1. Kalra, Sanjay MD
  2. Roitman, Jeffrey L. EdD

Article Content


Troosters T, Probst VS, Crul T, Pitta F, Gayan-Ramirez G, Decramer M, Gosselink R


Am J Respir Crit Care Med. 2010;181:1072-1077.


Rationale: Exacerbations of chronic obstructive pulmonary disease (COPD) acutely reduce skeletal muscle strength and result in long-term loss of functional capacity.


Objectives: To investigate whether resistance training is feasible and safe and can prevent deteriorating muscle function during exacerbations of COPD.


Methods: Forty patients (FEV1 49 +/- 17% predicted) hospitalized with a severe COPD exacerbation were randomized to receive usual care or an additional resistance training program during the hospital admission. Patients were followed up for 1 month after discharge. Primary outcomes were quadriceps force and systemic inflammation. A muscle biopsy was taken in a subgroup of patients to assess anabolic and catabolic pathways.


Measurements and Main Results: Resistance training did not yield higher systemic inflammation as indicated by C-reactive protein levels and could be completed uneventfully. Enhanced quadriceps force was seen at discharge (+9.7 +/- 16% in the training group; -1 +/- 13% in control subjects; P = 0.05) and at 1 month follow-up in the patients who trained. The 6-minute walking distance improved after discharge only in the group who received resistance training (median 34; interquartile range, 14-61 m; P = 0.002). In a subgroup of patients a muscle biopsy showed a more anabolic status of skeletal muscle in patients who followed training. Myostatin was lower (P = 0.03) and the myogenin/MyoD ratio tended to be higher (P = 0.08) in the training group compared with control subjects.


Conclusions: Resistance training is safe, successfully counteracts skeletal muscle dysfunction during acute exacerbations of COPD, and may upregulate the anabolic milieu in the skeletal muscle.


Editor's Comment. Muscle related issues in acute respiratory illnesses, both in and out of the intensive care unit, are belatedly starting to get some deserved attention. Acute exacerbations of COPD (AECOPD) are predictably accompanied by decreased muscle strength through mechanisms including systemic inflammation, nutritional deficiencies, the effects of corticosteroids, and the consequences of inactivity. Electrical stimulation has been used in the ICU setting to prevent/reverse some of this decline in muscle function, and this elegant study adds resistance training to the available arsenal. Forty patients (36 completed) with AECOPD were randomized to usual care or a systematic program of lower extremity resistance training; the impact on quadriceps force and 6-minute walk distance (6MWD) were the primary outcomes studied. In addition, inflammatory and metabolic markers were examined. Resistance training protected muscle strength (compared to usual care), produced an improvement in the 6MWD that was sustained for 30 days after dismissal, and did not seem to provoke inflammation systemically or in the muscles. There was also a measurable shift in metabolic markers to suggest an anabolic effect from exercise. Despite the additional intervention, there was no increase in the hospital length of stay. However, none of this translated into a decrease in hospital readmission rate, something that is clearly dependent on far more than quadriceps strength and function alone.





Seymour JM, Moore L, Jolley CJ, Ward K, Creasey J, Steier JS, Yung B, Man WD-C, Hart N, Polkey MI, Moxham J


Thorax. 2010;65:423-428.


Background: Exacerbations of chronic obstructive pulmonary disease (COPD) are characterised by increased dyspnoea, reduced quality of life and muscle weakness. Re-exacerbation and hospital admission are common. Pulmonary rehabilitation (PR) administered after hospital admission for an exacerbation can improve quality of life and exercise capacity.


Objective: To determine whether outpatient post-exacerbation PR (PEPR) could reduce subsequent hospital admission episodes.


Methods: Patients admitted to hospital for an exacerbation of COPD were randomised to receive either usual follow-up care (UC) or PEPR after discharge. Hospital admission and emergency department attendances for COPD exacerbations were recorded over a 3-month period and analysed on an intention-to-treat basis. Secondary outcomes included exercise capacity and quadriceps strength.


Results: 60 patients underwent concealed randomisation at the time of their hospital discharge (UC: n = 30, mean (SD) age 65 (10) years, forced expiratory volume in 1 s (FEV1) 52 (22)% predicted; PEPR: n = 30, 67(10) years, 52 (20)% predicted). The proportion of patients re-admitted to hospital with an exacerbation was 33% in the UC group compared with 7% in those receiving PEPR (OR 0.15, 95% CI 0.03 to 0.72, p = 0.02). The proportion of patients that experienced an exacerbation resulting in an unplanned hospital attendance (either admission or review and discharge from the emergency department) was 57% in the UC group and 27% in those receiving PEPR (OR 0.28, 95% CI 0.10 to 0.82, p = 0.02).


Conclusions: Post-exacerbation rehabilitation in COPD can reduce re-exacerbation events that require admission or hospital attendance over a 3-month period.


Editor's Comment. It is increasingly recognized that targeted pulmonary rehabilitation (PR), by delivering treatment to those most likely to benefit, has important advantages over a less discriminating selection of recipients. Patients with COPD recovering from an acute exacerbation constitute an especially relevant group in this context. It is already known that pulmonary rehabilitation delivered to such patients has a useful impact on exercise tolerance and quality of life; the impact on disease events-subsequent exacerbations requiring hospital evaluation or re-admission-is less clearly defined.


This study reports on 60 patients who were randomized to receive either usual care (UC) or post-exacerbation PR (PEPR) following an acute exacerbation of COPD (AECOPD). Even with these relatively small numbers of patients, there were clear differences between the groups: the PEPR patients had a 7% readmission rate compared to 33% in the UC group, and the frequency of any hospital-evaluation requiring event in the PEPR group was only half that of the control UC group (27% vs 57%). These differences lend further support to the use of PR in patients who are especially likely to benefit and is useful support for trends already underway in clinical practice. In fact, under the pressure of reimbursement rules, patients almost require an AECOPD to qualify for PR in the United States, a perhaps overly restrictive entry criterion.





Owen N, Healy GN, Matthews CE, Dunstan DW


Exerc Sport Sci Rev. 2010;38(3):105-113. doi:10.1097/JES.0b013e3181e373a2


Even when adults meet physical activity guidelines, sitting for prolonged periods can compromise metabolic health. Television (TV) time and objective measurement studies show deleterious associations, and breaking up sedentary time is beneficial. Sitting time, TV time, and time sitting in automobiles increase premature mortality risk. Further evidence from prospective studies, intervention trials, and population-based behavioral studies is required.



Bassett DR Jr, Freedson P, Kozey S


Exerc Sport Sci Rev. 2010;38(3):101-102. doi:10.1097/JES.0b013e3181e373ee


Prolonged sitting is hazardous to one's health. In 1700 Italy, Ramazini observed that sedentary tailors were not as healthy as active messengers. In the 1950s, the first epidemiological study using occupational activity to define sedentary and active behavior was conducted by Morris and colleagues. In this study, bus conductors who climbed approximately 600 stairs per day at work had half the number of heart attacks in comparison to bus drivers who spent 90% of their work time sitting. More recently, a wealth of evidence has arisen indicating that postural fixity (either sitting or standing) is undesirable from a health standpoint. A review article by Neville Owen, Ph.D., and colleagues in this issue of Exercise and Sport Sciences Reviews reports on "Too Much Sitting: The Population-Health Science of Sedentary Behavior." Their article expands on information presented in a lecture by Owen at the 2009 American College of Sports Medicine (ACSM) Annual Meeting and helps to strengthen the link between sedentary behavior and ill health.



Healy GN, Dunstan DW, Cerin E, Shaw JE, Zimmet PZ, Owen N


Diabetes Care. 2008;31:661-666. doi:10.2337/dc07-2046.


Objective: Total sedentary (absence of whole-body movement) time is associated with obesity, abnormal glucose metabolism, and the metabolic syndrome. In addition to the effects of total sedentary time, the manner in which it is accumulated may also be important. We examined the association of breaks in objectively measured sedentary time with biological markers of metabolic risk.


Research Design and Methods: Participants (n = 168, mean age 53.4 years) for this cross-sectional study were recruited from the 2004-2005 Australian Diabetes, Obesity and Lifestyle study. Sedentary time was measured by an accelerometer (counts/minute-1 < 100) worn during waking hours for seven consecutive days. Each interruption in sedentary time (counts/min >=100) was considered a break. Fasting plasma glucose, 2-h plasma glucose, serum triglycerides, HDL cholesterol, weight, height, waist circumference, and resting blood pressure were measured. MatLab was used to derive the breaks variable; SPSS was used for the statistical analysis.


Results: Independent of total sedentary time and moderate-to-vigorous intensity activity time, increased breaks in sedentary time were beneficially associated with waist circumference (standardized [beta] = -0.16, 95% CI -0.31 to -0.02, P = 0.026), BMI ([beta] = -0.19, -0.35 to -0.02, P = 0.026), triglycerides ([beta] = -0.18, -0.34 to -0.02, P = 0.029), and 2-h plasma glucose ([beta] = -0.18, -0.34 to -0.02, P = 0.025).


Conclusions: This study provides evidence of the importance of avoiding prolonged uninterrupted periods of sedentary (primarily sitting) time. These findings suggest new public health recommendations regarding breaking up sedentary time that are complementary to those for physical activity.


Editor's Comment. I've included 3 articles this month. One is a research article, one is a research review, and the other is editorial commentary that accompanied the publication of the review article. I believe that these are 3 of the most important and timely articles that have been featured in this column this year. The "science" of sedentary behavior is in its infancy. There is a long and well-documented history of research documenting the fact that higher levels of physical activity and physical fitness are preventive for many chronic diseases, including heart disease, diabetes, and obesity. These articles, 1 from 2008 and the other 2 from July 2010, demonstrate not only is activity related but also that sedentary time and even "breaks" in sedentary time are also related to disease prevention. That is, sitting for long periods of time raises the risk for these (and presumably other) chronic diseases irrespective of the levels of physical activity or physical fitness.


The science of sedentary behavior referenced in the first article is demonstrated in the research that addresses this important issue. The purpose for including these articles is simply that we, as exercise and cardiopulmonary rehabilitation (CPR) professionals, should begin to directly address these issues with patients. It is almost certain that virtually every CPR program provides patients with home exercise prescriptions, both at discharge from any procedure or inpatient program and during the course of outpatient CPR. Most exercise professionals are aware (or should be) that noncompliance with these prescriptions is more common than not. This is especially true when the reimbursable sessions of CPR end. The literature clearly demonstrates high recidivism (noncompliance) in nonsupervised exercise in patients who exercise in a supervised program.


This information may provide a potential source of "prescribed" physical activity that may be easier to promote, easier for patients to comply with, and effective for prevention and risk factor modification. It is likely that the research will demonstrate the efficacy of increasing physical activity (irrespective of regular cardiovascular endurance exercise) and physical fitness for preventing these diseases. The efficacy of decreasing sedentary behavior and of taking breaks from sedentary time is a third way to "prescribe" activity in our preventive efforts.


I am suggesting that CPR professionals consider providing patients with information and actual activity prescriptions for increasing daily physical activity levels (outside the bounds of supervised or unsupervised "exercise" sessions), with suggestions and recommendations for increasingly regular breaks from times that are sedentary and/or sitting. I am not aware of any "guidelines" for this, but these prescriptions cannot be incorrect if we provide safe, reasonable, and individualized recommendations for patients. Prescribing decreased sedentary behaviors, along with increased physical fitness and physical activity, could be an excellent step in helping patients prevent subsequent events and in promoting physical activity in general.