Saurabh S. Thosar Lab

Saurabh Thosar Lab August 2022
L to R: Megan Jones, Meera Bhide, Saurabh Thosar,
Leandro Campos de Brito, Nicole Chaudhary (Aug. 2022)

About Dr. Thosar

Dr. Saurabh S. Thosar received a professional bachelor’s degree in Occupational Therapy from Seth G.S. Medical College & King Edward Memorial Hospital in India, a clinical master’s degree in Movement Sciences from the University of Illinois at Chicago, and a Ph.D. in Human Performance from Indiana University Bloomington. At Indiana University, Dr. Thosar studied vascular function in response to various stressors, including high-fat diets andphysical inactivity. As a postdoctoral fellow in Dr. Steven Shea’s laboratory at the Oregon Health & Science University, he studied the effects of the circadian system and sleep on cardiometabolic health.
Dr. Thosar is a member of the 
Clinical Physiology and Chronobiology Program 

Research interests

Our laboratory’s broad interests are to study the effects of physical inactivity, circadian rhythms, and sleep on cardiometabolic health. We are also interested in studying how common daily behaviors interact (e.g., daytime physical inactivity affecting nighttime sleep).
Current projects include:

PACE Study:

Randomized crossover trial to study the effects of physical inactivity on sleep and cardiovascular health.
Study diagram: Randomized crossover trial to study the effects of physical inactivity on sleep
and cardiovascular health.

IRB #: 20458; Sedentary Behavior, Cardiovascular Function, and Sleep
We are investigating the effects of sedentary behavior on cardiovascular health (heart rate, blood pressure) and sleep. Specifically,

  1. How chronic physical inactivity affects the cardiovascular system.
  2. How physical inactivity over time affects the quality and duration of sleep.

If you are interested in participating, please access our eligibility survey:
Or email/ call us at / 503-494-4311

Goldilocks Study:

IRB #: 21448; Sleep duration and cardiovascular health

We are investigating how extremes in sleep duration affect cardiovascular health, such as the function/structure of blood vessels, blood biomarkers, and blood pressure. We are also examining the effects of sleep regularization on cardiometabolic health. Results of this study may contribute to a better understanding of how long or short sleep duration is related to cardiovascular risk.

If you are interested in participating, please access our eligibility survey:
Or email/ call us at / 503-494-5536

IAS Study:

IRB #: 15145; Sleep, inactivity, circadian rhythms and cardiovascular risk

We are investigating the separate effects of overnight sleep and physical inactivity that commonly accompanies sleep on cardiovascular variables across the night. At this time, we are specifically looking for participants with mild untreated hypertension.

If you are interested in participating in this research, please email us at


  • Wipfli, B., Wild, S., Hanson, G.C., Shea, S.A., Winters-Stone, K., and Thosar, S.S. (2021). The Active Workplace Study: Protocol for a randomized controlled trial with sedentary workers. Contemporary Clinical Trials 2021 Feb 1:106311. Online ahead of print. PMID: 33539991.
  • Wipfli, B., Wild, S., Donovan, C., Hanson, G.C., and Thosar, S.S. (2021) Sedentary work and physiological markers of health. International Journal of Environmental Research and Public Health. 18(6), 3230. PMID 33804767.
  • Thosar, S. S., Bhide, M. C., Katlaps, I., Bowles, N. P., McHill, A. (2021). Shorter sleep predicts longer subsequent day sedentary duration in healthy midlife adults but not in those with sleep apnea. Nature and Science of Sleep. 11;13: 1411-1418. PMID 34408517
  • Thosar, S. S. & Shea, S. A. (2021). Circadian control of human cardiovascular function. Current Opinion in Pharmacology; 57 (2021): 89-97. PMID: 33610933Thosar S.S., Berman AM, Herzig MX, McHill AW, Bowles NP, Swanson CM, Clemons NA, Butler MP, Clemons AA, Emens JS, Shea SA. (2019). Circadian Rhythm of Vascular Function in Midlife Adults. Arteriosclerosis, Thrombosis, and Vascular Biology. ATVBAHA119312682. PMID 31070470 DOI: 10.1161/ATVBAHA.119.312682
  • Butler, M. P., Thosar, S. S., Smales, C., DeYoung, P. N., Wu H., Hussain, M. V., Morimoto M., Hu K., Scheer F. AJL., and Shea, S. A. (2020). Effects of obstructive sleep apnea on endogenous circadian rhythms assessed during relaxed wakefulness; an exploratory analysis. Chronobiology International. Mar 21: 1-11. PMID: 32192382.
  • Emens, J. S., Berman, A. M., Thosar, S. S., Butler, M. P., Roberts, S. A, Clemons, N. A., Herzig, M. X., McHill, A.W., Morimoto, M., Bowles, N. P. and Shea, S.A (2020). Circadian rhythm in negative affect: Implications for mood disorders. Psychiatry Research 293: 113337. PMID: 32777620.
  • Beaman, A., Bhide, M. C., McHill, A. W., and Thosar, S. S. (2020). Biological pathways underlying the association between habitual long-sleep and elevated cardiovascular risk in adults. Sleep Medicine. 2020 Dec 14;78:135-140.
  • Thosar S.S., Rueda JF, Berman AM, Lasarev MR, Herzig MX, Clemons NA, Roberts SA, Bowles NP, Emens JS, Ellison DH, Shea SA. (2018). Separate and interacting effects of the endogenous circadian system and behaviors on plasma aldosterone in humans. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology. PMID 30521366 DOI: 10.1152/ajpregu.00314
  • Thosar, S. S., Berman, A. M., Herzig, M. X., Roberts, S. A., Lasarev, M. R., Shea, S. A. (2018). Morning impairment in vascular function is unrelated to overnight sleep or the inactivity that accompanies sleep. American Journal of
    Physiology-Regulatory, Integrative and Comparative Physiology. Accepted for publication.
  • Thosar, S. S., Herzig, M. X., Roberts, S. A., Berman, A. M., Clemons, N. A., McHill, A. W., Bowles, N. P., Morimoto,
    M., Butler, M. P., Emens, J. S., Shea, S. A. (2018). Lowest perceived exertion in the late morning due to effects of the
    endogenous circadian system. Epub ahead of print pii: bjsports-2018-099148. PMID: 29475839
  • Thosar, S. S., Butler, M. P., Shea, S.A. (2018). Role of the circadian system in cardiovascular disease: a double-edged
    sword. Journal of Clinical Investigation, 128(6):2157-2167. PMID: 29856365
  • Thosar, S. S., Niederhausen, M., Lapidus, J., et al. (2017). Self-regulated use of a wearable activity sensor is not
    associated with improvements in physical activity, cardiometabolic risk or subjective health status British Journal of
    Sports Medicine. Epub ahead of print. doi: 10.1136/bjsports-2017-098512. PMID: 29222201
  • Parthasarathy, S., Carskadon, M. A., Jean-Louis, G., Owens, J., Bramoweth, A., Combs, D., Hale, L., Harrison, E.,
    Hart, C. N., Hasler, B. P., Honaker, S. M., Hertenstein, E., Kuna, S., Kushida, C., Levenson, J. C., Murray, C., Pack, A.
    I., Pillai, V., Pruiksma, K., Seixas, A., Strollo, P., Thosar, S. S., Williams, N., Buysse, D. (2016). Implementation of
    Sleep and Circadian Science: Recommendations from the Sleep Research Society and National Institutes of Health
    Workshop. SLEEP. 39(12): 2061–2075. PMID: 28201795
  • Berman, Alec M., Thosar, S. S. & Shea, S. A. (2016). Are we underestimating the lifelong benefits of therapy for
    obstructive sleep apnea? Nature and Science of Sleep. 8: 87. PMID: 27051325
  • Thosar S. S., Wiggins, C. C., Shea, S. A, Wallace, J. P. (2015). Brachial artery endothelial function is stable across the
    morning hours in young men. Cardiovascular Ultrasound. 13: 42. PMID: 26438100
  • Thosar, S.S., Bielko, S., Mather, K., Johnston, D., Wallace, J. (2015). Effect of prolonged sitting and breaks in sitting
    time on endothelial function. Medicine and Science in Sports and Exercise. 47(4):843-849. PMID: 25137367
  • Thosar, S. S., Bielko, S. L., Wiggins, C. C., Klaunig, J. E., Mather, K. J., Wallace, J. P. (2015). Antioxidant Vitamin C
    prevents the decline in endothelial function during sitting. Medical Science Monitor. 21: 1015–1021. PMID: 25848890
  • Thosar, S. S., Bielko, S. L., Wiggins, C. C., Wallace, J. P. (2014). Differences in brachial and femoral artery responses
    to prolonged sitting. Cardiovascular Ultrasound. 12:50. PMID 25512175