Liu et al. BMC Public Health 2011, 11:931 http://www.biomedcentral.com/1471-2458/11/931 Page 5 of 9 Table 2 Age-adjusted prevalence of selected risk factors by year, gender and occupation among cohort populations in Guangzhou, China, 1983-1994 Males Females Workers Farmers Workers Farmers Current smoking (%) Year 0 71.3 80.4 4.3 6.7 Year 4 64.3 75.1 3.3 4.3 Year 10 60.5 72.0 0.8 2.1 Average change in 10 years -10.6* -8.3* -3.5* -4.6* Hypertension (%) Year 0 13.9 10.0 15.7 6.0 Year 4 9.0 11.9 11.6 5.9 Year 10 18.8 22.0 20.7 10.7 Average change in 10 years +5.5* +12.3* +5.5* +5.0* Overweight or obesity (%) Year 0 5.8 0.8 14.2 1.4 Year 4 6.2 2.2 16.2 2.1 Year 10 13.4 6.8 18.4 6.0 Average change in 10 years +7.8* +6.1* +4.2* +4.8* Hyperlipidemia (%) Year 0 6.7 1.7 13.0 2.7 Year 4 15.3 5.1 18.8 3.8 Year 10 14.0 8.6 16.1 5.2 Average change in 10 years +6.2* +6.8* +2.3 +2.5* Note: Hypertension was defined as SBP ≥ 140 mmHg and/or DBP ≥ 90 mmHg or on antihypertensive medication. Overweight was defined as body mass index ≥25 kg/m2 and obese was defined as body mass index ≥30 kg/m2. Hyperlipidemia was defined as serum total cholesterol ≥240 mg/dl and/or low density lipoprotein cholesterol ≥160 mg/dl. *P < 0.001 for 10 years linear trend Table 3 Age-adjusted average changes of risk factor levels by gender and occupation among cohort populations in Guangzhou, China, 1983-1994 Male Female Workers Farmers Workers Farmers b SE Systolic blood pressure (mmHg) 4.9** 0.6 Diastolic blood pressure (mmHg) 2.6** 0.4 Body mass index (kg/m2) 1.2** 0.1 Cigarettes per day Total -2.8** 0.4 Current smoker -1.5** 0.4 Alcohol intake (g/per day) Total -4.4** 1.2 Drinker -12.3** 3.0 Total cholesterol (mg/dl) 9.1** 1.3 Low density cholesterol (mg/dl) 6.5** 1.2 High density cholesterol (mg/dl) -0.8 0.6 Triglycerides (mg/dl) 20.6** 3.9 **P < 0.01; *P < 0.05; and aNot estimated because few females smoked b 7.6** 6.2** 1.4** -2.5** -1.2* -9.2** -13.3** 22.8** 11.7** 7.0** 24.4** SE 0.6 0.4 0.1 0.6 0.6 2.6 3.5 1.4 1.3 0.7 4.5 b 4.6** 1.0** 0.6** a a -0.3* -8.6* 3.1* 3.0* 0.8 -5.8 SE 0.6 0.4 0.1 0.1 4.2 1.3 1.2 0.6 3.4 b 4.2** 4.6** 1.4** a a -0.2 -4.3 17.0** 7.7** 9.0** 1.9 SE 0.5 0.3 0.1 0.2 3.0 1.1 1.0 0.5 2.0