Arterial stiffness and proinflammatory cytokines in fibromyalgia syndrome

We assessed arterial stiffness and inflammatory cytokine profiles in fibromyalgia syndrome (FMS) patients and analysed the association between them.

Twenty-seven FMS patients and 29 age-matched premenopausal healthy controls were enrolled in this study. Arterial stiffness was assessed by pulse wave velocity (PWV) and augmentation index (AIx) from pulse waveform analysis. Levels of serum interleukin-1β (IL-1β), IL-6, IL-8, and vascular endothelial growth factor (VEGF) were measured by enzyme-linked immunosorbent assay, and a colorimetric assay was used for measurement of serum nitric oxide (NO) metabolites (nitrate and nitrite, NOx) level. Statistical analyses included the Mann-Whitney U-test and Spearman's correlation coefficient analysis.

Higher AIx and AIx@HR75 (aortic AIx at a heart rate of 75 beats/min) were noted in FMS compared to those in the controls after adjustment using covariants (p(adj)=0.023 and p(adj)<0.001). However, there were no differences between the three regional PWVs of the two groups at the aorta-femoral, femoral-dorsalis, and aorta-radialis arteries (p(adj)>0.05 for all). FMS subjects had significantly higher serum IL-8 levels than did the healthy controls (327.9±588.7 vs. 76.4±90.5, p(adj)=0.041). However, there were no significant differences in serum IL-1β, IL-6, VEGF, or NOx levels between the FMS patients and the controls (p(adj)>0.05 of all). Serum IL-8 level did not correlate with PWV and AIx in FMS patients.

This study demonstrates higher AIx and IL-8 levels in FMS subjects compared to those of the controls. However, arterial stiffness including AIx in FMS was not determined by the serum IL-8 level.