title: Fatigue, muscle strength and vitamin D status in women with systemic lupus erythematosus compared with healthy controls.
abstract: Recent studies have demonstrated an inverse relationship between vitamin D levels and fatigue in systemic lupus erythematosus (SLE). The aims of this study were to evaluate proximal muscle strength, fatigue and vitamin D levels in women with SLE compared with healthy controls and to investigate relationships between these factors in a cohort of women with SLE. Forty-five women (24 SLE, 21 healthy controls) participated. Primary outcome measures were the fatigue severity scale (FSS), isometric muscle strength of dominant limbs using hand held dynamometry, two functional tests--the 30-second chair stand test and the 1-kg arm lift test, with vitamin D status measured using 25(OH)D. Overall 25(OH)D levels were 68.4 (22.4) nmol/L with no difference between SLE and control groups. There was a statistically and clinically significant difference in fatigue, 1-kg arm lift, 30-second sit to stand, knee extension, hip flexion, hip abduction, shoulder flexion and grip strength in the SLE group compared with the control group (p < 0.05). In the SLE group FSS was moderately correlated with both functional measures (1-kg arm lift r = -0.42, 30-second chair stand r = -0.44, p < 0.05). However, no statistically significant correlation between dynamometry measures and fatigue was evident. There was no association between fatigue and 25(OH)D level (r = -0.12). In summary, women with SLE were weaker and demonstrated reduced physical function and higher fatigue levels than healthy controls. Fatigue was related to physical function but not vitamin D status or maximal isometric strength in vitamin D replete individuals with SLE.
authors: University of Queensland, School of Medicine, Brisbane, Queensland, Australia. k.stockton@uq.edu.au
authors: K A
authors: KA
authors: Stockton
authors: D A
authors: DA
authors: Kandiah
authors: J D
authors: JD
authors: Paratz
authors: K L
authors: KL
authors: Bennell
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005221:Fatigue / Q000209:etiology*; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000503:physiopathology*; D008875:Middle Aged; D053580:Muscle Strength; D053581:Muscle Strength Dynamometer; D012720:Severity of Illness Index; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D