A novel oxidized low-density lipoprotein marker, serum amyloid A-LDL, is associated with obesity and the metabolic syndrome

Abstract Background The putative association between the novel oxidized low-density lipoprotein markers, serum amyloid A-LDL (SAA-LDL) and α1-antitrypsin-LDL (AT-LDL), and obesity and the metabolic syndrome (MetS) has not been previously studied. In the present report, we investigated the levels of SAA-LDL and AT-LDL in relation to the components of the MetS. We also assessed the effect of weight reduction therapy on serum SAA-LDL and AT-LDL levels among obese subjects. Methods The study population included 421 obese Japanese outpatients (185 men and 236 women, mean age: 51.1 years) enrolled in the multicenter Japan Obesity and Metabolic Syndrome Study (JOMS). The novel oxidized low-density lipoprotein markers, serum SAA-LDL and AT-LDL, were measured in all participants. Results Circulating SAA-LDL levels were independently associated with the presence and the number of components of the MetS. SAA-LDL levels were also significantly and independently correlated with high-sensitivity C-reactive protein. Notably, successful weight reduction resulted in a significant decrease in circulating SAA-LDL concentrations. Levels of AT-LDL were not associated with the MetS. Conclusions We documented, for the first time, that serum SAA-LDL levels correlate positively with the number of components of the MetS and weight reduction. Whether SAA-LDL may be involved in the pathophysiology of MetS and atherosclerosis deserves further investigation.