Xiaoxing Cui1, Jicheng Gong2,3, Hailong Han3, Linchen He1, Yanbo Teng4, Teresa Tetley5, Rudy Sinharay5, Kian Fan Chung5, Talat Islam6, Frank Gilliland6, Stephanie Grady7,8, Eric Garshick8,9,10, Zhen Li11, Junfeng Jim Zhang1,2,3,4. 1. Nicholas School of the Environment, Duke University, Durham, North Carolina, USA. 2. BIC-ESAT and SKL-ESPC, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China. 3. Duke Global Health Institute, Duke University, Durham, North Carolina, USA. 4. Duke Kunshan University, Kunshan 215316, China. 5. National Heart and Lung Institute, Imperial College London, London, UK. 6. Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA. 7. Research and Development Service, Veterans Affairs Boston Healthcare System, Boston, Massachusetts, USA. 8. Harvard Medical School, Boston, Massachusetts, USA. 9. Pulmonary, Allergy, Sleep, and Critical Care Medicine Section, Medical Service, VA Boston Healthcare System, Boston, Massachusetts, USA. 10. Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA. 11. Department of Pediatrics, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai 201620, China.
Abstract
BACKGROUND: Oxidative stress is involved in thoracic diseases and health responses to air pollution. Malondialdehyde (MDA) is a well-established marker of oxidative stress, but it may be present in unconjugated and conjugated forms. To our knowledge, no studies have conducted a systemic evaluation of both free MDA (unconjugated MDA) and total MDA (the sum of both unconjugated and conjugated MDA) across various types of human biospecimens. METHODS: Free MDA and total MDA were simultaneously measured in a range of human biospecimens, including nasal fluid (N=158), saliva (N=158), exhaled breath condensate (N=40), serum (N=232), and urine (N=429). All samples were analyzed using an HPLC-fluorescence method with high sensitivity and specificity. Due to the right skewed distribution of free MDA and total MDA, we performed natural-log transformation before subsequent statistical analyses. The relationship between the natural log of free and total MDA was evaluated by R2 of simple linear regression. T test was used for comparisons of means between two groups. One-way analysis of variance was used in combination with Tukey's test to compare the natural log of the ratio of free MDA to total MDA across various types of biospecimens. RESULTS: For exhaled breath condensate, serum, urine, nasal fluid and saliva samples, the R2 between free and total MDA were 0.61, 0.22, 0.59, 0.47 and 0.06, respectively; the medians of the free MDA to total MDA ratio were 48.1%, 17.4%, 9.8%, 5.1% and 3.0%, respectively; the free MDA to total MDA ratio in EBC > serum > urine > nasal fluid > saliva (P<0.001 for pairwise comparisons). CONCLUSIONS: For exhaled breath condensate and urine samples, using either free or total MDA can provide information regarding the level of oxidative stress; however, that is not the case for serum, nasal fluid, and saliva given the low correlations between free and total MDA.
BACKGROUND: Oxidative stress is involved in thoracic diseases and health responses to air pollution. Malondialdehyde (MDA) is a well-established marker of oxidative stress, but it may be present in unconjugated and conjugated forms. To our knowledge, no studies have conducted a systemic evaluation of both free MDA (unconjugated MDA) and total MDA (the sum of both unconjugated and conjugated MDA) across various types of human biospecimens. METHODS: Free MDA and total MDA were simultaneously measured in a range of human biospecimens, including nasal fluid (N=158), saliva (N=158), exhaled breath condensate (N=40), serum (N=232), and urine (N=429). All samples were analyzed using an HPLC-fluorescence method with high sensitivity and specificity. Due to the right skewed distribution of free MDA and total MDA, we performed natural-log transformation before subsequent statistical analyses. The relationship between the natural log of free and total MDA was evaluated by R2 of simple linear regression. T test was used for comparisons of means between two groups. One-way analysis of variance was used in combination with Tukey's test to compare the natural log of the ratio of free MDA to total MDA across various types of biospecimens. RESULTS: For exhaled breath condensate, serum, urine, nasal fluid and saliva samples, the R2 between free and total MDA were 0.61, 0.22, 0.59, 0.47 and 0.06, respectively; the medians of the free MDA to total MDA ratio were 48.1%, 17.4%, 9.8%, 5.1% and 3.0%, respectively; the free MDA to total MDA ratio in EBC > serum > urine > nasal fluid > saliva (P<0.001 for pairwise comparisons). CONCLUSIONS: For exhaled breath condensate and urine samples, using either free or total MDA can provide information regarding the level of oxidative stress; however, that is not the case for serum, nasal fluid, and saliva given the low correlations between free and total MDA.
Authors: M L Bartoli; F Novelli; F Costa; L Malagrinò; L Melosini; E Bacci; S Cianchetti; F L Dente; A Di Franco; B Vagaggini; P L Paggiaro Journal: Mediators Inflamm Date: 2011-06-16 Impact factor: 4.711
Authors: Nusaibah Sallehuddin; Abid Nordin; Ruszymah Bt Hj Idrus; Mh Busra Fauzi Journal: Int J Environ Res Public Health Date: 2020-06-11 Impact factor: 3.390