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About Sickkids
About SickKids

Padmaja Subbarao, MD, MSc, FRCP (C)

The Hospital for Sick Children
Staff Respirologist
Respiratory Medicine

Research Institute
Senior Scientist
Translational Medicine

University of Toronto
Associate Professor
Dept. of Paediatrics

Phone: 416-813-2196
Fax: 416-813-6246
Email: padmaja.subbarao@sickkids.ca

Research Interests

  • asthma
  • epidemiology
  • intervention studies
  • infant pulmonary function
  • respiratory medicine

Research Activities

Currently asthma and cystic fibrosis are the most common causes for hospitalization in children. Unfortunately little is known about how these diseases are initiated, although, we do agree that the symptoms and pathology start in infancy. Despite this we have no way of detecting airway disease in infants other than x-ray and clinical symptoms. There is increasing evidence, at least in CF, that there is significant disease in the airways prior to the development of clinical symptoms. In older children, we can detect some of this airway pathology by using lung function tests. These tests help us diagnose and assess response to treatment in children. Until the last five years, however, it has been impossible to use lung function tests in infants.

However, the technology is now available to perform a range of lung function tests in infants. With the advent of this technology, we may now be able to earlier diagnose and more effectively manage early airway disease associated with asthma and cystic fibrosis. In so doing, we may effectively, reduce the burden of disease in these children.

My primary research interest is in the early determinants and development of asthma. I am specifically studying changes in infant lung function biomarkers of inflammation in this understudied group to elucidate the effect of environment and specifically viruses on the development of early disease.

I am also the Deputy Director and Co-Principal Investigator of the Canadian Healthy Infant Longitudinal Development (CHILD) Study, a prospective birth cohort of 5000 pregnant women to investigate the role of the environment in the development of asthma.  My particular interest in the study started with its design and as Toronto Site leader, I am also in charge of the infant pulmonary function subcohort which focuses on the specific role viruses and the environment play on the development of lung dysfunction and airway inflammation.  This subcohort will be the largest study to document objective measures of infant lung function and airway inflammation in infants and the only one to document the effect viruses and the environment on infant lung function.


2009-2014: Canadian Institutes of Health Research - Salary Award ($300,000) 

2003-04: Canadian Institutes of Health Research Fellowship - Infant Pulmonary Function Training Fellowship

2000-2001: Canadian Lung Association Research Fellowship - Asthma Research Fellowship


Debley J, Stanojevic S, Filbrum AG, Subbarao P.  Bronchodilator Responsiveness in Wheezy Infants and Toddlers. Pediatr Pulmonol. 2011 Oct 17. [Epub ahead of print]. 

Scott JA, North ML, Rafi M, Huang H, Pencharz P, Subbarao P, Belik J, Graseman H.  Asymmetric Dimethylarginine is Increased in Asthma.  Am J Respir Crit Care Med. 2011 Oct 1;184(7):779-85. 

Wu AC, Tantisira K, Li L, Schuemann B, Weiss ST, Fuhlbrigge AL; Childhood Asthma Management Program Research Group. Predictors of symptoms are different from predictors of severe exacerbations from asthma in children.  Chest.  2011 Jul;140(1):100-7.

Amin R, Subbarao P, Lou W, Jabar A, Balkovec S, Jensen R, Kerrigan S, Gustafsson P, Ratjen F.  The effect of Dornase Alfa on ventilation inhomogeneity in patients with Cystic Fibrosis.  European Respiratory Journal.  2011; 37(4): 806-812.  (CPA) R

Amin R, Subbarao P, Jabar A, Balkovec S, Jensen R, Kerrigan S, Gustafsson P, Ratjen F. Hypertonic saline imporves LCI in pediatric CF patients with normal lung function. Thorax. 2010; 65(5): 379-83. 

Subbarao P, Mandhane PJ, Sears MR. Asthma: epidemiology, etiology and risk factors. CMAJ. 2009; 181(9): E181-90. 

Subbarao P, Becker A, Brook JR, Daley D, Mandhane PJ, Miller G, Turvey S, Sears MR. Epidemiology of asthma: risk factors for development. Expert Rev Clin Immunol. 2009; 5(1): 77-95. 

MacLean J, Kirby M, MacLusky IM, Grasemann H, Subbarao P. Longitudinal analysis of lung function in a population of children with Sickle Cell Disease. Am J Respir Crit Care Med. 2008; 178(10): 1055-9. 

Subbarao P, Sears MR. The chicken or the egg? Perhaps the egg. Arch Dis Child. 2008; 93(7): 552-3. 

Duong M, Subbarao P, Adelroth E, Otis J, Obminski G, Strienich T, Inman M, Pedersen S, O'Byrne PM. Sputum Eosinophils and the Response of Exercise-Induced Bronchoconstriction to Corticosteroid in Asthma. Chest. 2008; 133(2) 404-11. 

Subbarao P, Balkovec S, Solomon M, Ratjen F. Pilot study of safety and tolerability of inhaled hypertonic saline in infants with cystic fibrosis. Pediatr Pulmonol. 2007: 42(5) 471-6. 

Subbarao P, Duong M, Adelroth E, Otis J, Obminski G, Inman M, Pedersen S, O'Byrne PM. Effect of ciclesonide dose and duration of therapy on exercise-induced bronchoconstriction in patients with asthma. J Allergy Clin Immunol. 2006; 117(5): 1008-13. 

Subbarao P, Ratjen F. B2 Agonists for Asthma: the pediatric perspective. Clin Rev Allerg Immunol. 2006; 31(2-3): 209-18. 

Subbarao P, Hulskamp G, Stocks J. Limitations of electronic compensation for measuring plethysmorgraphic airway resistances in infants. Pediatr Pulmonol, 2005; 40(1):45-52. (PA)