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Introduction: Exposure to airborne particulate matter (PM) is associated with cardiovascular disease. These outcomes are believed to originate from pulmonary oxidative stress and the systemic delivery of oxidised biomolecules (eg, aldehydes) generated in the lungs. Carnosine is an endogenous di-peptide (β-alanine-L-histidine) which promotes physiological homeostasis in part by conjugating to and neutralising toxic aldehydes. We hypothesise that an increase of endogenous carnosine by dietary supplementation would mitigate the adverse cardiovascular outcomes associated with PM exposure in humans., Methods and Analysis: To test this, we designed the Nucleophilic Defense Against PM Toxicity trial. This trial will enroll 240 participants over 2 years and determine if carnosine supplementation mitigates the adverse effects of PM inhalation. The participants will have low levels of endogenous carnosine to facilitate identification of supplementation-specific outcomes. At enrollment, we will measure several indices of inflammation, preclinical cardiovascular disease and physical function. Participants will be randomly allocated to carnosine or placebo groups and instructed to take their oral supplement for 12 weeks with two return clinical visits and repeated assessments during times of peak PM exposure (June-September) in Louisville, Kentucky, USA. Statistical modelling approaches will be used to assess the efficacy of carnosine supplementation in mitigating adverse outcomes., Ethics and Dissemination: This study protocol has been approved by the Institutional Review Board at the University of Louisville. Results from this study will be disseminated at scientific conferences and in peer-reviewed publications. Trial registration: NCT03314987; Pre-results., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Epidemiological studies demonstrate a beneficial effect of physical activity (PA) on various biological health outcomes associated with diabetes; however, these studies have been limited by the use of self-report measures of PA. To provide the most accurate association between PA and health among adults with diabetes, the purpose of this study was to examine the association between accelerometer-assessed PA and numerous biological markers associated with diabetes. Data from the 2003-2006 National Health and Nutrition Examination Survey were used. Adult participants with diabetes were included in the present study and wore an ActiGraph 7164 accelerometer. Light and moderate-to-vigorous PA (MVPA) intensity was determined from accelerometer-derived estimates. Various biological measures, such as triglycerides and C-reactive protein, were measured from a blood sample. Results showed that both light-intensity and MVPA were inversely associated with several biological health outcomes. Additionally, active adults were less likely to have multiple cardiovascular disease risk factors. Findings also differed by age and gender, suggesting that PA interventions may need to consider the influence that age and gender may have on the efficacy of physical activity interventions., (Copyright © 2013 Elsevier Inc. All rights reserved.)