Patients with chronic low back pain (CLBP) and comorbid fibromyalgia may have central sensitization and psychosocial symptoms, according to a study published in the Clinical Journal of Pain.
Participants with CLBP lasting ≥3 months and a low back pain severity score ≥3 on a 0 to 10 numeric rating pain scale were recruited from the community in Kansas City, Kansas (n=46). A total of 22 healthy control participants without CLBP were also enrolled in the study. All participants completed a demographic questionnaire, the 2011 fibromyalgia survey, a psychosocial questionnaire, and were tested for pressure pain thresholds and conditioned pain modulation.
Disability, pain catastrophizing, fear avoidance beliefs, and anxiety and depression were assessed using self-reported questionnaires. A total of 22 participants (48%) with CLBP also had fibromyalgia.
Participants with vs without fibromyalgia had lower pressure pain threshold values in the thumbnail (P =.011) and lower back (P =.003) and lower conditioned pain modulation values in the thumbnail (P =.002) as well as greater levels of pain catastrophizing, anxiety, and depression symptoms (P <.05).
The 2011 fibromyalgia survey scores were found to correlate with pressure pain threshold and conditioned pain modulation values of the thumbnail and with psychosocial symptoms (P <.001). The 2011 fibromyalgia survey scores also correlated with body mass index (r = 0.315; P =.033) and average pain intensity (r = 0.403; P <.01).
Study limitations include the small sample size, the recruitment of participants from a single geographic area in the United States, the cross-sectional design, and the self-reported nature of several symptom measures.
“The results suggest that [patients with CLBP] should be assessed based on their underlying causes rather than diagnosis in clinical practice,” concluded the study authors.
Aoyagi K, He J, Nicol AL, et al. A subgroup of chronic low back pain patients with central sensitization [published online August 12, 2019]. Clin J Pain. doi:10.1097/AJP.0000000000000755