OBJECTIVEThis study observed the association between body mass index (BMI), waist circumference (WC) and blood pressure level in rural residents from west Liaoning province.

METHODSThis epidemiological study using stratified cluster random sampling was conducted from 2004 to 2006 in Fuxin County, Liaoning Province, 43,692 rural residents (21,680 males) aged 35-74 years old [(49. 8 +/-10.2) years] were surveyed. Database was established with the help of Epidata 3.1 software.

RESULTSIn total 43,692 persons were surveyed, including 21,680 male (49.6%) and 22,012 female (50.4%). The average BMI and WC was (23.31 +/- 3.08) kg/m2 and (80.87 +/- 9.0) cm, respectively. No matter male or female, SBP started from 20 kg/m2, increased with the increase of BMI; DBP increased gradually with the increase of BMI; the prevalence of hypertension were significant differences among different BMI groups (P < 0.001). Multiple logistic regression show that in male, using the group with BMI, <18 kg/m2 as control, 28-30 kg/m2 group OR and 95% CI was 6.285 (4.612-8.566); in female, when BMI >22 kg/ m2 OR increased with the increasing of BMI. In male and female, both SBP and DBP, also the prevalence rate of hypertension increased gradually with the increase of WC (P < 0.001). No matter in male or female, when BMI <24 kg/m2, and WC male <85 cm, female WC <80 cm, the average blood pressure levels and prevalence of hypertension are the lowest; after adjusting for age and other risk factors, the prevalence rate of overweight and obesity for male with hypertension OR are 1.704 (1.592-1.825) and 3.710 (3.148 -4.371) , respectively, for female is 1.527 (1.428-1.632) and 3.014 (2.668-3.405), respectively. When the WC is higher than the standard, male and female hypertension risk OR and 95% CI are 1.231 (1.153-1.314) and 1.353 (1.269-1.442), respectively.

CONCLUSIONBoth BMI and WC are risk factors of hypertension.