Fatigue in sarcoidosis is variable and may be associated to Vitamin D

Introduction: Fatigue is a common symptom in sarcoidosis. As shown in previous study (Papanikolaou et al, SVLD 2018;35(2):154-9) 25(OH)D deficiency is very common in sarcoidosis; 1,25(OH)2D however is normal or elevated. Aims and Objectives: We hypothesized that levels of fatigue in chronic sarcoidosis may relate to vitamin D metabolism. Methods: Chronic sarcoidosis subjects serially assessed every 3 months for 1 year, each visit corresponding to one season (1 for autumn, 2 for winter, 3 for spring, 4 for summer) where they filled in Fatigue Assessment Scale (FAS) and Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue questionnaires, and tested for 25(OH)D, 1,25(OH)2D, serum calcium and calciuria. Results: 8/15 subjects were males. 53% were on treatment. Mean age 52.5 (±14 ) years old, 6.9 (±3.5) years of disease chronicity and 2.1 (±1.1) organs affected. Fatigue was worse in summer and autumn by FAS and FACIT scales (repeated ANOVA, p 0.002 and 0.001 respectively) (FAS4 27.9±8.9, FACIT4 30.1±10.6). Same seasonal variation for 25(OH)D (25[OH]D4 29.9±3.8 μg/lt, p=0.007) but not for 1,25(OH)2D, calcium and calciuria. Pearson correlation for continuous matched variables showed consistent association between FAS and FACIT scores; temporal associations of FAS1 with 1,25(OH)2D1 (r=0.628, p=0.052), FACIT2 with 1,25(OH)2D1 (r=-0.762, p=0.017), FAS3 with 25(OH)D2 (r=-0.681, p=0.043) and FACIT3 with 25(OH)D2 (r=0.863, p=0.003). Conclusions: In this cohort of chronic sarcoidosis patients, fatigue is worse and 25(OH)D levels are higher during periods of higher sun exposure. FAS scale correlates with FACIT-F scale. An association may exist between level of fatigue, level of 25(OH)D and increased 1,25(OH)2D.