Changes in lower limb muscle function and muscle mass following exercise-based interventions in patients with chronic obstructive pulmonary disease: A review of the English-language literature

Abstract

Chronic obstructive pulmonary disease (COPD) patients often experience lower limb muscle dysfunction and wasting. Exercise-based training has potential to improve muscle function and mass, but literature on this topic is extensive and heterogeneous including numerous interventions and outcome measures. This review uses a detailed systematic approach to investigate the effect of this wide range of exercise-based interventions on muscle function and mass. PUBMED and PEDro databases were searched. In all, 70 studies (n = 2504 COPD patients) that implemented an exercise-based intervention and reported muscle strength, endurance, or mass in clinically stable COPD patients were critically appraised. Aerobic and/or resistance training, high-intensity interval training, electrical or magnetic muscle stimulation, whole-body vibration, and water-based training were investigated. Muscle strength increased in 78%, muscle endurance in 92%, and muscle mass in 88% of the cases where that specific outcome was measured. Despite large heterogeneity in exercise-based interventions and outcome measures used, most exercise-based trials showed improvements in muscle strength, endurance, and mass in COPD patients. Which intervention(s) is (are) best for which subgroup of patients remains currently unknown. Furthermore, this literature review identifies gaps in the current knowledge and generates recommendations for future research to enhance our knowledge on exercise-based interventions in COPD patients.

Locomotor Muscles in COPD: The Rationale for Rehabilitative Exercise Training

“…Following endurance training alone, isometric quadriceps strength increased by 10 to 21% among studies (De Brandt et al, 2018). However, when data from healthy controls are available, endurance training failed to improve isometric quadriceps strength in both groups (Guzun et al, 2012).…”

“…As recently reviewed by De Brandt et al (2018), resistance training is a particularly effective modality to improve the different muscle strength outcomes (isometric, isokinetic and isotonic strength) in patients with COPD. Isotonic strength of the quadriceps, for instance, increased up to 53% after 12 weeks of this training modality (Ortega et al, 2002).…”

Targeting Limb Muscle Dysfunction in COPD

“…It should be noted that the structural changes mentioned here apply to the quadriceps muscle, and other muscle groups, especially upper limb muscle are not affected to the same extent [20]; thus, limb muscle dysfunction is a heterogenic rather than homogenous process. Furthermore, physiological responses to activities can be different across limb muscles and depending on the type of exercise performed [21][22][23][24][25][26][27].…”

“…Even though non-volitional assessments of muscle strength could be performed through electrical or magnetic stimulation of the muscle or its motor nerve [76], these non-volitional techniques are in a similar way as assessing total body water by deuterium dilution (to determine muscle mass), mainly limited to research centers and clinical research [14]. Non-volitional assessments are also rarely used within COPD research to assess the effect of exercise interventions over time [26]. Thus, voluntary, effort dependent maneuvers, is the most clinically feasible way of measuring limb muscle strength in people with COPD [77].…”

“…Considering the complexity of limb muscle dysfunction in COPD, no single exercise regimen could be used to target all aspects of the decreased function and altered structure of limb muscles [4,26]. In a recent review, the effects of different modalities including aerobic or resistance training, high-intensity interval training, electric or magnetic muscle stimulation, whole-body vibration, and water-based exercise modalities to improve limb muscle function and mass among people with COPD were summarized.…”