Backgroud: Body mass index (BMI) is commonly used to identify obesity, but it is only a surrogate measure of body fatness. We directly measured the body fatness by bioelectrical impedance anaylsis (BIA) and anaylized the relations of cardiovascular risk factors with body fat percent and body mass index.
Methods: The study subjects were 929 men and 699 women aged 19-69 years, who visited a health promotion center of a general hospital from June to November, 2001. Height, weight, body mass index (BMI) and blood pressure (BP) were checked. Fat mass, fat-free mass, and body fat percent (%BF) were obtained by BIA method. Serum lipids fasting and blood glucose were checked. We assessed the fat mass, fat-free mass and %BF for sex and age decades. Multiple regression analyses were used for cardiovascular risk factors by age, BMI and %BF.
Results: In men, %BF was lowest in their 30s and highest in their 50s, but BMI was not different among the age groups. In women, %BF and BMI were lowest in their 20s and highest in their 60s. After multiple regression analysis in men, %BF was independently related with systolic BP, diastolic BP, total cholesterol, LDL-cholesterol, and fasting glucose, and BMI was related with triglyceride and HDL-cholesterol. In Women, %BF was related with total cholesterol and LDL-cholesterol, and BMI was related with triglyceride, HDL-cholesterol and fasting glucose. In non-obese group, more cardiovascular risk factors were related with %BF than BMI in both men and women.
Conclusion: In non-obese men, more cardiovascular risk factors were related with %BF than BMI.

Keywords: Obesity, Carciovascular rksk factor, Body fat, Body mass index, Bioelectrical impedance