cities; the latest nationwide investigation is now ten years old . Therefore, we performed this meta-analysis to systematically review the findings of all current studies and estimate the overall prevalence of hypertension in Chinese cities.
Materials and Methods
Literature Search Strategy
We searched all published articles for epidemiologic studies on the prevalence of hypertension between January 2002 and June 2012 in three electronic databases: CNKI, WANFANG and PUBMED. These results were supplemented by several useful references cited in the key articles. Articles were identified with search strategy “hypertension” AND (“prevalence” OR “epidemiologic studies”) in all databases. Two authors (YQ Ma and WH Mei) screened the titles and abstracts and reviewed the full-text of the eligible articles. Studies in the areas of Hong Kong, Macao and Taiwan were excluded due to cultural differences from mainland China.
Criteria for Inclusion and Exclusion
We included all epidemiologic studies which reported the prevalence of hypertension among Chinese residents over 15 years of age. Enrollment years of the studies used were between 2002 and 2011. Only studies that used random sampling or census data to find participants were used. All source studies were original research written in English or Chinese and contained the minimum information necessary to calculate pooled analysis of prevalence (number of the subjects and number of hypertension events). Studies were included if they explicitly defined hypertension as an average systolic BP (SBP)≥140 mmHg, an average diastolic BP (BP)≥90 mmHg, or self-reported current treatment for hypertension with an antihypertensive medication as defined by the Seventh Annual Report of the Joint National Committee (JNC 7) .
We excluded studies if the participants were limited to a particular occupation, population, age group, community group or location. We excluded studies whose age-specific prevalence of hypertension was not reported. We also excluded studies that utilized nonrandom sampling or non-JNC 7 standards (e.g. self-reported hypertension without measuring blood pressure).
A standardized data abstraction form was designed to capture and code all relevant study-level information required for analysis. Two investigators selected the studies, extracted the data independently, cross-checked them and resolved disagreements by consensus. For all included studies, we recorded the following information: author, year of publication, year of investigation, city, sampling method, data collection method, diagnostic criteria of hypertension, age of subjects, number of subjects, number of people with hypertension, and age-specific prevalence of hypertension.
To estimate pooled age-standard prevalence of hypertension, all raw prevalence data was age adjusted to the 2010 China standard population . According to the expected heterogeneity across studies, a random-effects model was used to calculate pooled age-standard prevalence and calculate 95% confidence intervals (CIs). Statistical heterogeneity was evaluated with the Cochran chi-square (χ2) and quantified with the I2 statistic (low is <25%, moderate 25–50%, high >50%) . In order to deal with heterogeneity and perform secondary analysis, subgroup analysis was necessary. Subgroups were defined as differences in sex, year range of investigation (every two years), and geographical region differences (south and north). Publication bias was evaluated by testing for funnel plot asymmetry, Begg’s Test and Egger’s test. Significance was set at a P value of less than 0.05. All statistical calculations were made using the Stata® Statistical Software Package, Version 11.0 (StataCorp LP, College Station, Texas, USA) and RevMan 5.1 Software (Cochrane Collaboration, London, UK).
After an initial search identified 8,289 studies, application of inclusion and exclusion criteria, 27 studies were selected –. These 27 studies contained of a total of 195,027 subjects determined to be suitable for meta-analysis (Figure 1; Table 1). Most excluded studies focused on a specific population. Furthermore, many studies from the initial search duplicated existing results. Of the 27 identified studies, nine studies , , , , , , , ,  did not report age-specific data according to sex, but had no effect on overall analysis. In summary, age was limited to 15 year olds and above in 20 studies , –, , , , ; 15–69 in four , –; and 15–74 in three , , . Twenty-two studies –, –, –, ,  were from cities in southern China and five , , , ,  were from cities in northern China. Seven studies , , , , , ,  were from large cities, nine were from medium-sized cities , , , , , , , , , and 13 [17–19, 21–24, 39–33] were from small cities. Nineteen studies enrolled participants between 2002 and 2006 – and eight studies enrolled participants between 2007 and 2011 –.
As shown, our initial searches yielded 8,289 citations: 6,494 from CNKI, 831 from TONGFANG, and 964 from PubMed/MEDLINE. After screening titles and abstracts, 125 studies were considered potentially eligible and retrieved in full text. Of these, 97 studies were subsequently excluded because they did not satisfy the inclusion criteria. Thus, 27 fully eligible studies were identified.
Table 1 and Figure 2 show detailed information from the 27 studies selected. The pooled age-standardized prevalence of hypertension was 21.5% (19.4%, 23.6%). Pooled age-standardized prevalence of all subgroups, according to geographical areas, sex, city size and study years are presented in Table 2. The summarized prevalence of northern and southern China were found to be 25.8% (21.6%, 30.0%) and 20.4% (18.6%, 22.2%) respectively. Male and female subgroups were 22.2% (19.3%, 25.1%) and 19.9% (17.6%, 22.1%) respectively. Prevalence in large cities, medium-sized cities and small cities were 18.9% (15.7%, 22.1%), 24.6% (19.9%, 29.4%) and 20.6% (17.5%, 23.7%), respectively. For the first half and last half of the decade covered in this meta-analysis, pooled age-standardized prevalences were 21.9% (18.9%, 24.8%) and 20.6% (17.3%, 23.9%) respectively. Results showed that the pooled age-standard prevalence in northern cities in China was higher than southern cities in China. The prevalence of hypertension in the male population was higher than in females. In addition, the prevalence in medium-sized cities was the highest of the three city size categories. Small city were second and large cities were the lowest. The prevalence was lower in studies conducted between 2007 and 2011 when compared with studies conducted in the first five years.
Figure 2 shows unadjusted prevalence estimates (boxes) with 95% confidence limits (bars) for each study selected; pooled prevalence estimates are represented as diamonds in this plot.
Table 2 shows information regarding heterogeneity and publication bias. We noted significant heterogeneity within studies and subgroups (P<0.000, I2 = (99.2–99.7)).
In our systematic review and meta-analyses of hypertension prevalence, 27 epidemiological studies from 22 cities were selected. These studies covered nine provinces and municipalities in China. All data was collected between 2002 and 2011. At present, there is a lack of nationwide data regarding hypertension prevalence in Chinese cities. Domestic and international literature searches found only one recent review, which focused on prehypertension in China . Additionally, the latest nationwide investigation of hypertension in China is now ten years old . Therefore, our meta-analysis is relevant to current healthcare needs and is based on a large number of subjects, providing a reliable estimate.
This meta-analysis indicates that >1 in 5 (21.5% (19.4%, 23.6%)) Chinese city residents older than 15 years is hypertensive. Prevalence of hypertension has been on the rise in recent decades, national sampling studies from 1958–1959, 1979–1980, 1991 and 2002 – reported prevalences of 5.1%, 7.7%, 13.7% and 17.6% respectively. Although varying methodologies make comparisons complex, the values from our study exceeded these previous national surveys. Possible explanations for this increase in hypertension prevalence may include economic development, urbanization, aging, lifestyle changes, changing eating habits and deterioration of ecological environments. Furthermore, there has been an increase in overweight and obese individuals. Dyslipidemia, high salt diets, smoking, excessive drinking and sedentary lifestyles all increase risk for hypertension –. It was reported that the percentage of the Chinese population living in urban areas increased from 27% in 1990 to 40% in 2005 . Given this trend, the urban proportion of the population will continue to increase. Effective treatment and prevention measures focusing on the high-risk urban populations will have a profound and favorable impact on public health.
The Factor of the Geographic Areas
An epidemiological study of 14 provinces reported that hypertension prevalence was higher in northern China than Southern China ; our study confirmed this result. The pooled prevalence of hypertension in northern cities is higher than in southern cities, 25.8% and 20.4%, respectively.
The Factor of Sex
Previous studies have found rates of hypertension to be higher in men than in women at younger ages, while the reverse was true in older participants , . Although our study cannot show any information about age groups, it showed that the prevalence of hypertension is higher in men than in women in general, 22.2% and 19.9% respectively. Frank H. Fu and Lena Fung found that female subjects generally have fewer CHD risk factors and thus better health than male subjects . XJ Meng found that urban adults males in China had higher prehypertension, with a prevalence of 47.7% and 33.6% in men and women, respectively .
The Factor of City Sizes
City-size-specific estimates indicate that medium-sized cities have the highest prevalence of hypertension (24.6%), followed by small cities (20.6%), and large cities having the lowest prevalence (18.9%). A cohort study found that hypertension was more prevalence in the more urbanized areas, and inequalities across areas at different stages of urbanization have narrowed .
The Factor of Study Years
The pooled age-standardized prevalence of hypertension is slightly lower among studies performed in 2007–2011 than 2002–2006, 20.6% and 21.9% respectively. Due to the heterogeneity in these studies, a national epidemiology survey should be conducted to confirm if the prevalence of hypertension is truly declining.
While we tried our best to adhere to the guidelines for reporting meta-analysis of observational studies , there were several limitations that merit attention.
Meta-regression was not performed, because our study was only designed to report the pooled prevalence in general and in each subgroup. Within each subgroup the heterogeneity of prevalence was high, as such, we assumed that there were other factors likely influencing heterogeneity, including genetic factors, environment, smoking, physical activity and salt intake –. Unfortunately, due to insufficient data in most studies of hypertension prevalence, it is not possible to deduce the effect of these variations on pooled prevalence.
Although strict inclusion and exclusion criteria were used to identify studies in the literature, both inter- and intra-study measurement errors in the ascertainment of BP, classification of subjects and other indices will have occurred. For example, the number of BP measurements can influence the classification of patients as hypertensive . However, in our selected studies, eleven (40.7%) did not reported the time of day that BP measurements were taken or were taken less than three times.
Because there were great disparities in the distribution of healthcare resources between cities, rural areas, coastal regions and inland regions in China , many low-income cities lacked resources to conduct a survey. Although we restrict sampling methods in inclusion criteria, the investigation bias may still affect the meta-analysis outcomes.
In sum, as our study did not identify all variations present in the pooled prevalence. Therefore, we should be careful in prescribing direct policy recommendations from this meta-analysis alone. However, our findings do reveal an important current healthcare issue which deserves the attention of policy makers.
We appreciate Mrs. Sana Kiani Rastegar for her great help and assistance with the manuscript.
Screened and reviewed the articles: YQM WHM. Searched all published articles: XHY JDY. Copyedited the manuscript: SKR. Conceived and designed the experiments: YQM. Analyzed the data: YQM PY. Wrote the paper: YQM.
- 1. Ezzati M, Lopez AD, Rodgers A, Vander Hoorn S, Murray CJL (2002) Selected major risk factors and global and regional burden of disease. Lancet 360: 1347–1360. doi: 10.1016/s0140-6736(02)11403-6
- 2. Kearney PM, Whelton M, Reynolds K, Muntner P, Whelton PK, et al. (2005) Global burden of hypertension: analysis of worldwide data. Lancet 365: 217–223. doi: 10.1016/s0140-6736(05)70151-3
- 3. Yang G, Kong L, Zhao W, Wan X, Zhai Y, et al. (2008) Emergence of chronic non-communicable diseases in China. Lancet 372: 1697–1705. doi: 10.1016/s0140-6736(08)61366-5
- 4. Department of Disease Control and Prevention, Ministry of Health (2006) Report on chronic diseases in China. Beijing, China: Chinese Centre for Disease Control and Prevention.
- 5. Wang Z, Wu Y, Zhao L, Li Y, Yang J, et al. (2004) Trends in prevalence, awareness, treatment and control of hypertension in the middle-aged population of China, 1992–1998. Hypertens Res 27: 703–709. doi: 10.1291/hypres.27.703
- 6. Yan S, Li J, Li S, Zhang B, Du S, et al. (2012) The expanding burden of cardiometabolic risk in China: the China Health and Nutrition Survey. Obes Rev 13: 810–821. doi: 10.1111/j.1467-789x.2012.01016.x
- 7. Ma WJ, Tang JL, Zhang YH, Xu YJ, Lin JY, et al. (2012) Hypertension prevalence, awareness, treatment, control, and associated factors in adults in southern China. Am J Hypertens 25: 590–596.
- 8. Gu D, Gupta A, Muntner P, Hu S, Duan X, et al. (2005) Prevalence of cardiovascular disease risk factor clustering among the adult population of China: results from the International Collaborative Study of Cardiovascular Disease in Asia (InterAsia). Circulation 112: 658–665. doi: 10.1161/circulationaha.104.515072
- 9. Wu Y, Huxley R, Li L, Anna V, Xie G, et al. (2002) Prevalence, awareness, treatment, and control of hypertension in China: data from the China National Nutrition and Health Survey 2002. Circulation 118: 2679–2686. doi: 10.1161/circulationaha.108.788166
- 10. Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, et al. (2003) Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. National Heart, Lung, and Blood Institute; National High Blood Pressure Education Program Coordinating Committee. National High Blood Pressure Education Program Coordinating Committee. Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension 42: 1206–1252. doi: 10.1161/01.hyp.0000107251.49515.c2
- 11. Population Census Office under the State Council Department of Population and Employment Statistics National Bureau of Statistics. (2012) Tabulation on the 2010 population on the 2010 population census of people’s republic of China. China Statistics Press. Beijing. 52–54.
- 12. J. P. T Higgins, S. G Thompson (2002) Quantifying heterogeneity in a meta-analysis. Statistics in Medicine 21: 1539–1558. doi: 10.1002/sim.1186
- 13. Jiao SF, Wang Y, Pang XH, Yin XJ, Xie J, et al. (2005) Analysis on prevalence and epidemic trend of hypertension in Beijing. Chin J Public Health 21: 1491–1492.
- 14. Wu WQ, Li R, Lu W (2006) Investigation on status of hypertension in urban and rural residents of Shanghai city. Chin J Public Health 22: 858–859.
- 15. Liu XF, Liu DW, Yang XL, Jiang BQ, Zhang HD, et al. (2007) Analysis on prevalence of hypertension and influencing factors related to hypertension in Chongqing. Modern Preventive Medicine 34: 3444–3446.
- 16. Fang SY, Zhu XX, Jin DF, Liu QM, Jiang HR, et al. (2004) Analysis on prevalence of hypertension in Hangzhou in 2003. Prevention and Treatment of Cardio-Cerebral-Vascular Disease 4: 40–42.
- 17. Cui MY, Jin KL, Xia DM, Pang QQ (2004) Analysis on hypertension sampling investigation in Huzhou city. Prevention and Treatment of Cardio-Cerebral-Vascular Disease 4: 42–44.
- 18. Gu WL, Zhou AF, Li XQ, Cao JS, Wang JR (2004) Epidemiological investigation of tendency and influence factors for hypertension in Jiaxing city. Chin J Chronic Diseases 3: 39–41.
- 19. Xu ZX, Wang HP, Wang WF, Zhang LP (2004) Epidemiological survey on hypertension in urban and rural of Jinhua city. Prevention and Treatment of Cardio-Cerebral-Vascular Disease 4: 48–49.
- 20. Zhang LY, Xu ZY, Du WP, Xu KH, Cao JF, et al. (2004) A Survey of 1162 People’s Blood Pressure in Ningbo. Prevention and Treatment of Cardio-Cerebral-Vascular Disease 4: 20–25.
- 21. Jiang PZ, Jiang YM, Hu YG (2004) Epidemiological investigation on hypertension in Quzhou city in 2003. Prevention and Treatment of Cardio-Cerebral-Vascular Disease 4: 50–51.
- 22. Zhang YF, Chen EC, Shan XR (2004) Epidemiological investigation on hypertension in Shaoxin city in 2003. Prevention and Treatment of Cardio-Cerebral-Vascular Disease 4: 52–54.
- 23. Chen LJ, Chen XF, Liang H, Chen Y, Nai J (2006) Investigation on prevalence of hypertension and related risk factors in urban and rural of Taizhou city. Chin J Prevention and Control of Chronic Diseases 14: 437–439.
- 24. Zhang JH, Yuan GY, Ruan LS (2006) Epidemiological survey and risk factor analysis of hypertension in Zhoushan. Chin J Naut Med & Hyoerbar Med 13: 105–107.
- 25. Li SP (2007) Prevalence of hypertension in Qingdao’s residents. Chin J Health Education 23: 593–597.
- 26. Hong Y, Hang LY, Ji XJ, Wang EM, Xiang JL (2007) The Current situation of hypertension prevalent rate and the rates of illness-awareness, medication and blood pressure control in Wenzhou. Chin J Prev Contr Chron Non-commun Dis 15: 356–358.
- 27. Liu WJ, Chen WQ, Luo BF, Pan BY, Chen J, et al. (2007) Analysis on epidemiological characteristics and control status of hypertension in residents aged 15 and above in Guangzhou. Chin J Prev Contr Chron Non-commun Dis 15: 110–112.
- 28. Li L, Liu QM, Fang SY, Chen RH, Shi WY, et al. (2007) Epidemiological survey on prevalence of hypertension in urban and rural of Hangzhou in 2005. Chin Prev Med 8: 234–237.
- 29. Huang XB, Hu R, Le QR, Hou YL, Luo KL, et al. (2009) Epidemiological study of hypertension in Chongqing area of China. Chin J Pubulic Health 25: 25–27.
- 30. Liu ST, Jiang T, Zhang DY, Wang QX, Tang HJ, et al. (2007) Investigation on status of hypertension in urban and rural residents of Mianyang city. Sichuan Medical Journal 28: 1311–1313.
- 31. Tang XR, Wu LP (2008) Investigation on prevalence and TCM syndrome differentiation of hypertension in Jiangmen city, Guangdong province. J New Chin Med 40: 39–41.
- 32. Chen B, Li DY, Liang XD, Li YR (2011) Prevalence of hypertension and its influence factors among inhabitants aged 15–69 years in Zhuhai city. Chin J Public Health 27: 619–621.
- 33. Li CL, Chen AF, Pu YY, Yang QC, Jiang RL, et al. (2008) An epidemiological study on essential hypertension in Yibin city. Med J West China 20: 117–120.
- 34. Zhou Q, Pan BY, Lin GZ, Wu XJ, Liang BH, et al. (2010) Prevalence, awareness, treatment and control of hypertension in 15–69 years old residents in Guangzhou. Chin J Prev Contr Chron Dis 18: 587–590.
- 35. Li XJ, Xu JY, Yao HH, Lu W (2010) Epidemiological status of hypertension in residents aged between 15 and 69 in Shanghai. Chin J Prev Contr Chron Dis 18: 233–235.
- 36. Yan YY (2010) Study on the hypertension prevalence and control strategies in Shijiazhuang. Modern Preventive Medicine 37: 2906–2910.
- 37. Peng ZR, Wang BG, Zhou HB, Ma YQ, Lei L, et al. (2011) Prevalence of metabolic syndrome among permanent residents aged 15 years and above in Shenzhen city. China Tropical Med 11: 852–854.
- 38. Wang HX, Bo FB, Gao XY, Yang L, Yang JM, et al. (2010) Study on the prevalence status and influencing factors of hypertension in Huhhot urban and rural residents. Inner Mongolia Med 42: 1234–1237.
- 39. Cheng MN, Xu JY, Yao HH, Yan QH, Li XJ, et al. (2012) Prevalence of Hypertension in Residents Aged over 15 Years in Shanghai, 2010. J Environ Occup Med 29: 339–342.
- 40. Guo XF, Zou LL, Zhang XG, Li J, Zheng LQ, et al. (2011) Prehypertension a meta-analysis of the epidemiology, risk factors, and predictors of progression. Tex Heart Inst J 38: 643–652.
- 41. Yusuf S, Reddy S, Ounpu S, Anand S (2001) Global burden of cardiovascular disease: part I: general considerations, the epidemiologic transition, risk factors, and impact of urbanization. Circulation 104: 2746–2753. doi: 10.1161/hc4601.099487
- 42. The national hypertension sampling investigation group (1995) China’s population hypertension prevalence rate and the change trend. J Hypertens 3: 7–13.
- 43. Li LM, Rao KQ, Kong LZ, Yao CH, Xiang HD, et al. (2005) A description on the Chinese national nutrition and health survey in 2002. Chin J Epidemiol 26: 478–484.
- 44. Van de Poel E, O'Donnell O, Van Doorslaer E (2009) Urbanization and the spread of diseases of affluence in China. Econ Hum Biol 7: 200–216. 45. Diez Roux AV (2003) Residential Environments and Cardiovascular Risk. J Urban Health 80: 569–589.
- 45. Bell AC, Ge K, Popkin BM (2002) The road to obesity or the path to prevention: motorized transportation and obesity in China. Obes Res 10: 277–283. doi: 10.1038/oby.2002.38
- 46. Zalesin KC, Franklin BA, Miller WM, Peterson ED, McCullough PA (2011) Impact of obesity on cardiovascular disease. Med Clin North Am 95: 919–937. doi: 10.1016/j.mcna.2011.06.005
- 47. Guo ZR, Hu XS, Wu M, Zhou MH, Zhou ZY (2009) A prospective study on the association between dyslipidemia and hypertension. Chin J Epidemiol 30: 554–558.
- 48. Popkin BM (2003) Dynamics of the nutrition transition in the developing world. Fourn Nutr 56: 262–264.
- 49. Conlin PR (2007) Eat your fruits and vegetables but hold the salt. Circulation 116: 1530–1531. doi: 10.1161/circulationaha.107.729574
- 50. Zhang J, Guo YM, Zhang YY, Wu Y, Wang LJ, et al. (2006) A meta analysis on the association between smoking and hypertension according to Chinese residents. Chin J Public Health 22: 1344–1345.
- 51. Malinski MK, Sesso HD, Lopez-Jimenez F, Buring JE, Gaziano JM (2004) Alcohol consumption and cardiovascular disease mortality in hypertensive men. Arch Intern Med 164: 623–628. doi: 10.1001/archinte.164.6.623
- 52. Beunza JJ, Martínez-González MA, Ebrahim S, Bes-Rastrollo M, Núñez J, et al. (2007) Sedentary behaviors and the risk of incident hypertension: the SUN Cohort. Am J Hypertens 20: 1156–1162.
- 53. United Nations (UN) (2007) Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat, World Population Prospects: The 2007 Revision. Available at: http://esa.un.org/unup.
- 54. Zhao XL, Chen J, Cui YL, Wu F, Hu DY (2006) Current status of primary hypertension in China: an epidemiological study of 14 provinces, 1 autonomous regions and 1 municipality. Natl Med J China 86: 1148–1152.
- 55. Wu X, Duan X, Gu D, Hao J, Tao S, et al. (1995) Prevalence of hypertension and its trends in Chinese populations. International Journal of Cardiology 52: 39–44. doi: 10.1016/0167-5273(95)02443-z
- 56. Hou X (2008) Urban-rural disparity of overweight, hypertension, undiagnosed hypertension and untreated hypertension in China. Asia-Pacific Journal of Public Health 20: 159–169. doi: 10.1177/1010539507312306
- 57. Frank HF, Lena F (2004) The cardiovascular health of residents in selected metropolitan cities in China. Prev Med 38: 458–467. doi: 10.1016/j.ypmed.2003.11.022
- 58. Meng XJ, Dong GH, Wang D, Liu MM, Liu YQ, et al. (2012) Epidemiology of prehypertension and associated risk factors in urban adults from 33 communities in China-the CHPSNE study. Circ J 76: 900–906. doi: 10.1253/circj.cj-11-1118
- 59. Ellen VP, Owen OD, Eddy VD (2009) Urbanization and the spread of diseases of affluence in China. Econ Hum Biol 7: 200–216. doi: 10.1016/j.ehb.2009.05.004
- 60. Stroup DF, Berlin JA, Morton SC, Olkin I, Williamson GD, et al. (2000) Meta-analysis of observational studies in epidemiology: a proposal for reporting. Meta-analysis Of Observational Studies in Epidemiology (MOOSE) group. JAMA 283: 2008–2012. doi: 10.1001/jama.283.15.2008
- 61. Colhoun HM, Hemingway H, Poulter NR (1998) Socio-economic status and blood pressure: an overview analysis. J Hum Hypertens 12: 91–110. doi: 10.1038/sj.jhh.1000558
- 62. Kunes J, Zicha J (2006) Developmental windows and environment as important factors in the expression of genetic information: a cardiovascular physiologist’s view. Clin Sci (Lond) 111: 295–305. doi: 10.1042/cs20050271
- 63. Marteau JB, Zaiou M, Siest G, Visvikis-Siest S (2005) Genetic determinants of blood pressure regulation. J Hypertens 23: 2127–2143. doi: 10.1097/01.hjh.0000186024.12364.2e
- 64. Virdis A, Giannarelli C, Neves MF, Taddei S, Ghiadoni L (2010) Cigarette smoking and hypertension. Curr Pharm Des 16: 2518–2525. doi: 10.2174/138161210792062920
- 65. Schmidt-Trucksäss A, Weisser B (2011) Vascular aging, arterial hypertension and physical activity. Dtsch Med Wochenschr 136: 2367–2371. doi: 10.1055/s-0031-1292053
- 66. Frisoli TM, Schmieder RE, Grodzicki T, Messerli FH (2012) Salt and hypertension: is salt dietary reduction worth the effort? Am J Med 125: 433–439. doi: 10.1016/j.amjmed.2011.10.023
- 67. Birkett NJ (1997) The effect of alternative criteria for hypertension on estimates of prevalence and control. J Hypertens 15: 237–244. doi: 10.1097/00004872-199715030-00004
- 68. Lee L (2004) The current state of public health in China. Annu Rev Public Health 25: 327–339. doi: 10.1146/annurev.publhealth.25.101802.123116