Waist circumference (WC) has been postulated to have stronger associations with biomarkers of coronary heart disease (CHD) than BMI. In this study, we measured the level of activity by determining steps walked per day and select biomarkers for CHD risk in 80 overweight or obese (BMI = 25-37 kg/m(2)) premenopausal women to evaluate whether these biomarkers are associated with WC or BMI. The plasma biomarkers measured, using samples from women who had fasted for 12 h, were lipids, apolipoproteins (apo), LDL peak diameter, LDL susceptibility to oxidation, glucose, leptin, and insulin. We identified subjects with the metabolic syndrome (11%) and insulin resistance (30%) to further distinguish subjects at increased risk for CHD. Both BMI and WC were positively correlated with insulin (r = 0.376 and 0.384, respectively, P < 0.05) and leptin (r = 0.614 and 0.512, respectively, P < 0.01) and negatively correlated with the number of steps taken per day (r = -0.245 and -0.354, respectively, P < 0.05). In addition, WC had positive correlations with diastolic blood pressure (r = 0.250, P < 0.05), plasma triglycerides (TG) (r = 0.270, P < 0.05), and apo C-III (r = 0.240, P < 0.05). Women with BMI > or = 30 kg/m(2) or WC > 88 cm had significantly higher leptin concentrations than women having a BMI < 30 kg/m(2) or a WC < or = 88 cm; women with WC > 88 cm also had higher diastolic pressure (P < 0.05), and higher plasma TG (P < 0.05) and apo C-III (P < 0.05) concentrations than those with WC < or = 88. In addition, subjects with the higher WC walked an average of 1000 fewer steps per day (P < 0.01). These results suggest that WC is a stronger predictor of CHD risk than BMI and is more closely associated with the level of exercise in premenopausal women.