Studies suggest that approximately 14% to 15% of all patients with COPD who are admitted to the hospital also have diabetes. Does this mean having COPD puts you at greater risk for diabetes? On the contrary, their co-existence most likely has to do with their shared risk factor -- smoking -- which consequentially leads to inflammation.
Inflammation, COPD and Diabetes
There are two types of inflammation -- acute and chronic. Acute inflammation is a short-term immune response to a sudden sustained injury. If you cut your finger, for example, by the next day it is probably going to be red and swollen. This is good news, because it means the inflammatory response has kicked in, releasing a plethora of pro-inflammatory chemicals to fight against foreign invaders possibly introduced into your body by the cut on your finger. The inflammatory response occurs in many different stages, with the end result being healing (in an otherwise healthy person.)
Chronic inflammation, on the other hand, occurs when the inflammatory response won't turn off and the immune system keeps pumping out inflammatory chemicals. It is often the result of certain lifestyle factors -- stress, lack of exercise, poor diet -- that, over time, cause inflammation to occur even when it shouldn't. It is becoming increasingly evident that chronic inflammation is at the root of many chronic diseases, including COPD and diabetes.
What the Research Says
While you may have a greater chance of having co-existing diabetes if you have COPD, there is no prospective data demonstrating that people with COPD have a greater risk of developing diabetes. In fact, an article in Thorax reports that there is a reduction in diabetes in older-aged patients who have COPD. If diabetes is associated with COPD, the greatest effects are seen in the youngest of COPD patients who smoke and those between the ages of 45-55 who have never smoked.
The Effects of High Blood Sugar on COPD
Research has shown that hyperglycemia is linked to impaired lung function. One study showed that diabetes was associated with a lower FEV1 and FVC, an association that was made worse by smoking. The same study found that a increase in fasting blood sugar was associated with a lower residual FEV1.
Why would diabetes and subsequent high blood sugar affect the lungs? Possible links include:
- an increase in body mass index (BMI)
- loss of respiratory compliance (ability of the lungs to distend) associated with diabetes
- damage to the nervous system (diabetic neuropathies)
- weakened respiratory muscles
High blood sugar has also been associated with poor outcomes in hospitalizations due to COPD exacerbation, leading to longer hospital stays and premature death.
Does Smoking Make the Effect of Diabetes on the Lungs Worse?
In people who smoke, the adverse effects of diabetes on lung function are even greater. Diabetics who smoke can minimize the consequences related to smoking by maintaining adequate blood sugar control and reducing risk factors that predispose them to a further decrease in lung function, like smoking or exposure to secondhand smoke.
What Will Improve Your Blood Sugar and COPD?
What else can you do to manage both diabetes and COPD? Let's take a look:
- First and foremost, quit smoking by utilizing a variety of smoking cessation products and the Quit Smoking section in the COPD Forum.
- Start a pulmonary rehabilitation program or other exercise group, which will not only help with blood sugar control, but with improving your COPD symptoms as well.
- Adhere to your medication regimen prescribed by your doctor, whether you have diabetes, COPD, or both.
When Should You Contact the Doctor About Diabetes?
If you have diabetes, make sure you know the signs and symptoms of both hypoglycemia and hyperglycemia. If you experience any of these signs or symptoms, talk to your health care provider as soon as possible. You can also visit About.com's Diabetes GuideSite.
Uchechi N. Iloka, MD and Kathie L. Hermayer, MD, MS.Reviewing the effects of hyperglycemia and diabetes mellitus on COPD. The Journal of Respiratory Diseases. By | March 19, 2010
Emma H Baker MD and Derek Bell MD. Blood glucose: of emerging importance in COPD exacerbations. Thorax 2009;64:830-832.
Johanna R Feary et. al. Prevalence of major comorbidities in subjects with COPD and incidence of myocardial infarction and stroke: a comprehensive analysis using data from primary care. Thorax 2010;65:956e962.