Elderly individuals with high IL‐6 levels have proinflammatory HDL (832.16)

Abstract

Introduction: High density lipoprotein removes the oxidatively modified lipids and other toxic molecules from peripheral cells for elimination and thus it is anti inflammatory and protective. Under chronic acute phase pressure, unsaturated fatty acids and phospholipids in HDL undergo oxidative modification and that results in HDL losing its anti inflammatory and protective capacity. Objective: we sought to determine if HDL from individuals with inflammatory background can retain its protective ability. Methods: We recruited a group of elderly, visiting the UCLA clinics (n=40), who had normal (Group 1) or higher than normal plasma IL‐6 levels (Group 2). We followed the UCLA Medical Center IRB rules and instructions and analyzed their plasma sample for HDL anti inflammatory capacity. This was done using monocyte chemotactic activity toward human artery wall cells in co culture. Results: While the plasma HDL cholesterol levels of the two groups was similar (59.2+ 7.6 and 61+6.9 mg per dL respectively) with no significant difference, the HDL protective capacity of the group with high serum IL‐6 level was significantly lower than the group 1 who did not have high circulating IL‐6 levels (‐ 35% vs + 67% respectively, p <0.01). Conclusion: The data obtained indicates that in the elderly with high plasma IL‐6 levels the inflammatory pressure results in the loss of the protective capacity of HDL and this in turn moves the organism toward a vicious cycle. HDL protects lipids and other substances form oxidative modification. Los of HDL protective capacity increases the modification of lipids and other macromolecules in LDL, in cell membrane and basically throughout the organism with the pursuing undesirable structural and functional consequences.Grant Funding Source: NIH