Nussbaumer-Ochsner Y, Rabe wrote an article in Chest 139 (1), 165-73 (Jan 2011), "Systemic Manifestations of COPD", where he discussed the fact that COPD effects the lungs, yet it also effects the heart, the brain, and even the skin.
He writes that "poorly reversible airflow limitation caused by inflammation is mainly a result from smoking." More recent evidence has caused an evolution of the diagnosis of this disease to more of a "heterogeneous" disorder.
He notes that "extrapulmonary" complications complicate the treatment of the disease. I wrote earlier about end stage COPD, where the heart becomes large because it works so hard to push blood through stiff lungs. This ultimately causes heart failure, or otherwise called Chronic Heart Failure (CHF).
A weakened heart often causes fluid to back up into the lungs, and this causes breathing to become even worse. So now not only does bronchodilator and other hyperinflation therapy become routine treatment, medicines to strengthen the heart, and diuretics, are also indicated.
Likewise, a heart that is overtaxed for many years may revert to an abnormal rhythm called atrial fibrillation. This can become chronic over time. So now medicine must be used to control this rhythm and the rate.
Heart failure often also results in pedal edema, or leg edema. If these comorbidities become severe enough they can effect mobility.
And the more comorbidities associated with COPD the more difficult the management is. For example, diuretics are needed to help get excess fluid from the body may cause electrolyte imbalances that may cause more cardiac arrhythmias, some that may be fatal if not diagnosed and treated right away. Overuse of diuretics may cause renal failure too.
So there is a balancing act. Beta blockers are often used to treat heart failure, yet these meds may cause bronchospasm, especially in asthma and COPD patients.
Heart complications may be attributed either to end state COPD, yet they can also be attributed to smoking. Smoking hardens the arteries and makes the arteries weaker. Smoking also weakens the heart and can cause heart failure.
However, other complications of COPD cannot, Nussbaume writes, cannot be attributed to smoking. These include:
- musculoskeletal wasting
- metabolic syndrome
- weight loss
- muscle wasting
- tissue depletion
He writes that, " The mechanisms underlying weight loss and muscle wasting are incompletely understood but likely involve an imbalance in ongoing processes of protein degradation and replacement. This may include alterations in the relative levels or activities of endocrine hormones such as insulin, growth hormone, testosterone, and glucocorticoids."
The use of steroids may also cause insulin to get out of whack to, and this will cause the physician to require the patient to monitor his sugar and take medicines to treat this too. So all the medicines involve a fine balancing act. You can't do too much of this because it could cause that to go out of whack.
However, it's believed chronic inflammation is a key cause of the lung component of COPD. Now it's believed that chronic inflammation may be systemic more so than just in the lungs. This chronic inflammation may be what causes the extrapulmonary complications.
I'ts believed that "altered" inflammatory mediators may be circulating in the bloodstream of COPD patients, and this may result in "altered" organ function.
I think physicians have known about these other comorbidities for years. I've seen many COPD patients being treated for depression and anxiety. However I'm not sure about the musculoskeletal wasting and the metabolic syndrome.
However, I'm wondering if these might also be complications of the treatment of COPD, thus caused by medicines such as systemic corticosteroid therapy used to treat inflammation.