Inflammation increases plasma angiopoietin-like protein 4 in subjects with the metabolic syndrome and type 2 diabetes

background Angiopoietin-like protein 4 (ANGPTL4) inhibits lipoprotein lipase and associates with dyslipidemia. The expression of ANGPTL4 is regulated by free fatty acids (FFA) that activate lipid-sensing peroxisome proliferator-activated receptors (PPARs), but FFA can also activate pattern recognition receptors including Toll-like receptor 4 (TLR4) in macrophages. objective To assess whether systemic low grade inflammation is a determinant for plasma ANGPTL4 levels in patients with the metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM). design We studied 335 male subjects: healthy controls (Controls), subjects with the metabolic syndrome without inflammation (MetS-I) and with low grade inflammation (MetS+I), and T2DM patients. All non-diabetic subjects included in the present study were initially matched for waist circumference. In plasma, ANGPTL4, C-reactive protein (CRP) and metabolic parameters were determined. Underlying mechanisms were examined using human macrophages in vitro . horse-radish peroxidase for 20 min, and tetramethyl benzidine substrate reagent for 6 min. The reaction was stopped by addition of 50 µl of 10% H 2 SO 4 , and the absorbance was measured at 450 nm.