['Human resistin has been stated to influence preadipocyte cell numbers and to stimulate adipocyte triglyceride lipolysis in vivo and in vitro. However, its role in human obesity remains unclear.', 'Cross-sectional study for comparisons of lean and obese subjects, and subsequent longitudinal 4-month weight loss intervention study in obese subjects.', 'Healthy subjects, lean (n=20, BMI<25) and overweight (n=43, BMI>or=25).', 'Serum resistin, body weight, body fat, waist-to-hip ratio, as well as markers of insulin resistance and lipid metabolism at baseline and after 4 months of intervention.', 'Serum resistin was positively correlated to HOMA-IR (partial r=0.288; P=0.055), serum fructosamines (partial r=0.280; P=0.062), serum NEFA (partial r=0.276; P=0.066) and negatively to age (partial r=-0.349; P=0.019) and serum apolipoprotein A-1 (partial r=-0.363; P=0.014). During the intervention, serum resistin increased significantly (P<0.001). The increase was inversely related to changes in waist-to-hip ratio (P=0.025) and positively to serum apolipoprotein B (P=0.011). In males only, the increase in resistin during weight loss was predicted by total serum cholesterol at baseline (r=0.703, P=0.007). No relation was observed between changes in resistin and changes in HOMA-IR.'] Is increase in serum resistin during weight loss in overweight subjects related to lipid metabolism?