Dr. Tetyana Kendzerska

2015 CRRN Fellowship Recipient


Supervisor: Dr. Andrea Gershon

Institution: Institute for Clinical Evaluative Sciences/Sunnybrook Research Institute

ResearchGate: https://www.researchgate.net/profile/Tetyana_Kendzerska

LinkedIn: https://www.linkedin.com/in/tetyana-kendzerska-82023639

Modifiable effect of co-existence of obstructive airway diseases (chronic obstructive pulmonary disease, asthma, and obstructive sleep apnea): evidence from clinical and health administrative data

Asthma (reversible airway obstruction), chronic obstructive pulmonary disease ([COPD] irreversible airway obstruction) and obstructive sleep apnea (repetitive upper airway obstruction during sleep) are highly prevalent chronic diseases in the general population. All of them are characterized by airway obstruction. A patient who has features of more than one condition (asthma, COPD or sleep apnea) exhibits an overlap syndrome.

Patients with overlap syndrome may have higher risk of developing adverse long-term outcomes and may require different disease management than patients with asthma, COPD or sleep apnea alone.

The proposed project has two primary research objectives. First, we will investigate the relationship between each of coexisting COPD, asthma and obstructive sleep apnea. Specifically, we will assess the distribution of overlap syndrome over time in the largest Canadian province (Ontario), and we will examine the mortality rate among subjects with overlap syndrome as compared to those having each disease alone. We will then determine whether a history of asthma or COPD affects the risk of development of obstructive sleep apnea, its severity and adverse health long-term consequences such as the development of heart disease(s) and death from all-causes.

Why is the research project/program important?

There are no large population estimates of the distribution of overlap syndrome and its mortality by age and sex over time. Also we don’t know if the joint effect of two or three airway diseases on adverse health consequences over time differs from the independent effects of each of the disease. For example, co-existing diseases may act independently or interact thereby making worse or reducing the effect of one another.

The proposed project is designed to address this knowledge gap using a unique, large, high quality dataset which contains population-based administrative and clinical data that follows patients over time.

Identifying the characteristics and prognosis of individuals with overlap syndrome allows the identification of high-risk groups that benefit from targeted preventive or management strategies that improve health outcomes.

What was the result of the project and what impact will it have?

Preliminary results were reported as oral presentation at the Canadian Respiratory Conference, in Halifax, Nova Scotia, April 14-16, 2016.

Preliminary, we found that the highest hazard of CV disease was observed in COPD patients with significant nocturnal oxygen desaturation, even in patients with mild diurnal hypoxemia. Effect of COPD and nocturnal oxygen desaturation together on CV risk exceeds the effect of each factor considered individually with the largest synergetic effect observed in women.

Considering that about half of patients with COPD and nocturnal hypoxemia had severe OSA, clinicians should be vigilant in establishing the diagnosis of OSA in these patients. Overnight oximetry may be useful in individuals with COPD to exclude significant overnight desaturation that may be associated with reduced survival. Furthermore, patients with COPD who are diagnosed with nocturnal hypoxemia by oximetry should undergo PSG to exclude coexistent OSA as a treatable cause of nocturnal hypoxemia.

In individuals with both COPD and OSA there are clear benefits from continuous positive airway pressure (CPAP) in both survival and risk of hospital admission.


The impact of a history of asthma on long-term outcomes of people with newly diagnosed chronic obstructive pulmonary disease: A population study.
Tetyana Kendzerska, Teresa M. To, Shawn D. Aaron, M. Diane Lougheed, Mohsen Sadatsafavi, J. Mark FitzGerald, Andrea S. Gershon for the Canadian Respiratory Research Network. The impact of a history of asthma on long-term outcomes of people with newly diagnosed chronic obstructive pulmonary disease: A population study. 2016-09 (article in press) DOI: http://dx.doi.org/10.1016/j.jaci.2016.06.026

Tavakoli H., FitzGerald J.M., Chen W., Lynd L., Kendzerska T., Aaron S., Gershon A., Marra C., Sadatsafavi M. for the Canadian Respiratory Research Network. Ten-year trends in direct costs of asthma: a population-based study. Allergy, the European Journal of Allergy and Clinical Immunology (accepted).  

Sadatsafavi M, Tavakoli H, Kendzerska T, Gershon A, To T, Aaron S, FitzGerald JM. History of asthma in patients with chronic obstructive pulmonary disease: a comparative study of economic burden. Annals of the American Thoracic Society, Vol. 13, No. 2 (2016), pp. 188-196

Kendzerska T, Gershon A, Tomlinson G, Leung R. The effect of patient neighbourhood income level on the purchase of continuous positive airway pressure treatment among sleep apnea patients. Ann Am Thorac Soc. 2016;13:93-100. Appeared with accompanying editorial.

Kendzerska T, Leung RS. Going Beyond the Apnea-Hypopnea Index. Chest. 2016;149(5):1349-1350. Correspondence

Kendzerska T, Ayas N. Turning dreams into nightmares: different metabolic impacts of obstructive events in REM vs. NON-REM sleep. Am J Respir Crit Care Med. Editorial 2015;192:1034-1035.