[Study of body mass index and waist circumference in association with blood pressure in adult Guangzhou residents].

Objective: To assess the significance of body mass index (BMI) and waist circumference (WC) measurement in hypertension prediction and diagnosis and formulate the recommended values for these two indexes, aiming to provide scientific basis for determining the indicators and their cut-off points for obesity diagnosis in Chinese subjects.
Methods: A total of 1 265 residents over 20 years old were randomly selected from Yuexiu District of Guangzhou City in our multiphase study. Questionnaire-based survey was conducted in conjunction of the measurement of the height, body weight, WC and blood pressure, the results subjected to multivariate linear regression and logistic regression.
Results: The distribution of BMI varied significantly with gender and age with the subjects. The mean systolic and diastolic blood pressures both gradually increased with BMI, showing obvious linear relationship between BMI and blood pressure. After such factors as age, gender and education background etc were controlled, logistic regression analysis revealed that the risk for hypertension increased with BMI elevation. WC was related to the blood pressure in similar manner as BMI.
Conclusions: We suggest that BMI be used as the indexes for overweight and obesity, the diagnoses of which are established in cases with BMI >or=23 and BMI >or=29 respectively. As the diagnostic index for abdominal obesity, the cut-off point of WC >or=80 cm should be instituted.