Endurance training improves arterial stiffness in COPD patients

The March 21010 issue of Chest, a scientific journal published by the American College of Chest Physicians, includes an article detailing the study results of a team that examined the impact of endurance training on arterial stiffness in COPD patients. (Vivodtzev, I, et al. Significant Improvement in Arterial Stiffness After Endurance Training in Patients with COPD. Chest. 2010; 137(3): 585-592)

According to the article authors, arterial stiffness is considered an indicator of cardiovascular risk and has been shown to be elevated in COPD patients. Additionally, the authors note that the severity of emphysema is somewhat related to the degree of arterial stiffness.

The study involved 17 COPD moderate-to-severe patients who underwent a 4-week aerobic exercise program in which they performed cycling exercises 5 days a week for 18-30 minutes each session. Over the course of the program, intensity and duration of the cycling was increased based on individual COPD patient tolerance (determined by their self-reported shortness of breath) – the average intensity of exercise ranged from just under 40% of peak maximum exertion up to 65% of the same metric. The study’s 4 week program was similar in construction to regimens followed in pulmonary rehabilitation programs although it was shorter in duration but higher in intensity (pulmonary rehab programs are typically 8-12 weeks in duration and patients typically exercise 2-3 times a week, not 5 times as done in this study).

Interestingly, the average improvement in reduced arterial stiffness across the COPD patient population that participated in the exercise program was 10% - a comparable level to the reduction in arterial stiffness achieved by taking prescription statin drugs.

The researchers also evaluated whether the 4 week exercise program described above had positive impact on blood pressure among the COPD patients in the study. Guess what? Before the training program, 40% of the COPD patients who participated in the training program were diagnosed with hypertension (high blood pressure). After the 4 week program, only 20% of this group still had blood pressure levels considered consistent with a hypertension diagnosis.

Further still, the COPD patients who underwent the 4 week aerobic exercise program saw a 20% improvement in the distance they could walk in 6 minutes (a measure commonly used by pulmonologists to determine patient conditioning level), a 58% increase in quadriceps muscle endurance, and a 20% increase in peak work rate among other metrics evaluated.

In the end, the researchers concluded that, “Thus, the benefits of pulmonary rehabilitation in reducing arterial stiffness in patients with COPD is at least comparable in magnitude to what can be obtained with drug therapies.” Pretty amazing results and another excellent example of exercise as medicine for COPD patients (and smokers).