Elevated tau and β-amyloid in the serum of fibromyalgia patients

Objective Fibromyalgia (FM) is a chronic widespread pain syndrome. Although its mechanism remains relatively unknown, accelerated neurodegeneration in the brain has been reported in patients with FM. Sleep disturbance can increase the risk of neurocognitive disorders, which are associated with tau and beta-amyloid (Aβ) protein accumulation. We hypothesize neurodegeneration in patients with FM may be associated with sleep disturbance. Methods In this case-control study, we analyzed serum tau and Aβ levels and their association with symptom profiles for patients with FM, by recruiting 22 patients with FM and 22 age-matched healthy participants. The visual analog scale, Fibromyalgia Impact Questionnaire, pressure pain threshold test, Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory-II, Beck Anxiety Inventory, and serum tau and beta-amyloid-42 (Aβ-42) levels were recorded. The Mann-Whitney test was conducted to compare questionnaire and protein level results between the groups. Pearson correlation test was conducted to investigate the correlation of questionnaire scores with tau and Aβ-42 levels in patients with FM. The significance level was set at P < .05. Results Serum tau and Aβ-42 levels were significantly higher in patients with FM than in controls. A positive correlation between serum tau levels and PSQI scores was observed in patients with FM (r = 0.476, P = .025). We found that only sleep disturbance in patients with FM was significantly associated with higher serum tau levels among all symptom scores. Conclusions We suggest sleep disturbance may play a vital role in the pathomechanism of accelerated neurodegeneration in FM.