Medical Conference Notes
At a recent conference of the American College of Chest Physicians held in Canada some of the topics discussed there were relevant to COPD. With regard to the venue, one might ask why hold an “American” chest physician meeting outside the United States? First, the ACCP meeting is an international meeting where people from all over the world come to exchange information about the latest clinical aspects of respiratory illness. Canada, itself, has a rich history of outstanding contributors to the understanding of
From a COPD standpoint a main theme at the conference was “inflammation”. I’m sure many of you have been told at one point that part of an acute medical problem you are suffering from is due to inflammation. It seems every illness has its own degree of inflammation associated with it. Sometimes I wonder if we take for granted that non physicians understand what “inflammation” means. Inflammation is a response produced by your body to an insult or irritation. Among possible inciting factors are infection, allergy or body injury from things such as trauma, burns or exposure to noxious stimuli (such as cigarette smoke). Another category is autoimmune disease where the body reacts against itself. In all of these situations the body mobilizes its defense mechanisms to fight something that is perceived as foreign or has the potential to harm normal tissue. It is most often a beneficial limited reaction in which the noxious stimulus is contained and eradicated at which times the inflammatory system shuts off. Fever is an example of an anti-inflammatory reaction; that is why anti inflammatories are taken to bring the temperature down. However, there are times when the inflammatory reaction becomes over vigilant and does not turn off. At these times there is no imminent threat, yet the inflammatory process continues. It is kind of a “friendly fire” situation. At this point inflammation is damaging the body instead of protecting it. Inflammation can be acute and fulminant or chronic but progressive. An extreme example of acute inflammation is when one goes into “shock.” In this situation not only is the original insult causing a problem, the inflammatory reaction is so exuberant it is actually worsening the situation. An example of chronic inflammation is rheumatoid arthritis which is chronic inflammation of the joints. It is now known that inflammation in the airways is what drives asthma.
In COPD the lung also affected by the inflammation which is provoked by a variety of stimuli, but most commonly of course, cigarette smoke. In Emphysema, chronic inflammation drives slow but relentless tissue injury. Inflammation is a very complex and elaborate network with many different cell types interacting with each other to produce a harmful result. Hopefully, the clinical application of this information will be that eventually, there will be drugs made that will affect specific parts of the inflammatory cascade within the lungs and attenuate its damage.
There continues to be interesting trends in the epidemiology of COPD. As has been noted many times, the number of newly diagnosed cases of COPD is growing rapidly. COPD is a disease frequently diagnosed in the 5th and 6th decades of life. This fact, coupled with the fact that the number of people who comprise this group is growing, makes this a very important demographic to follow. In the year 2002, 1 out of 10 people over 60 years old had COPD. In the not to distant future, 1 in 5 will have some degree of emphysema. COPD carries a very high burden in older people. Twenty-seven percent of the general population smoke, and of those, 15% have COPD. However, in the older range the percentage of people who smoke and have COPD is higher. In addition, the degree that COPD affects women is changing. For instance, in the year 2003, the number of women who died of COPD exceeded that of males. Females now have a higher rate of COPD than men in the 20 to 44 age range. This may be in part due to for a given rate of cigarette exposure, the decline if lung function in women is larger than that of males.
Laurence G. Nair, MD
Pulmonary and Critical Care Medicine