Liu et al. BMC Public Health 2011, 11:931 http://www.biomedcentral.com/1471-2458/11/931 R E S E A R C H A R T I C L E Open Access Adverse trends of cardiovascular risk factors among low risk populations (1983-1994) - a cohort study of workers and farmers in Guangzhou, China Xiaoqing Liu, Jinzhuang Mai, Xuxu Rao, Qiling Zhuo, Chengye Guo, Xiangmin Gao, Yong Wu, Mulan Deng and Shuguang Lin* Abstract Background: The levels and trends of cardiovascular risk factors vary greatly throughout China. We examine 10- year trends of cardiovascular risk factors (1983-1994) and the factors related to these trends among low-risk cohorts of workers and farmers in Guangzhou, China. Methods: This is a cohort study of 3,131 workers and 3,493 farmers aged 25-64 years at baseline with 10 years of follow-up. We performed a longitudinal analysis to account for the aging of the cohorts and the repeated measures of the same individual. Results: At baseline the prevalence of overweight (including obese) ranged from 1.0% to 11.8%, hypertension ranged from 3.8% to 10.5%, and mean serum total cholesterol (TC) ranged from 155.4 mg/dl to 187.2 mg/dl. Although prevalence of smoking declined, blood pressure levels and body mass index (BMI) increased significantly, and lipid profiles changed unfavorably during the 10-year follow-ups. The prevalence of hypertension increased from 5.0 percentage points (female farmers) to 12.3 percentage points (male farmers). Mean TC increased significantly (e.g., +22.8 mg/dl and +17.0 mg/dl in male and female farmers, respectively). In the longitudinal data analyses, increase in BMI was associated with increase in blood pressure levels and TC. Significant adverse trends of risk factors persisted after adjustment for aging, education, BMI, smoking, and alcohol intake. Conclusion: Urgent action is needed to prevent and reverse the unhealthy trends occurring among these low risk Chinese workers and farmers. Background China’s society and economy have been developing rapidly during the past 30 years. Although this growth has resulted in a marked increase in the standard of liv- ing, the health of Chinese population overall is becoming “westernized”, characterized by increasing prevalence of hypertension, diabetes, and cardiovascular disease [1]. Levels and trends of cardiovascular risk factors as well as cardiovascular morbidity and mortality varied greatly throughout China [2-6]. Prevalence of hypertension and * Correspondence: shuguanglin@21cn.com Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Science, 96# Dongchuan Road, Guangzhou 510100, Peoples Republic of China serum total cholesterol (TC) level was much higher in north China than in south China [4,5]. Surveillance data from Sino-MONICA project showed that there was an up to 33-fold difference in the incidence of coronary heart disease among men living in 17 different areas of the country during the late 1980s [2]. From 1987 through 1993, the incidence and mortality of cardiovascular dis- ease increased in some areas, whereas it decreased in others [2]. In Beijing, blood pressure levels in the popula- tions have been reported inconsistently as increased [7], unchanged, or somewhat decreased [6,8] from 1980s to 1990s. TC levels have increased [8] or decreased [9] in some cases as well. In Shanghai, mean blood pressure changed little, whereas TC markedly increased [6]. © 2011 Lui et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited