Tuesday, January 31, 2017

Focus on COPD

Focus on Chronic Obstructive Pulmonary Disease (COPD):

Chronic Obstructive Pulmonary Disease (COPD) is a debilitating and potentially fatal condition affecting over 15 million Americans.  In 2008, chronic lower respiratory disease, of which COPD is the largest primary condition, became the third leading cause of death. This condition is found to be increasing globally with increased numbers of emergency room visits and hospitalizations due to exacerbations of the condition brought on by exposures to irritating gases and particulate matter.  In France alone, the national medical costs in 2012 attributable to COPD amounted to over 670 million euros, an increase of almost 11% since 2007.  In the U.S., the medical costs for COPD in 2010 were over $36 billion dollars.  And these numbers, as well as the number of persons afflicted with this condition, continue to rise.  Eighty percent of the deaths from COPD are attributable to smoking and approximately 60% of persons with COPD are former smokers or live in homes where someone is a smoker.  Clearly, smoking is a major factor in acquiring this disease but for almost 40% of sufferers, smoking was not the primary cause.  Persons living in areas highly polluted by industry or near major traffic areas experience higher than average affliction rates.
There is no cure for COPD and once the condition is diagnosed, the best that can be hoped for is that it can be managed in a manner that minimally affects everyday lives.  But knowing what might be the triggers for episodes, i.e., exacerbations, has been difficult to quantify.  Data that is available is very general.  For instance, persons living in areas that have higher than average pollution levels tend to be affected more readily than persons living in lower pollution areas. But these are very general observations.  What pollutant is responsible? Or is one pollutant more responsible than another and why?  Ozone is known to have an effect and there is a growing body of evidence indicating that fine particles, PM2.5, or their even smaller constituent, ultrafine particles with diameters less than 300 nm, may also play a major role.  Studies in the UK, as well as some studies being proposed for the U.S., hope to shed more light on this problem by tracking individual exposure levels on a daily basis in order to correlate exacerbations with pollutant exposures.
Knowing this type of information can have significant impact not only on reducing the number of emergency room visits and hospitalizations but also on improving the quality of life of persons that are affected.  Using inexpensive pollutant monitors in homes can alert persons to perform simple actions, like closing windows, increasing ventilation, turning on air cleaners, or even replacing furnace and AC filters that can reduce pollutant level and decrease exposures that could have led to exacerbations and the subsequent consequences.  Even though there is still much work to be done to pinpoint and quantify those factors that produce adverse COPD reactions, the outlook is hopeful that these studies can have a major impact on reducing the devastating consequences associated with this condition.

A wealth of additional information can be found on the COPD Foundation website, http://www.copdfoundation.org/.  One of the more comprehensive COPD health care systems is operated by National Jewish Health located in Denver, CO, https://www.nationaljewish.org/programs/directory/copd/, and locally in the Pittsburgh, PA area UPMC maintains a Center for COPD and Emphysema, http://www.upmc.com/services/pulmonology/respiratory/services/copd-and-emphysema-clinical-center/pages/default.aspx, and Allegheny Health Network (AHN) has recently established a Breathing Disorders Center, https://www.ahn.org/news/3-2-2016/allegheny-health-network-establishes-breathing-disorders-center-wexford-health.   
Additionally, links to some current and relevant research on this problem can be found below, as well as a link to a peer review journal dedicated to COPD….

  1. http://bmjopen.bmj.com/content/bmjopen/6/10/e013014.full.pdf
  2. http://bmjopen.bmj.com/content/bmjopen/6/7/e011330.full.pdf
  3. https://respiratory-research.biomedcentral.com/articles/10.1186/s12931-016-0469-6 
  4. https://www.nice.org.uk/guidance/cg101/resources/costing-report-134511805
  5. https://www.dovepress.com/major-air-pollutants-and-risk-of-copd-exacerbations-a-systematic-revie-peer-reviewed-fulltext-article-COPD
  6. https://www.dovepress.com/international-journal-of-chronic-obstructive-pulmonary-disease-journal

Tuesday, January 3, 2017

Particulate Matter and Susceptible Populations:

We often hear warnings about ozone action days or warnings for susceptible segments of the population to stay indoors if the air quality exceeds certain levels.  So, what does it mean to be “susceptible”, or “at-risk population” or “sensitive population?  Who belongs to these groups and why?  In a review article entitled “Particulate Matter – Induced Health Effects: Who is susceptible?” researchers at the National Center for Environmental Assessment at the EPA located in the Research Triangle Park in North Carolina examined the epidemiological data acquired over the past two decades in an effort to explain and quantify susceptible populations.

In their review paper, they divided these populations into several distinct categories:

1.     Life Stage – where, in very general terms persons at the extremes (children and adults over 75 years of age) are found to be more susceptible to PM exposures than the rest of the population;
2.     Sex – And although there have been limited studies addressing this category and no relevant correlations found, it is generally recognized that female respiratory systems are generally smaller and more reactive, factors that could place them at increased risk;
3.     Race and Ethnicity – Some recent studies indicate that there may be some differences but those differences appear to also vary by location and the findings in one geographical region may not be the same as in another geographical region;
4.     Genetic Factors – This category is in its infancy in our understanding of the impact of genetic factors but some genes have already been identified that can significantly affect antioxidant functions in the lung;
5.     Obesity – While studies have shown that exposure to PM increases heart rate variability and higher levels of inflammatory markers in obese persons, some of these results may also be masked by other co-existing and pre-existing conditions;
6.     Preexisting Diseases – By far, those persons with preexisting cardiovascular or respiratory disease form the largest segment of at-risk, susceptible populations. Persons with asthma or COPD exhibit increased adverse reactions to PM exposures as well as those with congestive heart failure or coronary artery disease or other cardiovascular diseases.

The full report can be found at:
http://ehp.niehs.nih.gov/wp-content/uploads/119/4/ehp.1002255.pdf and is well worth reading. It is also important to understand that our definition of susceptible populations is dynamic and evolving. And, more importantly, as the authors also stress, adverse reactions to PM exposure is not relegated to these susceptible groups.  Given certain circumstances and conditions, even the healthiest of those among us can be affected with the real message being to minimize PM exposures for a longer, healthier life.

Dave Litton
Senior Scientist

Airviz, Inc.