Central sensitization predicts greater fatigue independently of musculoskeletal pain
Central sensitization is the enhancement of sensory input across multiple systems and is characterized by enhanced pain responses, unpleasant sensations to physical stimuli, including heat and mechanical stimuli, and increased sensitivity to environmental stimuli, including light and sound. It is also a common fatigue mechanism, which may explain the high level of fatigue associated with MSK disorders. However, the relationship may be clouded by MSK pain. Central sensitization is a well-known pain mechanism of MSK and MSK pain in turn seems mechanically associated with fatigue.
In this study, in a non-selected general population, it is tested whether central sensitization, independent of musculoskeletal pain, is associated with greater fatigue. This study attempted to determine the relationship between central sensitization and CFQ.
2.477 Prospective cohort study participants were asked to complete a baseline questionnaire consisting of the Chalder Fatigue Scale (CFQ), pain, demography, physical activity, anxiety, depression and medication use. In a clinical assessment conducted among 290 (11.7%) participants, central sensitization was measured by the winding ratio test at hand (WUR-H) and foot (WUR-F). Bioelectric impedance determined percentage of body fat. All participants involved were followed up to 12 months later, after which they completed the CFQ. Linear regression, with inverse probability sample weights, tested the relationship between WUR at baseline and CFQ at 12 months adjusted for baseline CFQ, demographic data, lifestyle factors, mental health and baseline pain.
At baseline, the median interquartile distances WUR-H and WUR-F were comparable (2.3 (1.5, 4.0) and 2.4 (1.6, 3.9), respectively) and did not differ per gender (WUR difference) -H: -0.29, 95% confidence interval -1.28-0.71; WUR-F: -0.57 (-1.50-0.36) or old age (WUR-H: -0.53, -1.49-0.43; WUR-F: -0.08 , -0.98-0.82) WUR-H scores (β = 0.11, 95% confidence interval: 0.07-0.16) and WUR-F scores (0.13, 0.08-0.17) were positively associated with CFQ scores at follow-up, independent of baseline CFQ and other covariates These associations were not explained by baseline pain.
Regardless of the presence of pain, fatigue is influenced by central sensitization. It has been shown that central sensitization, measured with WUR-H or WUR-F, predicts fatigue significantly, independent of MSK pain, demography, lifestyle factors and mental health. For a possible treatment of fatigue, the benefit of interventions that reduce central sensitization will have to be investigated.
Physical Therapy Science