Malondialdehyde in Dried Blood Spots: A Biomarker of Systemic Lipid Peroxidation Linked to Cardiopulmonary Effects

Abstract

Background: Few systemic oxidative biomarkers have been validated for use in resource-limited settings (e.g., rural Africa), where blood collection facilities are lacking. This study aims to evaluate the potential of malondialdehyde (MDA) in dried blood spots (DBS) as a convenient biomarker of cardiopulmonary effects. \n \nMethods: We conducted a cross-validation comparison of matched capillary DBS, plasma, and whole venous blood collected from nine healthy volunteers for the measurement of total MDA (free + conjugated) and C-reactive protein (CRP), a well-established biomarker of systemic inflammation. A field study was then conducted in a population of 441 rural Senegalese women facing routine exposure to severe household air pollution, to examine longitudinal associations of MDA and CRP levels with cardiopulmonary health outcomes and risk factors. \n \nFindings: In the cross-validation study, CRP levels were strongly correlated across DBS, plasma, and whole blood samples. MDA levels were similarly correlated across DBS and whole blood, and were 1~2 orders of magnitude lower in plasma, suggesting that DBS MDA may reflect total oxidation levels in intracellular and extracellular compartments. In the field study, we observed significantly higher MDA levels in women with a history of cardiovascular disease or secondhand smoke exposure. An interquartile range increase in MDA concentration was associated with 0·99% (95% CI: 0·02 – 1·96%) and 22% (95% CI: -2 – 51%) increases in systolic blood pressure and self-reported incidence of chest tightness, respectively. CRP levels were not similarly associated with these outcomes or risk factors. \n \nInterpretation: Results support the use of convenient DBS measures of MDA as a biomarker for cardiopulmonary health risk. \n \nFunding: International Initiative for Impact Evaluation, German Corporation for International Cooperation GmbH, German Federal Ministry of Education and Research, and Duke University’s Energy Initiative. \n \nDeclaration of Interest: None to declare. \n \nEthical Approval: This study consisted of cross-validation and field-vacomponents, both of which were approved by the institutional review board of Duke University.