Objectively measured muscle fatigue in Crohn's disease: correlation with self-reported fatigue and associated factors for clinical application.
OBJECTIVE
The association of fatigue with decreased physical performance and underlying mechanisms are poorly understood in Crohn's disease (CD). We aimed to measure and compare self-reported fatigue with skeletal muscle fatigue in CD subjects and healthy controls, and to identify associated factors that may be amenable to change.


METHODS
Demographic and clinical data were collected and fatigue assessed using the Fatigue Impact Scale (FIS) in 27 consecutive CD patients and 22 matched healthy controls. Circulating cytokines and growth factors were measured. The rate of quadriceps muscle fatigue was assessed using an isokinetic dynamometer as the decrement of force with 30 contractions performed over a 5-minute period.


RESULTS
Compared with healthy controls, CD patients reported greater levels of fatigue (mean global FIS score 45.3 vs 10.5, physical dimension score 12.3 vs 2.7 respectively; each p<0.01) and muscle fatigue (-5.2 vs -1.3 Nm min(-1); p<0.05). The two indices were correlated (r = -0.52 in CD; p<0.01). Patients with CD had lower mean serum IGF-1 levels (16.1 vs 25.4 pmol/L, p<0.01) and higher oxidative stress (TBARS assay 4.3 vs 3.9 μM, p<0.05). On multivariate analysis, low serum vitamin D, IGF-1 and magnesium, and higher IL-6 levels were associated with increased muscle fatigue (all p ≤ 0.05).


CONCLUSIONS
Subjects with CD had more muscle fatigue than matched healthy controls and this correlated well with self-reported fatigue. Of circulating factors that were independently associated with increased muscle fatigue, vitamin D, magnesium and IGF-1 could be targeted in future studies to reduce fatigue and improve physical performance.
Department of Gastroenterology & Hepatology, Eastern Health Clinical School, Monash University, Box Hill, Victoria, Australia. Electronic address: Daniel.van-Langenberg@monash.edu.
D R
DR
van Langenberg
Centre of Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Science, Deakin University, Burwood, Victoria, Australia.
P
P
Della Gatta
Centre of Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Science, Deakin University, Burwood, Victoria, Australia.
S A
SA
Warmington
Centre of Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Science, Deakin University, Burwood, Victoria, Australia.
D J
DJ
Kidgell
Department of Gastroenterology & Hepatology, Eastern Health Clinical School, Monash University, Box Hill, Victoria, Australia.
P R
PR
Gibson
Centre of Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Science, Deakin University, Burwood, Victoria, Australia.
A P
AP
Russell
D000328:Adult; D016022:Case-Control Studies; D003424:Crohn Disease / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D005221:Fatigue / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D005243:Feces / Q000737:chemistry; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D015850:Interleukin-6 / Q000097:blood; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis; D008274:Magnesium / Q000097:blood; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009119:Muscle Contraction / Q000502:physiology; D018763:Muscle Fatigue / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D018384:Oxidative Stress; D052097:Quadriceps Muscle / Q000503:physiopathology*; D057566:Self Report; D019415:Torque; D014807:Vitamin D / Q000097:blood
C583557:IGF1 protein, human; D015850:Interleukin-6; D039841:Leukocyte L1 Antigen Complex; D014807:Vitamin D; D007334:Insulin-Like Growth Factor I; D008274:Magnesium
Fatigue; Inflammatory bowel disease; Skeletal muscle