Association of fatigue with an acute phase response in sarcoidosis

The pathophysiological explanation for fatigue, one of the most common symp toms in sarcoidosis, still has to be elucidated, It was hypothesized that t he presence of fatigue is associated with an acute phase response in sarcoi dosis. A cross-sectional study was performed in 38 sarcoidosis patients. Resting e nergy expenditure (REE) nas measured in the fasting state by indirect calor imetry using a ventilated hood and adjusted for fat-free mass (FFM). Patients with fatigue (n=25) also suffered more frequently from other sympt oms, such as exercise intolerance (p=0.01), the need for sleep (p=0.02) and weight loss (p=0.01), compared to those without fatigue (n=13), However, n o relationship,vas found between fatigue and serum angiotensin-converting e nzyme (sACE) or lung function impairment. Patients with fatigue had higher levels of C-reactive protein (CRP) (11.4+/-6.8 mu g.mL(-1), p<0.0001) and R EE adjusted for FFM (33.0+/-3.7 kcal.kg FFM-1. p<0.003) compared to those w ithout fatigue (3.2+/-2.2 mg.mL(-1;) 29.2+/-2.8 kcal.kg FFM-1). Furthermore , REE/FFM was significantly related to CRP (r=0.54, p=0.001). This study confirms the presence of an acute phase response as indicated bg metabolic derangements and a moderate increase in C-reactive protein level s in sarcoidosis, particularly in those patients with constitutional sympto ms. Future studies should focus on the clinical relevance and therapeutic i mplications of these findings.