The effects of pulmonary rehabilitation on bone mineral density in patients diagnosed with chronic obstructive pulmonary disease

Abstract

Pulmonary Rehabilitation (PR) is a fundamental intervention for managing Chronic Obstructive Pulmonary Disease (COPD) with exercise training as its key component. COPD patients have a high prevalence of osteopenia and osteoporosis, primarily due to glucocorticosteroid use, which significantly increases their risks of falls and fractures and associated adverse consequences. Evidence regarding the effects of PR on Bone Mineral Density (BMD) in COPD patients is notably limited. Therefore, the aim of this study was to investigate the effects of PR on BMD, fall and fracture risks, and functional exercise capacity in patients with COPD. A quasi-experimental randomised controlled trial was adopted. 31 participants diagnosed with COPD were recruited and allocated to either the active group (n=17) which received a 16-week PR programme followed by a 36-week home exercise programme (HEP) or the control group (n=14) which did not receive the PR programme and the following HEP. All participants underwent the following assessments at baseline: BMD measurements using a DEXA scan, functional mobility level and fall risk assessed using the Timed “Up and Go” test, functional exercise capacity using the 6-minute walk test and 10-year probability of hip and major osteoporotic fractures predicted using the FRAX tool. These assessments were repeated at weeks 16 and 52, except for BMD measurements, which were reassessed only at week 52. Clinically and statistically significant improvements in the 6-minute walk distance (p = .007) and non-statistically significant improvements in functional mobility and reduction of fall risk were observed in the active group after the PR programme. Preservation of femoral neck BMD and improved lumbar spine BMD were shown in the active group from baseline to week 52, alongside reduced fracture and fall risk and significant functional mobility gains (p = .006). Such outcomes were observed to be worse in the control group. As a conclusion, a 16-week PR programme resulted in significant gains in patients diagnosed with COPD, with potential long-term benefits for bone health, making this intervention a potential non-pharmacological strategy for managing BMD loss and preventing fragility fractures in these patients, particularly those on chronic glucocorticosteroids, to help preserve their lung function and functional mobility, lower their healthcare utilisation, and ameliorate their quality of life and long term prognosis.