The relationship between fatigue and clinical parameters in pulmonary sarcoidosis.

OBJECTIVE

Studies on the relationship between fatigue and clinical parameters are sparse. In the present study this relationship was examined in a systematic way.

METHODS

Patients with time since diagnosis < or = 2 years, visiting the outpatient clinic of the University Hospital Maastricht (n = 60; 34 untreated, 26 treated) were clinically evaluated and completed the Fatigue Assessment Scale (FAS). A representative sample of the Dutch population (n = 1893) also completed the FAS. Pulmonary disease severity was estimated from lung function test results and measures of metabolic derangement. Acute phase response markers high-sensitivity C-reactive protein (hs-CRP), serum amyloid A (SAA) and sarcoidosis activity parameters, soluble interleukin-2-receptor (sIL2R), and angiotensin-converting enzyme (ACE) were also measured.

RESULTS

Only 27% of the sarcoidosis patients were diagnosed as non-fatigued (FAS score < 22), compared to 80% in the control population (n = 1893). In the sarcoidosis patients no sex differences and no differences in fatigue scores between the treated and the untreated groups were found. Patients with fatigue (FAS-score > or = 22) had lower DLCO values (p < 0.05). However, none of the tested clinical or serological parameters appeared to be a significant predictor of fatigue.

CONCLUSIONS

In the present study, it was confirmed that fatigue is a major problem in sarcoidosis. The extent of fatigue could not be explained by clinical parameters. Thus, up to now, no clinical or physiological variable seems useful in predicting which patients are fatigued. In this light, the Fatigue Assessment Scale might be considered as a supplementary tool in sarcoidosis.