Pedometers may help achieve exercise goals
By David Dunaief, M.D.
Chronic obstructive pulmonary disease, or COPD, is the third leading cause of mortality in the United States, although it’s not highlighted much in the layman’s press (1).
COPD is an umbrella term that includes emphysema, chronic bronchitis of more than three months for two consecutive years and/or chronic obstructive asthma. It is an obstructive lung disease that limits airflow. The three most common symptoms of the disease involve shortness of breath, especially on exertion, production of sputum and cough. This disease affects 6.7 percent of the U.S. population (2).
It tends to be progressive, meaning more frequent and severe exacerbations over time. Since it is a devastating and debilitating chronic disease with no cure, anything that can identify and prevent COPD exacerbations, as well as comorbidities (associated diseases), is critically important.
What are the traditional ways to reduce the risk of and treat COPD exacerbations? The most important step is to stop smoking, since 80 percent of COPD is related to smoking. Supplemental oxygen therapy and medications, such as corticosteroids, bronchodilators (beta-adrenergic agonists and anticholinergics) and antibiotics help to alleviate symptoms (3).
One of the underlying components of COPD may be chronic inflammation (4). Therefore, reducing inflammation may help to stem COPD exacerbations. There are several inflammatory biomarkers that could potentially help predict exacerbations and mortality associated with this disease, such as interleukin-6 (IL-6), C-reactive protein (CRP), leukocyte (white blood cell) count and fibrinogen (a clotting factor of the blood).
How do we reduce inflammation, which may contribute to exacerbations of this disease? Some drugs, such as statins, work partially by reducing inflammation. They may have a role in COPD. Lifestyle changes that include a high-nutrient, anti-inflammatory diet and exercise may also be beneficial.
Let’s look at the evidence.
Biomarkers for inflammation
In a population-based study with over 60,000 participants, results show that as three biomarkers (CRP, leukocyte count and fibrinogen) were elevated, the risk of COPD exacerbation increased in a linear manner (5). In other words, the risk of frequent exacerbation increased 20, 70 and 270 percent within the first year as the number of elevated biomarkers increased from one to three, compared to patients who did not have biomarker elevations.
As time progressed beyond the first year of follow-up, risk exacerbation continued to stay high. Patients with all three biomarkers elevated for longer periods had a 150 percent increased risk of frequent exacerbations. These predictions were applicable to patients with stable and with mild COPD.
In an observational study, results showed that when the biomarker IL-6 was elevated at the start of the trial in stable COPD patients, the risk of mortality increased almost 2.7-fold (6). Also, after three years, IL-6 increased significantly. Elevated IL-6 was associated with a worsening of six-minute walking distance, a parameter tied to poor physical performance in COPD patients. However, unlike the previous study, CRP did not show correlation with increased COPD exacerbation risk. This was a small trial, only involving 53 patients. Therefore, the results are preliminary.
These biomarker trials are exciting for their potential to shape treatments based on level of exacerbation risk and mortality, creating more individualized therapies. Their results need to be confirmed in a randomized controlled trial (RCT). Many of these biomarkers mentioned in the two trials are identifiable with simple blood tests at major labs.
Statins have been maligned for their side effects, but their efficacy has been their strong suit. An observational trial showed that statins led to at least a 30 percent reduction in the risk of COPD exacerbations, with the effect based on a dose-dependent curve (7). In other words, as the dose increased, so did the benefit.
Interestingly, even those who had taken the statin previously saw a significant reduction in COPD exacerbation risk. The duration of statin use was not important; a short use of statins, whether presently or previously, had substantial benefit. However, the greatest benefit was seen in those who had been on a medium to high dose or were on the drug currently. The researchers believe that the mechanism of action for statins in this setting has to do with their anti-inflammatory and immune-modulating effects. This was a retrospective (backward-looking) study with over 14,000 participants. We will need a prospective (forward-looking) study and an RCT to confirm the results.
Exercise is beneficial for almost every circumstance, and COPD is no exception. But did you know that a pedometer might improve results? In a three-month study, those with mild COPD were much more successful at achieving exercise goals and reducing exacerbations and symptoms when they used pedometers, compared to the group given advice alone (8). Pedometers gave patients objective feedback on their level of physical activity, which helped motivate them to achieve the goal of walking 9,000 steps daily. This is a relatively easy way to achieve exercise goals and reduce the risk of COPD exacerbations.
When exercising, we are told to vary our exercise routines on regular basis. One study demonstrates that this may be especially important for COPD patients (9). Results show that nonlinear periodization exercise (NLPE) training is better than traditional routines of endurance and resistance training in severe COPD patients. The goal of NLPE is to regularly alter the time spent working out, the number of sets, the number of repetitions and the intensity of the workout on a regular basis.
This study was randomized, involved 110 patients and was three months in duration. Significantly more severe COPD patients achieved their exercise goals using NLPE than the traditional approach. The group that used NLPE also had an improved quality of life response. The researchers believe that compliance with an NLPE-type program is mostly likely going to be greater because patients seem to enjoy it more.
Chronic inflammation may play a central role in COPD exacerbation. Nonspecific inflammatory biomarkers are potentially valuable for providing more personalized approach to therapy. Drugs that can control inflammation, such as statins, show promise. But don’t forget the importance of lifestyle changes, such as quitting smoking and committing to an exercise regimen that is varied and/or involves the use of a pedometer. And potentially a high-nutrient, anti-inflammatory diet will also contribute positively to reducing the frequency and severity of COPD exacerbations.
(1) Natl Vital Stat Rep. 2011 Dec.;59(10):1-126. (2) cdc.gov. (3) N Engl J Med. 2002;346:988-994. (4) www.goldcopd.org. (5) JAMA. 2013;309:2353-2361. (6) Respiratory Research. 2013;14:24. (7) Am J Med. 2013 Jul;126:598-606. (8) ATS 2013 International Conference: Abstract A1360. (9) Am J Respir Crit Care Med. 2013; online Feb. 28.
Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com.