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Honglei Chen, M.D., Ph.D.

Senior Investigator

Epidemiology Branch / Aging & Neuroepidemiology Group


Building 101, Room A324
111 T.W. Alexander Drive
Research Triangle Park, NC 27709


Research Topics

Dr. Chen's current research focuses on Parkinson's disease, which affects over 1 million older adults in the U.S. He works on several large prospective cohorts to ascertain the environmental and genetic causes of Parkinson's disease and to characterize high risk population through research on non-motor symptoms and biomarkers. The ultimate goal is disease prevention and more effective clinical management.

Dr. Chen's primary research interests include:

  • Environments, Genes, and Gene-environment interactions in the etiology of Parkinson's disease: Genes and environmental factors, alone or in combination, contribute to the pathogenesis of Parkinson's disease. Over the past several years, his research has contributed to a better understanding of the role of environmental factors in Parkinson's etiology. For example, he reported that long duration of smoking, rather than smoking intensity, might underlie the lower risk of Parkinson's disease among smokers (Chen et al., Neurology 2010). He and collaborators also found that moderate to vigorous exercise (Xu et al., Neurology 2010), ibuprofen use (Chen et al., Annals Neurol 2005; Gao et al., Neurology 2011), and higher plasma urate (Chen et al., Am J Epidemiol 2009) were each associated with a lower risk of Parkinson's disease. In collaboration with an international consortium and others, he contributed to the identification of multiple genetic loci that affected the risk of late-onset Parkinson's disease (Simón-Sánchez et al., Nat Genet 2009; IPDGC, Lancet 2011) and the first gene-environment interaction that was identified in a genome-wide approach (Hemza et al., PLoS Genet 2011).
  • Pre-diagnostic non-motor symptoms in Parkinson's disease: Parkinson clinical diagnosis relies on the presence of motor dysfunctions, which do not become apparent until ~50% of the dopaminergic neurons have died. This may partially explain the failure of neuro-protection or disease modification trials for Parkinson's disease that all intervene after diagnosis. Over the past decade, it has become clear that Parkinson's patients also suffer from a variety of nonmotor symptoms, and some (e.g. smell loss, daytime sleepiness) may predate Parkinson's clinical motor onset. Dr. Chen's group therefore is working on characterizing these symptoms in older adults with the hope to identify a pre-diagnostic window where disease modification may be more realistic. He and collaborators have reported that depression (Fang et al., Mov Disord 2010), daytime sleepiness (Gao et al., Am J Epidemiol 2011), constipation (Gao et al., Am J Epidemiol 2011), and erectile dysfunction (Gao et al., Am J Epidemiol 2007) were associated with future risk of Parkinson's disease mostly in a time dependent manner. In the future, Dr. Chen plans to evaluate more systematically nonmotor symptoms alone or in combination in relation to Parkinson's diagnosis and how environment and genetic factors may alter the progression from preclinical to clinical Parkinson's disease.


Chen earned his M.D. from TianJin Medical University in TianJin, China, and Master's degree from the Chinese Academy of Preventive Medicine in BeiJing, China. In 2001, he earned his Ph.D. in Nutritional Epidemiology from Tufts University in Boston, MA and then worked as a Research Fellow and Instructor at the Harvard School of Public Health. He joined the NIEHS Epidemiology Branch as a Tenure-Track Investigator in 2005.

Selected Publications

  1. Chen H, Jacobs E, Schwarzschild MA, McCullough ML, Calle EE, Thun MJ, Ascherio A. Nonsteroidal antiinflammatory drug use and the risk for Parkinson's disease. Ann Neurol. 2005;58(6):963-7.
  2. Alonso A, Huang X, Mosley TH, Heiss G, Chen H. Heart rate variability and the risk of Parkinson disease: The Atherosclerosis Risk in Communities study. Ann Neurol. 2015;77(5):877-83.
  3. Chen H, Huang X, Guo X, Mailman RB, Park Y, Kamel F, Umbach DM, Xu Q, Hollenbeck A, Schatzkin A, Blair A. Smoking duration, intensity, and risk of Parkinson disease. Neurology. 2010;74(11):878-84.
  4. Xu Q, Park Y, Huang X, Hollenbeck A, Blair A, Schatzkin A, Chen H. Physical activities and future risk of Parkinson disease. Neurology. 2010;75(4):341-8.
  5. Liu R, Umbach DM, Peddada SD, Xu Z, Tröster AI, Huang X, Chen H. Potential sex differences in nonmotor symptoms in early drug-naive Parkinson disease. Neurology. 2015;84(21):2107-15.
This page was last updated on April 10th, 2013