People
Research Interests
Dr. Hamilton is an international expert in muscle physiology. He focuses on solving some of the most difficult scientific problems about metabolism and biochemistry. This includes determining the effects of sustaining a higher metabolic rate, by oxidative muscle metabolism, for hours throughout the day (not minutes). His laboratory has conducted both basic science research in animal models and translational work in humans to develop and test biomedical strategies for disease prevention across the whole lifespan.
Current experiments involve studying the biochemical mechanisms that may optimize fat metabolism to fuel muscle (when fasting between meals) and also for maximizing glucose metabolism, while also reducing related plasma hyperinsulinemia (after carbohydrate ingestion) and chronic inflammation.
One recent area of focus has been to improve metabolic health for preventing diabetes/pre-diabetes. This includes the goal of improving glucose tolerance because research has shown that this has been a particularly troubling metabolic problem and has proven to be more difficult to treat than most people realize.
Two other areas of related work have been and continue to be: 1) understanding the mechanism why blood triglyceride (fat) metabolism is greatly slowed down during aging in both animals and humans by an LPL-dependent mechanism in slow-twitch oxidative muscles, and, 2) determining how best to reduce chronic inflammatory biomarkers by specific types of muscle contractile activity.
Research has been funded by the NIH, American Diabetes Assoc, American Heart Assoc, National Science Foundation, pharmaceutical companies, and philanthropic support.
His past scientific contributions include illuminating how metabolic and biochemical processes are significantly impacted by certain types of prolonged muscular activity/inactivity. The impact has been measurable since his first proposing the inactivity physiology paradigm in the early 2000’s, with some of his peer-reviewed articles being the most heavily cited in the field. In addition to identifying some of the key underlying mechanisms in research studies, his efforts to lead other scientists studying the impact of muscular inactivity/activity on age-associated chronic diseases (prediabetes/diabetes, cardiovascular health, fat and glucose metabolism) is evidenced by frequently being in high demand as an invited key note speaker for international medical research conferences.
Recent Publications and Research Activity
Studies range from gene expression and molecular mechanisms to the behavioral determinants of chronic disease. Selective examples below:
MT Hamilton, DG Hamilton, TW Zderic. A potent physiological method to magnify and sustain soleus oxidative metabolism improves glucose and lipid regulation. iScience, Volume 25, Issue 9, September 16, 2022. Download the full article (free open access): https://doi.org/10.1016/j.isci.2022.104869. Download Supplemental Results.
Press release: https://stories.uh.edu/2022-soleus-pushup/index.html
Metabolic Innovations Promoting Muscle Metabolism – Reviews and Perspectives
Hamilton MT. The role of skeletal muscle contractile duration throughout the whole day: reducing sedentary time and promoting universal physical activity in all people. J Physiol. 2018 Apr 15; 596(8):1331-1340. doi: 10.1113/JP273284. This article is freely available as a PMC article and on the Journal of Physiology website, https://physoc.onlinelibrary.wiley.com/doi/epdf/10.1113/JP273284
Hamilton MT, Hamilton DG, Zderic TW. The Necessity of Active Muscle Metabolism for Healthy Aging: Muscular Activity Throughout the Entire Day. Progress in Molecular Biology and Translational Science. 2018; 1555:53-68. doi:10.1016/bs.pmbts.2017.12.o14. For the thematic series: Metabolic Aspects of Aging, 2018. This article is freely available from MTH upon requests.
Hamilton M.T., D.G. Hamilton, T.W. Zderic. Role of low energy expenditure and sitting on obesity, metabolic syndrome, type 2 diabetes, and cardiovascular disease. Diabetes 56(11): 2655-2667, 2007. Free full-length article is available from the journal website. http://diabetes.diabetesjournals.org/content/56/11/2655.long
Hamilton MT, Hamilton DG, Zderic TW. Sedentary behavior as a mediator of type 2 diabetes. Med. Sport Sci. 60:11-26, 2014. Free PMC Article. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4364419/
Hamilton, M.T., D.G. Hamilton, T.W. Zderic. Exercise physiology versus inactivity physiology: an essential concept for understanding lipoprotein lipase regulation. Exer. Sports Sci. Rev. 32(4): 161-166, 2004. Free PMC Article. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4312662/
Hamilton, M.T., G.N. Healy, T.W. Zderic, D.W. Dunstan, N. Owen. Too Little Exercise and Too Much Sitting: Inactivity Physiology and the Potential Need for New Recommendations on Sedentary Behavior. Curr. Cardiovasc. Risk Rep., 2(4): 292-298, 2008.
Free PMC Article. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3419586/
Hamilton M.T., and Owen N. Sedentary Behavior and Inactivity Physiology. In: Physical Activity and Health, 2nd edition, C. Bouchard, S.N. Blair, and W. L. Haskell (Eds.). Human Kinetics, 2011.
Owen N., and M.T. Hamilton. Sedentary Time and Obesity. In: Handbook of Obesity - Volume 1: Epidemiology, Etiology, and Physiopathology, Third Edition, G.A. Bray and C. Bouchard (Eds.), CRC Press, Taylor and Francis Group, Boca Raton FL, 367-375, 2014.
Gene Expression and Molecular Regulation of Muscle (representative examples only)
Bey, L. and M.T. Hamilton. Suppression of skeletal muscle lipoprotein lipase activity during physical inactivity: molecular reason to maintain daily low-intensity activity. J. Physiol. 551(2): 673-682, 2003. Free PMC Article. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2343229/
Bey L, N. Akunuri, E.P. Hoffman, P. Zhao, D.G. Hamilton, and M.T. Hamilton. Patterns in global gene expression in rat skeletal muscle during unloading and low-intensity ambulatory activity. Physiol. Genomics 13(2):157-167, 2003.
Zderic TW, Hamilton MT. Identification of hemostatic genes expressed in human and rat leg muscles and a novel gene (LPP1/PAP2A) suppressed during prolonged physical inactivity (sitting). Lipids Health Dis. Oct 12;11:137, 2012. Free PMC Article. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3539950/
Zderic, T.W., and M.T. Hamilton. Physical inactivity amplifies the sensitivity of skeletal muscle to the lipid-induced downregulation of lipoprotein lipase activity. J. Appl. Physiol. 100(1): 249-257, 2006 https://doi.org/10.1152/japplphysiol.00925.2005
Bey L, E. Areiqat, A. Sano, and M.T. Hamilton. Reduced lipoprotein lipase activity in postural skeletal muscle during aging. J. Appl. Physiol. 91(2): 687-692, 2001.
Hamilton, M.T., J. Etienne, W.C. McClure, B.S. Pavey, and A.K. Holloway. Role of local contractile activity and muscle fiber type on LPL regulation during exercise. Am. J. Physiol. 275: E1016-E1022, 1998.
Padilla J, Simmons GH, Davis JW, Whyte JJ, Zderic TW, Hamilton MT, Bowles DK, Laughlin MH. Impact of exercise training on endothelial transcriptional profiles in healthy swine: a genome-wide microarray analysis. Am. J. Physiol. Heart Circ. Physiol. 301(2): H555-H564, 2011.
DeRuisseau, K.C., R.A. Shanely, N. Akunuri, M.T. Hamilton, D.V. Gammeren, A.M. Zergerolglu, M. McKenzie, and S.K. Powers. Diaphragm Unloading via Controlled Mechanical Ventilation Alters the Gene Expression Profile. Am. J. Respir. Crit. Care Med. 15;172(10): 1267-75, 2005.
Bey L., L. Noe., F. Arnault., D. Dabit, P. Maigret, and M.T. Hamilton. Induction of lipoprotein lipase gene expression in 3T3-L1 preadipocytes by atorvastatin, a cholesterol- and triglyceride-lowering drug. Pharmacology 66(1): 51-56, 2002.
Fluck, M,. M.N. Waxham, M.T. Hamilton, and F.W. Booth. Skeletal muscle Ca(2+)-independent kinase activity increases during either hypertrophy or running. J. Appl. Physiol. 88(1): 352-358, 2000.
Campbell, W.G., S.E. Gordon, C.J. Carlson, M.T. Hamilton, and F.W. Booth. Differential global gene expression in red and white skeletal muscle. Am. J. Physiol. Cell Physiol. 280(4): C763-C768, 2001.
Hamilton, M.T., D.R. Marsh, W. Lou, F.W. Booth, and D.S. Criswell. No effect of aging on skeletal muscle insulin-like growth factor mRNAs. Am. J. Physiol. 269 (38): R1183-R1188, 1995.
Metabolism and Muscular Inactivity Behaviors (representative examples only)
Newton RL, Han H, Zderic TW, Hamilton MT. The energy expenditure of sedentary behavior: a whole room calorimeter study. PLoS One May 3;8(5):e63171, 2013. Free PMC Article. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0063171
Craft LL, Zderic TW, Gapstur SM, Vaniterson EH, Thomas DM, Siddique J, Hamilton MT. Evidence that women meeting physical activity guidelines do not sit less: An observational inclinometry study. Int. J. Behav. Nutr. Phys. Act., Oct 4; 9:122, 2012. Free PMC Article. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3490758/
Raichlen DA, Pontzer H, Zderic TW, Harris J, Pontzer H, Mabulla A, Hamilton MT, Wood B. Sitting, squatting, and the evolutionary biology of human inactivity. Proceedings National Academy of Science USA 117 (13) 7115-7121, 2020. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7132251/
Harrison M, Moyna NM, Zderic TW, O'Gorman DJ, McCaffrey N, Carson BP, Hamilton MT. Lipoprotein particle distribution and skeletal muscle lipoprotein lipase activity after acute exercise. Lipids Health Dis., Jul 10;11:64, 2012. Free PMC Article. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3393608/
Júdice PB, Hamilton MT, Sardinha LB, Zderic TW, Silva AM. What is the metabolic and energy cost of sitting, standing and sit/stand transitions? Eur J Appl Physiol. 2016 Feb;116(2): 263-73.
Stephens BR, Granados K, Zderic TW, Hamilton MT, Braun B. Effects of 1 day of inactivity on insulin action in healthy men and women: interaction with energy intake. Metabolism 60(7): 941-949, 2011.
Dunstan DW, Kingwell BA, Larsen R, Healy GN, Cerin E, Hamilton MT, Shaw JE, Bertovic DA, Zimmet PZ, Salmon J, Owen N. Breaking up prolonged sitting reduces postprandial glucose and insulin responses. Diabetes Care 35(5): 976-983, 2012.
Larsen RN, Kingwell BA, Robinson C, Hammond L, Cerin E, Shaw JE, Healy GN, Hamilton MT, Owen N, Dunstan DW. Breaking up of prolonged sitting over three days sustains, but does not enhance, lowering of postprandial plasma glucose and insulin in overweight and obese adults. Clin Sci (Lond). Jul;129(2):117-27. doi: 10.1042/CS20140790, 2015.
Judice PB, Hamilton MT, Sardinha LB, Silva AM. Validity of GT3X and Actiheart to estimate sedentary-time and breaks using ActivPAL as the reference in free-living conditions. Gait and Posture. May;41(4):917-22. doi: 10.1016/j.gaitpost.2015.03.326, 2015.
Barreira TV, Zderic TW, Schuna JM Jr, Hamilton MT, Tudor-Locke C. Free-living activity counts-derived breaks in sedentary time: Are they real transitions from sitting to standing? Gait and Posture. Jun;42(1):70-2. doi: 10.1016, 2015.
Barreira TV, Hamilton MT, Craft LL, Gapstur SM, Siddique J, Zderic TW. Intra-individual and inter-individual variability in daily sitting time and MVPA. J Sci Med Sport 2016; 19(6):476-81. doi: 10.1016/j.jsams.2015.05.004, 2016. Free PMC Article. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4655191/
Howard BJ, Fraser SF, Sethi P, Cerin E, Hamilton MT, Owen N, Dunstan DW, Kingwell BA. Impact on hemostatic parameters of interrupting sitting with intermittent activity. Med. Sci. Sports Exerc. Jul;45(7):1285-1291, 2013.
Granados K, Stephens BR, Malin SK, Zderic TW, Hamilton MT, Braun B. Appetite regulation in response to sitting and energy imbalance. Appl. Physiol. Nutr. Metab. 37(2): 323-333, 2012.
Honors and Awards
Distinguished Alumni Award from the University of South Carolina, Columbia, 2008
Honorary Doctorate of Letters awarded by William Woods University, 2018
Education
B.A. in Zoology at University of Texas-Austin, 1987
M.A. in Exercise Physiology at University of Texas-Austin, 1989
Ph.D. in Exercise Science at University of South Carolina, Columbia, 1994
Postdoctoral Fellowship in Physiology, Cell Biology and Pharmacology at University of Texas School Medical School, Houston, 1997