Comparative analysis of obesity-related cardiometabolic and renal biomarkers in human plasma and serum

The search for biomarkers associated with obesity-related diseases is ongoing, but it is not clear whether plasma and serum can be used interchangeably in this process. Here we used high-throughput screening to analyze 358 proteins and 76 lipids, selected because of their relevance to obesity-associated diseases, in plasma and serum from age- and sex-matched lean and obese humans. Most of the proteins/lipids had similar concentrations in plasma and serum, but a subset showed significant differences. Notably, a key marker of cardiovascular disease PAI-1 showed a difference in concentration between the obese and lean groups only in plasma. Furthermore, some biomarkers showed poor correlations between plasma and serum, including PCSK9, an important regulator of cholesterol homeostasis. Collectively, our results show that the choice of biofluid may impact study outcome when screening for obesity-related biomarkers and we identify several markers where this will be the case.Funding Agencies|Wallenberg Centre for Molecular & Translational Medicine at University of Gothenburg; Knut & Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation; Swedish Research CouncilSwedish Research Council [2016/82]; Swedish Society for Medical Research [S150086]; Ake Wibergs Foundation [M15-0058]; ERCEuropean Research Council (ERC) [804418]; NIH West Coast Metabolomics Center Pilot and Feasibility study through National Institutes of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [U24 DK097154]; NIHUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [U24 DK097154, U2C 030158]; USDAUnited States Department of Agriculture (USDA) [2032-51530-022-00D]; NIH/NHLBIUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Heart Lung & Blood Institute (NHLBI); Swedish Heart Lung FoundationSwedish Heart-Lung Foundation [HL128457, HL107744, 20180199]