Adiponectin, the gene product of the adipose most abundant gene transcript 1, is a novel adipocyte-derived peptide that has been considered to have antiinflammatory and antiatherogenic effects. To characterize the relationship between adiponectin and lipids metabolism, we measured fasting plasma adiponectin concentration by ELISA, serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), and apolipoprotein (apo) levels in 352 nondiabetic women, 16-86 yr old, with a wide range of body weight [body mass index (BMI), 14.8-36.3 kg/m(2)]. Plasma adiponectin concentrations in women with the highest tertile of TG (1.69 mM < or approximately) were decreased, compared with the middle (1.13 < or = approximately < 1.69) or lowest tertile of TG (approximately < 1.13) (5.9 +/- 0.5 vs. 7.5 +/- 0.3, 9.2 +/- 0.2 microg/ml; P < 0.005, 0.001). Plasma adiponectin with the lowest tertile of HDL-C (approximately < 1.16 mM) was decreased, compared with the middle (1.16 < or = approximately < 1.81) or highest tertile of HDL-C (1.81 < or approximately ) (5.7 +/- 0.5 vs. 7.8 +/- 0.2, 10.1 +/- 0.4 microg/ml; both P < 0.001). These relationships had similar tendencies after adjustment for BMI, body fat mass, age, or diastolic blood pressure. Adiponectin was negatively correlated with serum TG (r = -0.33, P < 0.0001), atherogenic index [(total cholesterol - HDL-C)/HDL-C] (r = -0.34, P < 0.0001), apo B (r = -0.45, P < 0.0001), or apo E (r = -0.29, P < 0.05), and positively correlated with serum HDL-C (r = 0.39, P < 0.0001) or apo A-I levels (r = 0.42, P < 0.002). Those negative relationships became stronger after adjusting for BMI or body fat mass. The slightly positive correlation between adiponectin and age, blood urea nitrogen, or creatinine levels was also observed (all P < 0.001). These results indicate that high-TGnemia and low-HDL-Cnemia are associated with low plasma adiponectin concentrations in nondiabetic women. Further efforts must now be targeted to determine whether adiponectin causes these lipid abnormalities and thus whether it is partly responsible for the atherogenic risk seen in the metabolic syndrome.