Metabolic and Structural Skeletal Muscle Health in Systemic Lupus Erythematosus–Related Fatigue: A Multimodal Magnetic Resonance Imaging Study

Abstract

Objective. To investigate the potential structural and metabolic role of skeletal muscle in systemic lupus erythematosus (SLE)-related fatigue.Methods. A case-control, multimodal magnetic resonance imaging (MRI) study was conducted. Cases were patients with inactive SLE who reported chronic fatigue. Controls were age-and sex-matched healthy members of the general population. Patients were clinically characterized and then underwent a 3T whole-body MRI scan. Resting and dynamic 31 P MRI spectroscopy of the calf muscles was applied, from which phosphocreatine (PCr) recovery halftime, a marker of mitochondrial dysfunction, was computed. In addition, microstructural sequences (T1-weighted anatomic images, T2 mapping, and diffusion tensor imaging) were acquired. Descriptive statistics evaluated group differences and within-case physical fatigue correlations were explored.Results. Of the 37 recruits (mean age 43.8 years, 89.2% female), cases (n = 19) reported higher levels of physical fatigue, pain, depression, and sleep disturbance compared to the control group (P < 0.0001). PCr was greater (P = 0.045) among cases (mean ± SD 33.0 ± 9.0 seconds) compared to controls (mean ± SD 27.1 ± 6.6 seconds). No microstructural group differences were observed. Within cases, physical fatigue did not correlate with PCr (r = -0.28, P = 0.25).Conclusion. We report preliminary data demonstrating greater skeletal muscle mitochondrial dysfunction among fatigued patients with SLE compared to healthy controls.

Intermuscular adipose tissue in patients with systemic lupus erythematosus

“…Type II fibres are responsible for fast contraction and type II fibre atrophy is associated with reduced strength and physical performance; however, whether IMAT contributes to changes in fibre type in patients with SLE is unknown. In contrsast to our findings, a previous study did not find any difference in the fat accumulation in the soleus muscle in patients with SLE 29. The explanation may be that we measured fat accumulation in a larger muscle compartment that accounts for fat between fascicles and between muscles.…”

“…In contrsast to our findings, a previous study did not find any difference in the fat accumulation in the soleus muscle in patients with SLE. 29 The explanation may be that we measured fat accumulation in a larger muscle compartment that accounts for fat between fascicles and between muscles. (eg, between soleus and gastrocnemius).…”

Sarcopenia, severe anxiety and increased C-reactive protein are associated with severe fatigue in patients with inflammatory bowel diseases

“…This is the main hypothesis behind a study analyzing the relationship between muscle loss and systemic lupus erythematosus—related fatigue in a small sample of patients. The authors observed, via MRI, a voluntary reduced muscle contraction in subjects perceiving higher exertion, concluding toward a sarcopenia driven by fatigue, rather than the opposite 46 . The two interpretations however, instead of opposite, could be seen as a self-powered vicious cycle.…”

Sarcopenia, Severe Anxiety and Increased C-Reactive Protein Are Associated with Severe Fatigue in Patients with Inflammatory Bowel Diseases

“…The authors observed, via MRI, a voluntary reduced muscle contraction in subjects perceiving higher exertion, concluding toward a sarcopenia driven by fatigue, rather than the opposite. 42 The two interpretations however, instead of opposite, could be seen as a self-powered vicious cycle. This finding is consistent with the literature concerning strategies to treat fatigue: physical activity has already been identified as a valid therapeutic intervention for different cancers 43,44,45 and two exploratory studies showed promising effects in subjects affected by IBD.…”