Abstract: Objective To investigate the serum levels of leptin,soluble leptin receptor(sLR),and insulin as well as their relationship in benign acanthosis nigricans.Methods Twenty-five cases of benign acanthosis nigricans,20 cases of simple obesity and 20 healthy controls were detected for the concentrations of plasma leptin,insulin and C-peptide with radioimmunoassay,sLR with enzyme-linked immunoabsorbant assay(ELISA)and fasting blood glucose with glucose oxidase method.Results The body weight,body mass index,percentage of body fat(% BF),waist/hip ratio(WHR),serum insulin,C-peptide and leptin were all significantly higher,whereas the insulin sensitivity index and sLR were statistically lower,in patients with benign acanthosis nigricans or simple obesity than those in the normal controls(all P<0.01).No significant difference was found in fasting blood glucose between patients with benign acanthosis nigricans or simple obesity and the normal controls(P>0.05).Conclusion There is hyperinsulinaemia,insulin and leptin resistance in benign acanthosis nigricans,and leptin resistance may play a role in the occurrence of hyperinsulinaemia,insulin resistance and obesity in benign acanthosis nigricans.

Key words: Acanthosis nigricans, Insulin, Leptin