The goal of this study was to examine the association between adiponectin and low-grade albuminuria in nondiabetic persons and whether it differed between obese and nonobese individuals. Urinary albumin excretion (UAE) was assessed by overnight collection in 157 participants. Overall, as anticipated, 24-hour systolic blood pressure and fasting glucose levels were independent determinants of UAE (beta=0.254 and 0.176, respectively, P<.05). In obese persons (body mass index [BMI] >/=25 kg/m(2); n=63), adiponectin value was a significant negative determinant of UAE (beta=-0.256, P<.05) independent of blood pressure and glucose levels, whereas in nonobese participants (n=94) it was not. In an analysis of BMI and the median value of adiponectin (9.9 microg/mL), UAE was found to be significantly higher in obese persons with low adiponectin levels than in obese persons with high adiponectin levels (9.20 vs 5.11 microg/min; P<.05), even after adjustment for age, sex, blood pressure level, and glucose level. There was an inverse association between adiponectin and low-grade albuminuria in obese nondiabetic persons.