Clinical Correlates of Reduced Physical Activity in Idiopathic Pulmonary Fibrosis

Abstract

Background: Little is known about the consequences of idiopathic pulmonary fibrosis (IPF) for physical activity (PA). Objectives: We aimed to investigate levels of PA in IPF and to study associations of PA with lung function, exercise capacity, symptoms, and quality of life. Methods: In stable patients with IPF we measured PA (steps per day, SPD; physical activity level, PAL; minutes of moderate activity, MMA) by accelerometry (SenseWear Armband) for 1 week. We also assessed lung function (forced vital capacity, FVC; diffusing capacity for carbon monoxide, D<smlcap>LCO</smlcap>); exercise capacity (6-minute walking distance, 6MWD); dyspnea (modified Medical Research Council, mMRC); fatigue (Multidimensional Fatigue Inventory, MFI-20), and generic (12-Item Short Form Survey, SF-12) and health-related quality of life (St. George's Respiratory Questionnaire) as further clinical variables. Results: We investigated 48 patients with IPF in two centers (mean age, 67 years; 75% male; 23% on long-term oxygen therapy; mean FVC 75%pred.; mean D<smlcap>LCO</smlcap> 43%pred.; mean 6MWD 355 ± 140 m; mean SPD 5,017 ± 3,360). On a bivariate level, all clinical variables were significantly associated with SPD (p < 0.05). The associations of mMRC, MFI-20, SF-12 (physical health), and 6MWD with SPD were independent of impaired lung function (p < 0.05). At multivariate analyses, either 6MWD (total explained variance of the model, total R²: 42%) or MFI-20 (total R²: 39%) were the strongest independent predictors of SPD. Conclusion: Fatigue and exercise capacity are strong and independent predictors of PA in patients with IPF, which suggests that both measures should be assessed when the consequences of IPF for PA in daily life are studied.

Short-Term Effects of a Multimodal 3-Week Inpatient Pulmonary Rehabilitation Programme for Patients with Sarcoidosis: The ProKaSaRe Study

“…This benefit of PR is particularly important, as several studies [8, 15, 21] have shown that exercise intolerance is linked to reduced QoL, dyspnoea, and fatigue, thus frequently creating a persistent vicious circle, as has also been described for other pulmonary diseases [5, 6]. PR can potentially break this circle by increasing exercise capacity and thus enhance physical activity levels in daily life [41]. Moreover, the greatest benefit of PR was seen in the severely exercise-intolerant patients.…”

“…Mutual influences and interlinked physiological training results, such as reduced dyspnoea (MRC), improved physical fitness (6MWD), or reduced fatigue contribute to the improvements in HrQoL after PR. Moreover, 6MWD and SGRQ scores were recently shown to have stronger associations with steps per day, while exercise capacity and QoL measurements were robust predictors of physical activity in patients with sarcoidosis [41]…”

Physical Activity and Fatigue in Patients with Sarcoidosis

“…While one study found physical activity in patients with sarcoidosis and fatigue to be reduced compared to predicted reference values [12], Saligan [11] was not able to show meaningful differences between obese patients with sarcoidosis and sedentary controls. In chronic lung diseases, established clinical parameters such as exercise capacity and lung function, or patient-reported outcomes such as health-related quality of life and generic quality of life, generally show moderate associations with levels of objectively measured physical activity [8][9][10]. However, to the best of our knowledge, those relationships have not yet been investigated in patients with sarcoidosis.…”

“…The armband is worn on the upper left arm over the triceps muscle and incorporates amongst other things a triaxial accelerometer that records the average number of steps per day; those are related to key functional characteristics and quality-of-life measures in chronic obstructive pulmonary disease [10,16], asthma [17], idiopathic pulmonary fibrosis [8], and lymphangioleiomyomatosis [9]. We instructed the patients to wear the armband 24 h a day, except for the time spent on personal hygiene.…”

“…Interestingly, fatigue has recently been linked to objective measures of physical activity in daily life in other chronic lung diseases such as idiopathic pulmonary fibrosis [8], lymphangioleiomyomatosis [9], and chronic obstructive pulmonary disease [10], suggesting that it might also affect physical activity in patients with sarcoidosis. However, studies on objectively measured physical activity in patients with sarcoidosis are rather limited, and the results are conflicting [11,12].…”