Shyam Biswal, Ph.D., and Sanjay Rajagopalan, M.D.
Johns Hopkins University
U01ES026721, R01ES015146, R01ES019616
Air pollution may play a role in the development of cardiometabolic diseases like diabetes, with effects comparable to eating a high-fat diet, say NIEHS grantees. Importantly, effects were reversed when air pollution exposure stopped.
Using male mice, the researchers compared three groups: a control group that received clean filtered air; a group exposed to concentrated PM2.5 air pollution; and a group that received clean filtered air but were fed a high-fat diet. After 14 weeks, they measured cardiometabolic disease risk factors, such as insulin resistance and glucose levels. They also assessed epigenetic changes, or chemical tags that attach to DNA and affect gene expression.
Being exposed to air pollution was comparable to eating a high-fat diet. Mice in both the air pollution and high-fat diet groups had impaired insulin resistance, high glucose, and reduced metabolism. In both groups, these effects were associated with epigenetic changes that resulted in altered expression of genes related to metabolism and circadian rhythm. Once air pollution was removed from the environment, mice showed improved metabolic health and epigenetic changes were reversed within eight weeks.
The study suggests that cardiometabolic health effects of air pollution are reversible, and the researchers call for studies in humans to verify their findings. If confirmed, results may have important implications for interventions to reduce air pollution.
Citation: Rajagopalan S, Park B, Palanivel R, Vinayachandran V, Deiuliis JA, Gangwar RS, Das LM, Yin J, Choi Y, Al-Kindi S, Jain MK, Hansen KD, Biswal S. 2020. Metabolic effects of air pollution exposure and reversibility. J Clin Invest; doi:10.1172/JCI137315 [Online 11 August 2020].