Objective: To assess the relationship between body mass index (BMI), waist circumference (WC) and blood pressure (BP) including hypertension.
Methods: A total of 30 003 participants aged 35 - 59 from different parts of China were surveyed for cardiovascular disease risk factors in two independent cross-sectional studies that were carried out in 1992 - 1994 and in 1998. Data were pooled to analyze the levels of BP and rates of hypertension with different levels of BMI and WC.
Results: The level of BP and rate of hypertension were significantly increasing with rising of WC among the majority of BMI groups (P value for trend < 0.05) and significantly increasing with rising of BMI in all WC groups (P value for trend < 0.05). The age adjusted hypertension rate with BMI < 24.0 kg/m(2) and WC < 85/80 cm (men/women), BMI < 24.0 kg/m(2) and WC >or= 85/80 cm (M/W), BMI 24.0 - 27.9 kg/m(2) and WC < 85/80 cm (M/W), BMI 24.0 - 27.9 kg/m(2) and WC >or= 85/80 cm (M/W), BMI >or= 28 kg/m(2) and WC >or= 85/80 cm (M/W) were 16.5%, 29.8%, 29.6%, 39.2% and 57.5% for men and 14.1%, 20.6%, 24.7%, 30.3% and 43.3% for women, respectively.
Conclusion: Independent influence of BMI or WC on BP was noticed. Keeping BMI and WC at normal level might effectively prevent the occurrence of hypertension.