Adiponectin may be a biomarker of early atherosclerosis of smokers and decreased by nicotine through KATP channel in adipocytes

•Adiponectin levels were negatively correlated to intima-media thickness and positively correlated to C1 as well as C2 in smokers with early atherosclerosis.•Nicotine significantly decreased adiponectin secretion in adipocytes in vitro.•Adiponectin secretion was rescued by inhibitor of the ATP-dependent potassium (KATP) channel.•Nicotine might decrease adiponectin secretion through KATP channel.