Exercise capacity in sarcoidosis. Study of 29 patients

Cardiopulmonary exercise testing in interstitial lung diseases and the value of ventilatory efficiency

Interstitial lung diseases (ILDs) are diverse parenchymal pulmonary disorders, primarily characterised by alveolar and interstitial inflammation and/or fibrosis, and sharing pathophysiological similarities. Thus, patients generally harbour common respiratory symptoms, lung function abnormalities and modified exercise adaptation. The most usual and disabling complaint is exertional dyspnoea, frequently responsible for premature exercise interruption. Cardiopulmonary exercise testing (CPET) is increasingly used for the clinical assessment of patients with ILD. This is because exercise performance or dyspnoea on exertion cannot reliably be predicted by resting pulmonary function tests. CPET, therefore, provides an accurate evaluation of functional capacity on an individual basis. CPET can unmask anomalies in the integrated functions of the respiratory, cardiovascular, metabolic, peripheral muscle and neurosensory systems in ILDs. CPET uniquely provides an evaluation of all above aspects and can help clinicians shape ILD patient management. Preliminary evidence suggests that CPET may also generate valuable prognostic information in ILDs and can be used to shed light on the presence of associated pulmonary hypertension. This review aims to provide comprehensive and updated evidence concerning the clinical utility of CPET in ILD patients, with particular focus on the physiological and clinical value of ventilatory efficiency (V˙_E/V˙_CO2 ).

Efficacy of a Structured Exercise Program for Improving Functional Capacity and Quality of Life in Patients With Stage 3 and 4 Sarcoidosis: A RANDOMIZED CONTROLLED TRIAL

PURPOSE

This study investigated the effects of an exercise program on functional capacity and quality of life in patients with stage 3 and stage 4 sarcoidosis.

METHODS

Eighteen patients with stage 3 and 4 sarcoidosis were recruited; 9 received 12 wk of supervised exercise training and 9 received usual care. Patients underwent the following evaluations at baseline and follow-up: 6-min walk test, maximal inspiratory and expiratory pressure tests, back and leg dynamometer test, modified Medical Research Council Dyspnea Scale, Fatigue Severity Scale, St George Respiratory Questionnaire, Short Form-36 Quality of Life Questionnaire, Hospital Anxiety and Depression Questionnaire, body plethysmography, carbon monoxide diffusing capacity test, and blood gas analysis.

RESULTS

The median (interquartile range) increase in 6-min walk distance in the intervention group was 40 (31-62) m. Improvement in functional capacity; perception of dyspnea; fatigue; anxiety; peripheral and inspiratory muscle strength; partial arterial oxygen pressure; arterial oxygen saturation; and the symptom, activity, and total scores of the St George Respiratory Questionnaire were significantly greater in the intervention group than in the usual care group at follow-up (P < .05).

CONCLUSIONS

Exercise training improves functional capacity, muscle strength, dyspnea, quality of life, anxiety, fatigue, and oxygenation in patients with stage 3 and stage 4 sarcoidosis. Standard treatment of patients with late-stage sarcoidosis should integrate exercise training and pulmonary rehabilitation.

Interrelationship between sleep-disordered breathing and sarcoidosis

Sleep-disordered breathing (SDB) has a high prevalence in sarcoidosis. This high prevalence may be the result of increased upper airways resistance from sarcoidosis of the upper respiratory tract, corticosteroid-induced obesity, or parenchymal lung involvement from sarcoidosis. OSA is a form of SDB that is particularly common in patients with sarcoidosis. Sarcoidosis and SDB share many similar symptoms and clinical findings, including fatigue, gas exchange abnormalities, and pulmonary hypertension (PH). Sarcoidosis-associated fatigue is a common entity for which stimulants may be beneficial. Sarcoidosis-associated fatigue is a diagnosis of exclusion that requires an evaluation for the possibility of OSA. Hypercapnia is unusual in a patient with sarcoidosis without severe pulmonary dysfunction and, in this situation, should prompt evaluation for alternative causes of hypercapnia, such as SDB. PH is usually mild when associated with OSA, whereas the severity of sarcoidosis-associated PH is related to the severity of sarcoidosis. PH caused by OSA usually responds to CPAP, whereas sarcoidosis-associated PH commonly requires the use of vasodilators. Management of OSA in sarcoidosis is problematic because corticosteroid treatment of sarcoidosis may worsen OSA. Aggressive efforts should be made to place the patient on the lowest effective dose of corticosteroids, which involves early consideration of corticosteroid-sparing agents. Because of the significant morbidity associated with SDB, early recognition and treatment of SDB in patients with sarcoidosis may improve their overall quality of life.

Reduction of exercise capacity in sarcoidosis in relation to disease severity

INTRODUCTION

Pulmonary function tests (PFTs) do not always predict functional limitations during exercise in sarcoidosis. Cardiopulmonary exercise testing (CPET) may facilitate the recognition of exercise intolerance in these patients.

AIM

As relevant data in sarcoid patients are limited, the aim of the study reported here was to assess exercise capacity impairment during a maximal CPET and to evaluate potential correlations with PFT measurements and radiological stages of the disease.

METHOD

A total of 83 sarcoid patients consecutively referred for evaluation of exertional dyspnea over a 3-year period were studied retrospectively with PFTs, including spirometry, diffusing capacity of the lung for carbon monoxide (DLCO) and lung volumes, and CPET using standard protocol. Patients were grouped according to their radiological stages: Stage I (n=43), Stages II-III (n=31), and Stage IV (n=9).

RESULTS

Forced expiratory volume in 1 second, forced vital capacity, and total lung capacity were mildly impaired only in Stage IV (means ± standard deviation: 72.44±28.00, 71.33±26.70, and 59.78±21.72, respectively), while DLCO was mildly and moderately reduced in Stages II-III and IV (72.68±14.13 and 51.22±18.50, respectively) and differed significantly between all stages (I vs II-III: P=0.003, I vs IV: P=0.003, and II-III vs IV: P=0.009). Exercise capacity (as expressed by peak oxygen consumption <84% predicted) was decreased in 53% of patients (Stage I: 48%, Stages II-III: 52%, Stage IV: 78%); however, significant differences were noticed only between Stages I and IV (P=0.0025). Of note, significant correlations were found between peak oxygen consumption and DLCO (P=0.0083), minute ventilation (P<0.0001), oxygen pulse (P<0.0001), lactate threshold (P<0.0001), and peak ventilatory threshold (P<0.0001).

CONCLUSION

CPET could be considered a useful tool in exercise intolerance evaluation in sarcoid patients with mild PFT abnormalities. Exercise limitation in sarcoidosis may be attributed to both ventilatory and cardiocirculatory impairment.

Six-Minute Walk Test and Health Status Assessment in Sarcoidosis

BACKGROUND

The 6-min walk test has proved useful in assessing impairment and prognosis in various lung diseases.

METHODS

A prospective study of 142 sarcoidosis patients seen during a 6-week period at one tertiary sarcoidosis clinic. All patients completed spirometry, 6-min walk testing, St. George Respiratory Questionnaire (SGRQ), fatigue assessment scale, and dyspnea score. Parameters assessed included the 6-min walk distance (6MWD) and the initial and lowest oxygen saturations during the test.

RESULTS

One hundred three of 142 patients had extrapulmonary manifestations, 10 patients had left ventricular dysfunction, and 14 patients had documented pulmonary hypertension. Seventy-three patients (51%) completed a 6MWD < 400 m, and 32 patients (22%) walked < 300 m. The 14 patients with documented pulmonary hypertension had a shorter 6MWD (median, 280 m; range, 61 to 404) than those without documented pulmonary arterial hypertension (median, 411 m; range, 46 to 747; p < 0.0001). Several components of the pulmonary function and quality of life correlated with 6MWD. Using a stepwise multiple regression analysis, only SGRQ activity component (t = - 7.498, p < 0.0001), FVC (t = 4.415, p < 0.0001), and lowest oxygen saturation (t = 2.55, p < 0.02) were independent predictors of 6MWD.

CONCLUSIONS

6MWD was reduced in the majority of sarcoidosis patients. Several factors were associated with a reduced 6MWD, including FVC, oxygen saturation with exercise, and self-reported respiratory health. Both 6MWD and quality of life measures are useful in assessing the functional status of sarcoidosis patients.